Fixed Issues in Apache Impala (incubating)

The following sections describe the major issues fixed in each Impala release.

For known issues that are currently unresolved, see Known Issues and Workarounds in Impala.

Issues Fixed in Impala 2.9.0

For the full list of issues closed in this release, including bug fixes, see the changelog for Impala 2.9.

Issues Fixed in Impala 2.6.3

Issues Fixed in Impala 2.6.2

Issues Fixed in Impala 2.6.0

The following list contains the most critical fixed issues (priority='Blocker') from the JIRA system. For the full list of fixed issues in Impala 2.6.0, see this report in the Impala JIRA tracker.

RuntimeState::error_log_ crashes

A crash could occur, with stack trace pointing to impala::RuntimeState::ErrorLog.

Bug: IMPALA-3385

Severity: High

HiveUdfCall::Open() produces unsynchronized access to JniUtil::global_refs_ vector

A crash could occur because of contention between multiple calls to Java UDFs.

Bug: IMPALA-3378

Severity: High

HBaseTableWriter::CreatePutList() produces unsynchronized access to JniUtil::global_refs_ vector

A crash could occur because of contention between multiple concurrent statements writing to HBase.

Bug: IMPALA-3379

Severity: High

Stress test failure: sorter.cc:745] Check failed: i == 0 (1 vs. 0)

A crash or wrong results could occur if the spill-to-disk mechanism encountered a zero-length string at the very end of a data block.

Bug: IMPALA-3317

Severity: High

String data coming out of agg can be corrupted by blocking operators

If a query plan contains an aggregation node producing string values anywhere within a subplan (that is,if in the SQL statement, the aggregate function appears within an inline view over a collection column), the results of the aggregation may be incorrect.

Bug: IMPALA-3311

Severity: High

CTAS with subquery throws AuthzException

A CREATE TABLE AS SELECT operation could fail with an authorization error, due to a slight difference in the privilege checking for the CTAS operation.

Bug: IMPALA-3269

Severity: High

Crash on inserting into table with binary and parquet

Impala incorrectly allowed BINARY to be specified as a column type, resulting in a crash during a write to a Parquet table with a column of that type.

Bug: IMPALA-3237

Severity: High

RowBatch::MaxTupleBufferSize() calculation incorrect, may lead to memory corruption

A crash could occur while querying tables with very large rows, for example wide tables with many columns or very large string values. This problem was identified in Impala 2.3, but had low reproducibility in subsequent releases. The fix ensures the memory allocation size is correct.

Bug: IMPALA-3105

Severity: High

Thrift buffer overflows when serialize more than 3355443200 bytes in impala

A very large memory allocation within the catalogd daemon could exceed an internal Thrift limit, causing a crash.

Bug: IMPALA-3494

Severity: High

Altering table partition's storage format is not working and crashing the daemon

If a partitioned table used a file format other than Avro, and the file format of an individual partition was changed to Avro, subsequent queries could encounter a crash.

Bug: IMPALA-3314

Severity: High

Race condition may cause scanners to spin with runtime filters on Avro or Sequence files

A timing problem during runtime filter processing could cause queries against Avro or SequenceFile tables to hang.

Bug: IMPALA-3798

Severity: High

Issues Fixed in Impala 2.5.4

Issues Fixed in Impala 2.5.2

Issues Fixed in Impala 2.5.1

Issues Fixed in Impala 2.5.0

The following list contains the most critical issues (priority='Blocker') from the JIRA system. For the full list of fixed issues in Impala 2.5, see this report in the Impala JIRA tracker.

Stress test hit assert in LLVM: external function could not be resolved

Bug: IMPALA-2683

The stress test was running a build with the TPC-H, TPC-DS, and TPC-H nested queries with scale factor 3.

Impalad is crashing if udf jar is not available in hdfs location for first time

Bug: IMPALA-2365

If a UDF JAR was not available in the HDFS location specified in the CREATE FUNCTION statement, the impalad daemon could crash.

PAGG hits mem_limit when switching to I/O buffers

Bug: IMPALA-2535

A join query could fail with an out-of-memory error despite the apparent presence of sufficient memory. The cause was the internal ordering of operations that could cause a later phase of the query to allocate memory required by an earlier phase of the query. The workaround was to either increase or decrease the MEM_LIMIT query option, because the issue would only occur for a specific combination of memory limit and data volume.

Prevent migrating incorrectly inferred identity predicates into inline views

Bug: IMPALA-2643

Referring to the same column twice in a view definition could cause the view to omit rows where that column contained a NULL value. This could cause incorrect results due to an inaccurate COUNT(*) value or rows missing from the result set.

Fix migration/assignment of On-clause predicates inside inline views

Bug: IMPALA-1459

Some combinations of ON clauses in join queries could result in comparisons being applied at the wrong stage of query processing, leading to incorrect results. Wrong predicate assignment could happen under the following conditions:

  • The query includes an inline view that contains an outer join.
  • That inline view is joined with another table in the enclosing query block.
  • That join has an ON clause containing a predicate that only references columns originating from the outer-joined tables inside the inline view.

Wrong plan of NOT IN aggregate subquery when a constant is used in subquery predicate

Bug: IMPALA-2093

IN subqueries might return wrong results if the left-hand side of the IN is a constant. For example:


select * from alltypestiny t1
  where 10 not in (select sum(int_col) from alltypestiny);

Parquet DictDecoders accumulate throughout query

Bug: IMPALA-2940

Parquet dictionary decoders can accumulate throughout query execution, leading to excessive memory usage. One decoder is created per-column per-split.

Planner doesn't set the has_local_target field correctly

MemPool allocation growth behavior

Bug: IMPALA-2742

Currently, the MemPool would always double the size of the last allocation. This can lead to bad behavior if the MemPool transferred the ownership of all its data except the last chunk. In the next allocation, the next allocated chunk would double the size of this large chunk, which can be undesirable.

Drop partition operations don't follow the catalog's locking protocol

Bug: IMPALA-3035

The CatalogOpExecutor.alterTableDropPartition() function violates the locking protocol used in the catalog that requires catalogLock_ to be acquired before any table-level lock. That may cause deadlocks when ALTER TABLE DROP PARTITION is executed concurrently with other DDL operations.

HAVING clause without aggregation not applied properly

Bug: IMPALA-2215

A query with a HAVING clause but no GROUP BY clause was not being rejected, despite being invalid syntax. For example:


select case when 1=1 then 'didit' end as c1 from (select 1 as one) a having 1!=1;

Hit DCHECK Check failed: HasDateOrTime()

Bug: IMPALA-2914

TimestampValue::ToTimestampVal() requires a valid TimestampValue as input. This requirement was not enforced in some places, leading to serious errors.

Aggregation spill loop gives up too early leading to mem limit exceeded errors

Bug: IMPALA-2986

An aggregation query could fail with an out-of-memory error, despite sufficient memory being reported as available.

DataStreamSender::Channel::CloseInternal() does not close the channel on an error.

Bug: IMPALA-2592

Some queries do not close an internal communication channel on an error. This will cause the node on the other side of the channel to wait indefinitely, causing the query to hang. For example, this issue could happen on a Kerberos-enabled system if the credential cache was outdated. Although the affected query hangs, the impalad daemons continue processing other queries.

Codegen does not catch exceptions in FROM_UNIXTIME()

Bug: IMPALA-2184

Querying for the min or max value of a timestamp cast from a bigint via from_unixtime() fails silently and crashes instances of impalad when the input includes a value outside of the valid range.

Workaround: Disable native code generation with:


SET disable_codegen=true;

Impala returns wrong result for function 'conv(bigint, from_base, to_base)'

Bug: IMPALA-2788

Impala returns wrong result for function conv(). Function conv(bigint, from_base, to_base) returns an correct result, while conv(string, from_base, to_base) returns the correct value. For example:



select 2061013007, conv(2061013007, 16, 10), conv('2061013007', 16, 10);
+------------+--------------------------+----------------------------+
| 2061013007 | conv(2061013007, 16, 10) | conv('2061013007', 16, 10) |
+------------+--------------------------+----------------------------+
| 2061013007 | 1627467783               | 139066421255               |
+------------+--------------------------+----------------------------+
Fetched 1 row(s) in 0.65s

select 2061013007, conv(cast(2061013007 as bigint), 16, 10), conv('2061013007', 16, 10);
+------------+------------------------------------------+----------------------------+
| 2061013007 | conv(cast(2061013007 as bigint), 16, 10) | conv('2061013007', 16, 10) |
+------------+------------------------------------------+----------------------------+
| 2061013007 | 1627467783                               | 139066421255               |
+------------+------------------------------------------+----------------------------+

select 2061013007, conv(cast(2061013007 as string), 16, 10), conv('2061013007', 16, 10);
+------------+------------------------------------------+----------------------------+
| 2061013007 | conv(cast(2061013007 as string), 16, 10) | conv('2061013007', 16, 10) |
+------------+------------------------------------------+----------------------------+
| 2061013007 | 139066421255                             | 139066421255               |
+------------+------------------------------------------+----------------------------+

select 2061013007, conv(cast(cast(2061013007 as decimal(20,0)) as bigint), 16, 10), conv('2061013007', 16, 10);
+------------+-----------------------------------------------------------------+----------------------------+
| 2061013007 | conv(cast(cast(2061013007 as decimal(20,0)) as bigint), 16, 10) | conv('2061013007', 16, 10) |
+------------+-----------------------------------------------------------------+----------------------------+
| 2061013007 | 1627467783                                                      | 139066421255               |
+------------+-----------------------------------------------------------------+----------------------------+

Workaround: Cast the value to string and use conv(string, from_base, to_base) for conversion.

Issues Fixed in Impala 2.4.1

Issues Fixed in Impala 2.4.0

The set of fixes for Impala in Impala 2.4.0 is the same as in Impala 2.3.2.

Issues Fixed in Impala 2.3.4

Issues Fixed in Impala 2.3.2

This section lists the most serious or frequently encountered customer issues fixed in Impala 2.3.2.

SEGV in AnalyticEvalNode touching NULL input_stream_

A query involving an analytic function could encounter a serious error. This issue was encountered infrequently, depending upon specific combinations of queries and data.

Bug: IMPALA-2829

Free local allocations per row batch in non-partitioned AGG and HJ

An outer join query could fail unexpectedly with an out-of-memory error when the "spill to disk" mechanism was turned off.

Bug: IMPALA-2722

Free local allocations once for every row batch when building hash tables

A join query could encounter a serious error due to an internal failure to allocate memory, which resulted in dereferencing a NULL pointer.

Bug: IMPALA-2612

Prevent migrating incorrectly inferred identity predicates into inline views

Referring to the same column twice in a view definition could cause the view to omit rows where that column contained a NULL value. This could cause incorrect results due to an inaccurate COUNT(*) value or rows missing from the result set.

Bug: IMPALA-2643

Fix GRANTs on URIs with uppercase letters

A GRANT statement for a URI could be ineffective if the URI contained uppercase letters, for example in an uppercase directory name. Subsequent statements, such as CREATE EXTERNAL TABLE with a LOCATION clause, could fail with an authorization exception.

Bug: IMPALA-2695

Avoid sending large partition stats objects over thrift

The catalogd daemon could encounter a serious error when loading the incremental statistics metadata for tables with large numbers of partitions and columns. The problem occurred when the internal representation of metadata for the table exceeded 2 GB, for example in a table with 20K partitions and 77 columns. The fix causes a COMPUTE INCREMENTAL STATS operation to fail if it would produce metadata that exceeded the maximum size.

Bug: IMPALA-2664, IMPALA-2648

Throw AnalysisError if table properties are too large (for the Hive metastore)

CREATE TABLE or ALTER TABLE statements could fail with metastore database errors due to length limits on the SERDEPROPERTIES and TBLPROPERTIES clauses. (The limit on key size is 256, while the limit on value size is 4000.) The fix makes Impala handle these error conditions more cleanly, by detecting too-long values rather than passing them to the metastore database.

Bug: IMPALA-2226

Make MAX_PAGE_HEADER_SIZE configurable

Impala could fail to access Parquet data files with page headers larger than 8 MB, which could occur, for example, if the minimum or maximum values for a column were long strings. The fix adds a configuration setting --max_page_header_size, which you can use to increase the Impala size limit to a value higher than 8 MB.

Bug: IMPALA-2273

reduce scanner memory usage

Queries on Parquet tables could consume excessive memory (potentially multiple gigabytes) due to producing large intermediate data values while evaluating groups of rows. The workaround was to reduce the size of the NUM_SCANNER_THREADS query option, the BATCH_SIZE query option, or both.

Bug: IMPALA-2473

Handle error when distinct and aggregates are used with a having clause

A query that included a DISTINCT operator and a HAVING clause, but no aggregate functions or GROUP BY, would fail with an uninformative error message.

Bug: IMPALA-2113

Handle error when star based select item and aggregate are incorrectly used

A query that included * in the SELECT list, in addition to an aggregate function call, would fail with an uninformative message if the query had no GROUP BY clause.

Bug: IMPALA-2225

Refactor MemPool usage in HBase scan node

Queries involving HBase tables used substantially more memory than in earlier Impala versions. The problem occurred starting in Impala 2.2.8, as a result of the changes for IMPALA-2284. The fix for this issue involves removing a separate memory work area for HBase queries and reusing other memory that was already allocated.

Bug: IMPALA-2731

Fix migration/assignment of On-clause predicates inside inline views

Some combinations of ON clauses in join queries could result in comparisons being applied at the wrong stage of query processing, leading to incorrect results. Wrong predicate assignment could happen under the following conditions:

  • The query includes an inline view that contains an outer join.
  • That inline view is joined with another table in the enclosing query block.
  • That join has an ON clause containing a predicate that only references columns originating from the outer-joined tables inside the inline view.

Bug: IMPALA-1459

DCHECK in parquet scanner after block read error

A debug build of Impala could encounter a serious error after encountering some kinds of I/O errors for Parquet files. This issue only occurred in debug builds, not release builds.

Bug: IMPALA-2558

PAGG hits mem_limit when switching to I/O buffers

A join query could fail with an out-of-memory error despite the apparent presence of sufficient memory. The cause was the internal ordering of operations that could cause a later phase of the query to allocate memory required by an earlier phase of the query. The workaround was to either increase or decrease the MEM_LIMIT query option, because the issue would only occur for a specific combination of memory limit and data volume.

Bug: IMPALA-2535

Fix check failed: sorter_runs_.back()->is_pinned_

A query could fail with an internal error while calculating the memory limit. This was an infrequent condition uncovered during stress testing.

Bug: IMPALA-2559

Don't ignore Status returned by DataStreamRecvr::CreateMerger()

A query could fail with an internal error while calculating the memory limit. This was an infrequent condition uncovered during stress testing.

Bug: IMPALA-2614, IMPALA-2559

DataStreamSender::Send() does not return an error status if SendBatch() failed

Re-enable SSL and Kerberos on server-server

These fixes lift the restriction on using SSL encryption and Kerberos authentication together for internal communication between Impala components.

Bug: IMPALA-2598, IMPALA-2747

Issues Fixed in Impala 2.3.1

The version of Impala that is included with Impala 2.3.1 is identical to Impala 2.3.0. There are no new bug fixes, new features, or incompatible changes.

Issues Fixed in Impala 2.3.0

This section lists the most serious or frequently encountered customer issues fixed in Impala 2.3. Any issues already fixed in Impala 2.2 maintenance releases (up through Impala 2.2.8) are also included. Those issues are listed under the respective Impala 2.2 sections and are not repeated here.

Issues Fixed in Impala 2.2.10

Issues Fixed in Impala 2.2.9

This section lists the most frequently encountered customer issues fixed in Impala 2.2.9.

Query return empty result if it contains NullLiteral in inlineview

If an inline view in a FROM clause contained a NULL literal, the result set was empty.

Bug: IMPALA-1917

HBase scan node uses 2-4x memory after upgrade to Impala 2.2.8

Queries involving HBase tables used substantially more memory than in earlier Impala versions. The problem occurred starting in Impala 2.2.8, as a result of the changes for IMPALA-2284. The fix for this issue involves removing a separate memory work area for HBase queries and reusing other memory that was already allocated.

Bug: IMPALA-2731

Fix migration/assignment of On-clause predicates inside inline views

Some combinations of ON clauses in join queries could result in comparisons being applied at the wrong stage of query processing, leading to incorrect results. Wrong predicate assignment could happen under the following conditions:

  • The query includes an inline view that contains an outer join.
  • That inline view is joined with another table in the enclosing query block.
  • That join has an ON clause containing a predicate that only references columns originating from the outer-joined tables inside the inline view.

Bug: IMPALA-1459

Fix wrong predicate assignment in outer joins

The join predicate for an OUTER JOIN clause could be applied at the wrong stage of query processing, leading to incorrect results.

Bug: IMPALA-2446

Avoid sending large partition stats objects over thrift

The catalogd daemon could encounter a serious error when loading the incremental statistics metadata for tables with large numbers of partitions and columns. The problem occurred when the internal representation of metadata for the table exceeded 2 GB, for example in a table with 20K partitions and 77 columns. The fix causes a COMPUTE INCREMENTAL STATS operation to fail if it would produce metadata that exceeded the maximum size.

Bug: IMPALA-2648, IMPALA-2664

Avoid overflow when adding large intervals to TIMESTAMPs

Adding or subtracting a large INTERVAL value to a TIMESTAMP value could produce an incorrect result, with the value wrapping instead of returning an out-of-range error.

Bug: IMPALA-1675

Analysis exception when a binary operator contains an IN operator with values

An IN operator with literal values could cause a statement to fail if used as the argument to a binary operator, such as an equality test for a BOOLEAN value.

Bug: IMPALA-1949

Make MAX_PAGE_HEADER_SIZE configurable

Impala could fail to access Parquet data files with page headers larger than 8 MB, which could occur, for example, if the minimum or maximum values for a column were long strings. The fix adds a configuration setting --max_page_header_size, which you can use to increase the Impala size limit to a value higher than 8 MB.

Bug: IMPALA-2273

Fix spilling sorts with var-len slots that are NULL or empty.

A query that activated the spill-to-disk mechanism could fail if it contained a sort expression involving certain combinations of fixed-length or variable-length types.

Bug: IMPALA-2357

Work-around IMPALA-2344: Fail query with OOM in case block->Pin() fails

Some queries that activated the spill-to-disk mechanism could produce a serious error if there was insufficient memory to set up internal work areas. Now those queries produce normal out-of-memory errors instead.

Bug: IMPALA-2344

Crash (likely race) tearing down BufferedBlockMgr on query failure

A serious error could occur under rare circumstances, due to a race condition while freeing memory during heavily concurrent workloads.

Bug: IMPALA-2252

QueryExecState doesn't check for query cancellation or errors

A call to SetError() in a user-defined function (UDF) would not cause the query to fail as expected.

Bug: IMPALA-1746

Impala throws IllegalStateException when inserting data into a partition while select subquery group by partition columns

An INSERT ... SELECT operation into a partitioned table could fail if the SELECT query included a GROUP BY clause referring to the partition key columns.

Bug: IMPALA-2533

Issues Fixed in Impala 2.2.8

This section lists the most frequently encountered customer issues fixed in Impala 2.2.8.

Impala is unable to read hive tables created with the "STORED AS AVRO" clause

Impala could not read Avro tables created in Hive with the STORED AS AVRO clause.

Bug: IMPALA-1136, IMPALA-2161

make Parquet scanner fail query if the file size metadata is stale

If a Parquet file in HDFS was overwritten by a smaller file, Impala could encounter a serious error. Issuing a INVALIDATE METADATA statement before a subsequent query would avoid the error. The fix allows Impala to handle such inconsistencies in Parquet file length cleanly regardless of whether the table metadata is up-to-date.

Bug: IMPALA-2213

Avoid allocating StringBuffer > 1GB in ScannerContext::Stream::GetBytesInternal()

Impala could encounter a serious error when reading compressed text files larger than 1 GB. The fix causes Impala to issue an error message instead in this case.

Bug: IMPALA-2249

Disallow long (1<<30) strings in group_concat()

A query using the group_concat() function could encounter a serious error if the returned string value was larger than 1 GB. Now the query fails with an error message in this case.

Bug: IMPALA-2284

avoid FnvHash64to32 with empty inputs

An edge case in the algorithm used to distribute data among nodes could result in uneven distribution of work for some queries, with all data sent to the same node.

Bug: IMPALA-2270

The catalog does not close the connection to HMS during table invalidation

A communication error could occur between Impala and the Hive metastore database, causing Impala operations that update table metadata to fail.

Bug: IMPALA-2348

Wrong DCHECK in PHJ::ProcessProbeBatch

Certain queries could encounter a serious error if the spill-to-disk mechanism was activated.

Bug: IMPALA-2364

Avoid cardinality 0 in scan nodes of small tables and low selectivity

Impala could generate a suboptimal query plan for some queries involving small tables.

Bug: IMPALA-2165

Issues Fixed in Impala 2.2.7

This section lists the most frequently encountered customer issues fixed in Impala 2.2.7.

Warn if table stats are potentially corrupt.

Impala warns if it detects a discrepancy in table statistics: a table considered to have zero rows even though there are data files present. In this case, Impala also skips query optimizations that are normally applied to very small tables.

Bug: IMPALA-1983:

Pass correct child node in 2nd phase merge aggregation.

A query could encounter a serious error if it included a particular combination of aggregate functions and inline views.

Bug: IMPALA-2266

Set the output smap of an EmptySetNode produced from an empty inline view.

A query could encounter a serious error if it included an inline view whose subquery had no FROM clause.

Bug: IMPALA-2216

Set an InsertStmt's result exprs from the source statement's result exprs.

A CREATE TABLE AS SELECT or INSERT ... SELECT statement could produce different results than a SELECT statement, for queries including a FULL JOIN clause and including literal values in the select list.

Bug: IMPALA-2203

Fix planning of empty union operands with analytics.

A query could return incorrect results if it contained a UNION clause, calls to analytic functions, and a constant expression that evaluated to FALSE.

Bug: IMPALA-2088

Retain eq predicates bound by grouping slots with complex grouping exprs.

A query containing an INNER JOIN clause could return undesired rows. Some predicate specified in the ON clause could be omitted from the filtering operation.

Bug: IMPALA-2089

Row count not set for empty partition when spec is used with compute incremental stats

A COMPUTE INCREMENTAL STATS statement could leave the row count for an emptyp partition as -1, rather than initializing the row count to 0. The missing statistic value could result in reduced query performance.

Bug: IMPALA-2199

Explicit aliases + ordinals analysis bug

A query could encounter a serious error if it included column aliases with the same names as table columns, and used ordinal numbers in an ORDER BY or GROUP BY clause.

Bug: IMPALA-1898

Fix TupleIsNullPredicate to return false if no tuples are nullable.

A query could return incorrect results if it included an outer join clause, inline views, and calls to functions such as coalesce() that can generate NULL values.

Bug: IMPALA-1987

fix Expr::ComputeResultsLayout() logic

A query could return incorrect results if the table contained multiple CHAR columns with length of 2 or less, and the query included a GROUP BY clause that referred to multiple such columns.

Bug: IMPALA-2178

Substitute an InsertStmt's partition key exprs with the root node's smap.

An INSERT statement could encounter a serious error if the SELECT portion called an analytic function.

Bug: IMPALA-1737

Issues Fixed in Impala Impala 2.2.5

This section lists the most frequently encountered customer issues fixed in Impala 2.2.5.

Impala DML/DDL operations corrupt table metadata leading to Hive query failures

When the Impala COMPUTE STATS statement was run on a partitioned Parquet table that was created in Hive, the table subsequently became inaccessible in Hive. The table was still accessible to Impala. Regaining access in Hive required a workaround of creating a new table. The error displayed in Hive was:

Error: Error while compiling statement: FAILED: SemanticException Class not found: org.apache.impala.hive.serde.ParquetInputFormat (state=42000,code=40000)

Bug: IMPALA-2048

Avoiding a DCHECK of NULL hash table in spilled right joins

A query could encounter a serious error if it contained a RIGHT OUTER, RIGHT ANTI, or FULL OUTER join clause and approached the memory limit on a host so that the "spill to disk" mechanism was activated.

Bug: IMPALA-1929

Bug in PrintTColumnValue caused wrong stats for TINYINT partition cols

Declaring a partition key column as a TINYINT caused problems with the COMPUTE STATS statement. The associated partitions would always have zero estimated rows, leading to potential inefficient query plans.

Bug: IMPALA-2136

Where clause does not propagate to joins inside nested views

A query that referred to a view whose query referred to another view containing a join, could return incorrect results. WHERE clauses for the outermost query were not always applied, causing the result set to include additional rows that should have been filtered out.

Bug: IMPALA-2018

Add effective_user() builtin

The user() function returned the name of the logged-in user, which might not be the same as the user name being checked for authorization if, for example, delegation was enabled.

Bug: IMPALA-2064

Resolution: Rather than change the behavior of the user() function, the fix introduces an additional function effective_user() that returns the user name that is checked during authorization.

Make UTC to local TimestampValue conversion faster.

Query performance was improved substantially for Parquet files containing TIMESTAMP data written by Hive, when the -convert_legacy_hive_parquet_utc_timestamps=true setting is in effect.

Bug: IMPALA-2125

Workaround IMPALA-1619 in BufferedBlockMgr::ConsumeMemory()

A join query could encounter a serious error if the query approached the memory limit on a host so that the "spill to disk" mechanism was activated, and data volume in the join was large enough that an internal memory buffer exceeded 1 GB in size on a particular host. (Exceeding this limit would only happen for huge join queries, because Impala could split this intermediate data into 16 parts during the join query, and the buffer only contains compact bookkeeping data rather than the actual join column data.)

Bug: IMPALA-2065

Issues Fixed in Impala 2.2.3

This section lists the most frequently encountered customer issues fixed in Impala 2.2.3.

Enable using Isilon as the underlying filesystem.

Enabling Impala to work with the Isilon filesystem involves a number of fixes to performance and flexibility for dealing with I/O using remote reads. See Using Impala with Isilon Storage for details on using Impala and Isilon together.

Bug: IMPALA-1968, IMPALA-1730

Expand set of supported timezones.

The set of timezones recognized by Impala was expanded. You can always find the latest list of supported timezones in the Impala source code, in the file timezone_db.cc.

Bug: IMPALA-1381

Impala Timestamp ISO-8601 Support.

Impala can now process TIMESTAMP literals including a trailing z, signifying "Zulu" time, a synonym for UTC.

Bug: IMPALA-1963

Fix wrong warning when insert overwrite to empty table

An INSERT OVERWRITE operation would encounter an error if the SELECT portion of the statement returned zero rows, such as with a LIMIT 0 clause.

Bug: IMPALA-2008

Expand parsing of decimals to include scientific notation

DECIMAL literals can now include e scientific notation. For example, now CAST(1e3 AS DECIMAL(5,3)) is a valid expression. Formerly it returned NULL. Some scientific expressions might have worked before in DECIMAL context, but only when the scale was 0.

Bug: IMPALA-1952

Issues Fixed in Impala 2.2.1

This section lists the most frequently encountered customer issues fixed in Impala 2.2.1.

Issues Fixed in Impala 2.2.0

This section lists the most frequently encountered customer issues fixed in Impala 2.2.0.

For the full list of fixed issues in Impala 2.2.0, including over 40 critical issues, see this report in the Impala JIRA tracker.

Altering a column's type causes column stats to stop sticking for that column

When the type of a column was changed in either Hive or Impala through ALTER TABLE CHANGE COLUMN, the metastore database did not correctly propagate that change to the table that contains the column statistics. The statistics (particularly the NDV) for that column were permanently reset and could not be changed by Impala's COMPUTE STATS command. The underlying cause is a Hive bug (HIVE-9866).

Bug: IMPALA-1607

Resolution: Resolved by incorporating the fix for HIVE-9866.

Workaround: On systems without the corresponding Hive fix, change the column back to its original type. The stats reappear and you can recompute or drop them.

Impala may leak or use too many file descriptors

If a file was truncated in HDFS without a corresponding REFRESH in Impala, Impala could allocate memory for file descriptors and not free that memory.

Bug: IMPALA-1854

Spurious stale block locality messages

Impala could issue messages stating the block locality metadata was stale, when the metadata was actually fine. The internal "remote bytes read" counter was not being reset properly. This issue did not cause an actual slowdown in query execution, but the spurious error could result in unnecessary debugging work and unnecessary use of the INVALIDATE METADATA statement.

Bug: IMPALA-1712

DROP TABLE fails after COMPUTE STATS and ALTER TABLE RENAME to a different database.

When a table was moved from one database to another, the column statistics were not pointed to the new database.i This could result in lower performance for queries due to unavailable statistics, and also an inability to drop the table.

Bug: IMPALA-1711

IMPALA-1556 causes memory leak with secure connections

impalad daemons could experience a memory leak on clusters using Kerberos authentication, with memory usage growing as more data is transferred across the secure channel, either to the client program or between Impala nodes. The same issue affected LDAP-secured clusters to a lesser degree, because the LDAP security only covers data transferred back to client programs.

Bug: IMPALA-1674

unix_timestamp() does not return correct time

The unix_timestamp() function could return an incorrect value (a constant value of 1).

Bug: IMPALA-1623

Impala incorrectly handles text data missing a newline on the last line

Some queries did not recognize the final line of a text data file if the line did not end with a newline character. This could lead to inconsistent results, such as a different number of rows for SELECT COUNT(*) as opposed to SELECT *.

Bug: IMPALA-1476

Impala's ACLs check do not consider all group ACLs, only checked first one.

If the HDFS user ID associated with the impalad process had read or write access in HDFS based on group membership, Impala statements could still fail with HDFS permission errors if that group was not the first listed group for that user ID.

Bug: IMPALA-1805

Fix infinite loop opening or closing file with invalid metadata

Truncating a file in HDFS, after Impala had cached the file metadata, could produce a hang when Impala queried a table containing that file.

Bug: IMPALA-1794

Cannot write Parquet files when values are larger than 64KB

Impala could sometimes fail to INSERT into a Parquet table if a column value such as a STRING was larger than 64 KB.

Bug: IMPALA-1705

Impala Will Not Run on Certain Intel CPUs

This fix relaxes the CPU requirement for Impala. Now only the SSSE3 instruction set is required. Formerly, SSE4.1 instructions were generated, making Impala refuse to start on some older CPUs.

Bug: IMPALA-1646

Issues Fixed in Impala 2.1.10

Issues Fixed in Impala 2.1.7

This section lists the most significant Impala issues fixed in Impala 2.1.7.

Query return empty result if it contains NullLiteral in inlineview

If an inline view in a FROM clause contained a NULL literal, the result set was empty.

Bug: IMPALA-1917

Fix edge cases for decimal/integer cast

A value of type DECIMAL(3,0) could be incorrectly cast to TINYINT. The resulting out-of-range value could be incorrect. After the fix, the smallest type that is allowed for this cast is INT, and attempting to use DECIMAL(3,0) in a TINYINT context produces a "loss of precision" error.

Bug: IMPALA-2264

Constant filter expressions are not checked for errors and state cleanup on exception / DCHECK on destroying an ExprContext

An invalid constant expression in a WHERE clause (for example, an invalid regular expression pattern) could fail to clean up internal state after raising a query error. Therefore, certain combinations of invalid expressions in a query could cause a crash, or cause a query to continue when it should halt with an error.

Bug: IMPALA-1756, IMPALA-2514

QueryExecState does not check for query cancellation or errors

A call to SetError() in a user-defined function (UDF) would not cause the query to fail as expected.

Bug: IMPALA-1746, IMPALA-2141

Issues Fixed in Impala 2.1.6

This section lists the most significant Impala issues fixed in Impala 2.1.6.

Wrong DCHECK in PHJ::ProcessProbeBatch

Certain queries could encounter a serious error if the spill-to-disk mechanism was activated.

Bug: IMPALA-2364

LargestSpilledPartition was not checking if partition is closed

Certain queries could encounter a serious error if the spill-to-disk mechanism was activated.

Bug: IMPALA-2314

Avoid cardinality 0 in scan nodes of small tables and low selectivity

Impala could generate a suboptimal query plan for some queries involving small tables.

Bug: IMPALA-2165

fix Expr::ComputeResultsLayout() logic

Queries using the GROUP BY operator on multiple CHAR columns with length less than or equal to 2 characters could return incorrect results for some columns.

Bug: IMPALA-2178

Properly unescape string value for HBase filters

Queries against HBase tables could return incomplete results if the WHERE clause included string comparisons using literals containing escaped quotation marks.

Bug: IMPALA-2133

Avoiding a DCHECK of NULL hash table in spilled right joins

A query could encounter a serious error if it contained a RIGHT OUTER, RIGHT ANTI, or FULL OUTER join clause and approached the memory limit on a host so that the "spill to disk" mechanism was activated.

Bug: IMPALA-1929

Issues Fixed in Impala 2.1.5

This section lists the most significant Impala issues fixed in Impala 2.1.5.

Avoid calling ProcessBatch with out_batch->AtCapacity in right joins

Queries including RIGHT OUTER JOIN, RIGHT ANTI JOIN, or FULL OUTER JOIN clauses and involving a high volume of data could encounter a serious error.

Bug: IMPALA-1919

Issues Fixed in Impala 2.1.4

This section lists the most significant Impala issues fixed in Impala 2.1.4.

Crash: impala::TupleIsNullPredicate::Prepare

When expressions that tested for NULL were used in combination with analytic functions, an error could occur. (The original crash issue was fixed by an earlier patch.)

Bug: IMPALA-1519

Expand parsing of decimals to include scientific notation

DECIMAL literals could include e scientific notation. For example, now CAST(1e3 AS DECIMAL(5,3)) is a valid expression. Formerly it returned NULL. Some scientific expressions might have worked before in DECIMAL context, but only when the scale was 0.

Bug: IMPALA-1952

INSERT/CTAS evaluates and applies constant predicates.

An INSERT OVERWRITE statement would write new data, even if a constant clause such as WHERE 1 = 0 should have prevented it from writing any rows.

Bug: IMPALA-1860

Assign predicates below analytic functions with a compatible partition by clause

If the PARTITION BY clause in an analytic function refers to partition key columns in a partitioned table, now Impala can perform partition pruning during the analytic query.

Bug: IMPALA-1900

FIRST_VALUE may produce incorrect results with preceding windows

A query using the FIRST_VALUE analytic function and a window defined with the PRECEDING keyword could produce wrong results.

Bug: IMPALA-1888

FIRST_VALUE rewrite fn type might not match slot type

A query referencing a DECIMAL column with the FIRST_VALUE analytic function could encounter an error.

Bug: IMPALA-1559

AnalyticEvalNode cannot handle partition/order by exprs with NaN

A query using an analytic function could encounter an error if the evaluation of an analytic ORDER BY or PARTITION expression resulted in a NaN value, for example if the ORDER BY or PARTITION contained a division operation where both operands were zero.

Bug: IMPALA-1808

AnalyticEvalNode not properly handling nullable tuples

An analytic function containing only an OVER clause could encounter an error if another part of the query (specifically an outer join) produced all-NULL tuples.

Bug: IMPALA-1562

Issues Fixed in Impala 2.1.3

This section lists the most significant issues fixed in Impala 2.1.3.

Add compatibility flag for Hive-Parquet-Timestamps

When Hive writes TIMESTAMP values, it represents them in the local time zone of the server. Impala expects TIMESTAMP values to always be in the UTC time zone, possibly leading to inconsistent results depending on which component created the data files. This patch introduces a new startup flag, -convert_legacy_hive_parquet_utc_timestamps for the impalad daemon. Specify -convert_legacy_hive_parquet_utc_timestamps=true to make Impala recognize Parquet data files written by Hive and automatically adjust TIMESTAMP values read from those files into the UTC time zone for compatibility with other Impala TIMESTAMP processing. Although this setting is currently turned off by default, consider enabling it if practical in your environment, for maximum interoperability with Hive-created Parquet files.

Bug: IMPALA-1658

Use snprintf() instead of lexical_cast() in float-to-string casts

Converting a floating-point value to a STRING could be slower than necessary.

Bug: IMPALA-1738

Fix partition spilling cleanup when new stream OOMs

Certain calls to aggregate functions with STRING arguments could encounter a serious error when the system ran low on memory and attempted to activate the spill-to-disk mechanism. The error message referenced the function impala::AggregateFunctions::StringValGetValue.

Bug: IMPALA-1865

Impala's ACLs check do not consider all group ACLs, only checked first one.

If the HDFS user ID associated with the impalad process had read or write access in HDFS based on group membership, Impala statements could still fail with HDFS permission errors if that group was not the first listed group for that user ID.

Bug: IMPALA-1805

Fix infinite loop opening or closing file with invalid metadata

Truncating a file in HDFS, after Impala had cached the file metadata, could produce a hang when Impala queried a table containing that file.

Bug: IMPALA-1794

external-data-source-executor leaking global jni refs

Successive calls to the data source API could result in excessive memory consumption, with memory allocated but never freed.

Bug: IMPALA-1801

Spurious stale block locality messages

Impala could issue messages stating the block locality metadata was stale, when the metadata was actually fine. The internal "remote bytes read" counter was not being reset properly. This issue did not cause an actual slowdown in query execution, but the spurious error could result in unnecessary debugging work and unnecessary use of the INVALIDATE METADATA statement.

Bug: IMPALA-1712

Issues Fixed in Impala 2.1.2

This section lists the most significant issues fixed in Impala 2.1.2.

For the full list of fixed issues in Impala 2.1.2, see this report in the Impala JIRA tracker.

Impala incorrectly handles double numbers with more than 19 significant decimal digits

When a floating-point value was read from a text file and interpreted as a FLOAT or DOUBLE value, it could be incorrectly interpreted if it included more than 19 significant digits.

Bug: IMPALA-1622

unix_timestamp() does not return correct time

The unix_timestamp() function could return an incorrect value (a constant value of 1).

Bug: IMPALA-1623

Row Count Mismatch: Partition pruning with NULL

A query against a partitioned table could return incorrect results if the WHERE clause compared the partition key to NULL using operators such as = or !=.

Bug: IMPALA-1535

Fetch column stats in bulk using new (Hive .13) HMS APIs

The performance of the COMPUTE STATS statement and queries was improved, particularly for wide tables.

Bug: IMPALA-1120

Issues Fixed in Impala 2.1.1

This section lists the most significant issues fixed in Impala 2.1.1.

For the full list of fixed issues in Impala 2.1.1, see this report in the Impala JIRA tracker.

IMPALA-1556 causes memory leak with secure connections

impalad daemons could experience a memory leak on clusters using Kerberos authentication, with memory usage growing as more data is transferred across the secure channel, either to the client program or between Impala nodes. The same issue affected LDAP-secured clusters to a lesser degree, because the LDAP security only covers data transferred back to client programs.

Bug: https://issues.apache.org/jira/browse/IMPALA-1674 IMPALA-1674

TSaslServerTransport::Factory::getTransport() leaks transport map entries

impalad daemons in clusters secured by Kerberos or LDAP could experience a slight memory leak on each connection. The accumulation of unreleased memory could cause problems on long-running clusters.

Bug: IMPALA-1668

Issues Fixed in Impala 2.1.0

This section lists the most significant issues fixed in Impala 2.1.0.

For the full list of fixed issues in Impala 2.1.0, see this report in the Impala JIRA tracker.

Kerberos fetches 3x slower

Transferring large result sets back to the client application on Kerberos

Bug: IMPALA-1455

Compressed file needs to be hold on entirely in Memory

Queries on gzipped text files required holding the entire data file and its uncompressed representation in memory at the same time. SELECT and COMPUTE STATS statements could fail or perform inefficiently as a result. The fix enables streaming reads for gzipped text, so that the data is uncompressed as it is read.

Bug: IMPALA-1556

Cannot read hbase metadata with NullPointerException: null

Impala might not be able to access HBase tables, depending on the associated levels of Impala and HBase on the system.

Bug: IMPALA-1611

Issues Fixed in Impala 2.0.4

This section lists the most significant issues fixed in Impala 2.0.4.

For the full list of fixed issues in Impala 2.0.4, see this report in the Impala JIRA tracker.

Add compatibility flag for Hive-Parquet-Timestamps

When Hive writes TIMESTAMP values, it represents them in the local time zone of the server. Impala expects TIMESTAMP values to always be in the UTC time zone, possibly leading to inconsistent results depending on which component created the data files. This patch introduces a new startup flag, -convert_legacy_hive_parquet_utc_timestamps for the impalad daemon. Specify -convert_legacy_hive_parquet_utc_timestamps=true to make Impala recognize Parquet data files written by Hive and automatically adjust TIMESTAMP values read from those files into the UTC time zone for compatibility with other Impala TIMESTAMP processing. Although this setting is currently turned off by default, consider enabling it if practical in your environment, for maximum interoperability with Hive-created Parquet files.

Bug: IMPALA-1658

IoMgr infinite loop opening/closing file when shorter than cached metadata size

If a table data file was replaced by a shorter file outside of Impala, such as with INSERT OVERWRITE in Hive producing an empty output file, subsequent Impala queries could hang.

Bug: IMPALA-1794

Issues Fixed in Impala 2.0.3

This section lists the most significant issues fixed in Impala 2.0.3.

For the full list of fixed issues in Impala 2.0.3, see this report in the Impala JIRA tracker.

Anti join could produce incorrect results when spilling

An anti-join query (or a NOT EXISTS operation that was rewritten internally into an anti-join) could produce incorrect results if Impala reached its memory limit, causing the query to write temporary results to disk.

Bug: IMPALA-1471

Row Count Mismatch: Partition pruning with NULL

A query against a partitioned table could return incorrect results if the WHERE clause compared the partition key to NULL using operators such as = or !=.

Bug: IMPALA-1535

Fetch column stats in bulk using new (Hive .13) HMS APIs

The performance of the COMPUTE STATS statement and queries was improved, particularly for wide tables.

Bug: IMPALA-1120

Issues Fixed in Impala 2.0.2

This section lists the most significant issues fixed in Impala 2.0.2.

For the full list of fixed issues in Impala 2.0.2, see this report in the Impala JIRA tracker.

GROUP BY on STRING column produces inconsistent results

Some operations in queries submitted through Hue or other HiveServer2 clients could produce inconsistent results.

Bug: IMPALA-1453

Fix leaked file descriptor and excessive file descriptor use

Impala could encounter an error from running out of file descriptors. The fix reduces the amount of time file descriptors are kept open, and avoids leaking file descriptors when read operations encounter errors.

unix_timestamp() does not return correct time

The unix_timestamp() function could return a constant value 1 instead of a representation of the time.

Bug: IMPALA-1623

Impala should randomly select cached replica

To avoid putting too heavy a load on any one node, Impala now randomizes which scan node processes each HDFS data block rather than choosing the first cached block replica.

Bug: IMPALA-1586

Impala does not always give short name to Llama.

In clusters secured by Kerberos or LDAP, a discrepancy in internal transmission of user names could cause a communication error with Llama.

Bug: IMPALA-1606

accept unmangled native UDF symbols

The CREATE FUNCTION statement could report that it could not find a function entry point within the .so file for a UDF written in C++, even if the corresponding function was present.

Bug: IMPALA-1475

Issues Fixed in Impala 2.0.1

This section lists the most significant issues fixed in Impala 2.0.1.

For the full list of fixed issues in Impala 2.0.1, see this report in the Impala JIRA tracker.

Queries fail with metastore exception after upgrade and compute stats

After running the COMPUTE STATS statement on an Impala table, subsequent queries on that table could fail with the exception message Failed to load metadata for table: default.stats_test.

Bug: https://issues.apache.org/jira/browse/IMPALA-1416 IMPALA-1416

Workaround: Upgrading to a level of that includes the fix for HIVE-8627, prevents the problem from affecting future COMPUTE STATS statements. On affected levels of , or for Impala tables that have become inaccessible, the workaround is to disable the hive.metastore.try.direct.sql setting in the Hive metastore hive-site.xml file and issue the INVALIDATE METADATA statement for the affected table. You do not need to rerun the COMPUTE STATS statement for the table.

Issues Fixed in Impala 2.0.0

This section lists the most significant issues fixed in Impala 2.0.0.

For the full list of fixed issues in Impala 2.0.0, see this report in the Impala JIRA tracker.

Join Hint is dropped when used inside a view

Hints specified within a view query did not take effect when the view was queried, leading to slow performance. As part of this fix, Impala now supports hints embedded within comments.

Bug: IMPALA-995"

WHERE condition ignored in simple query with RIGHT JOIN

Potential wrong results for some types of queries.

Bug: IMPALA-1101"

Query with self joined table may produce incorrect results

Potential wrong results for some types of queries.

Bug: IMPALA-1102"

Incorrect plan after reordering predicates (inner join following outer join)

Potential wrong results for some types of queries.

Bug: IMPALA-1118"

Combining fragments with compatible data partitions can lead to incorrect results due to type incompatibilities (missing casts).

Potential wrong results for some types of queries.

Bug: IMPALA-1123"

Predicate dropped: Inline view + DISTINCT aggregate in outer query

Potential wrong results for some types of queries.

Bug: IMPALA-1165"

Reuse of a column in JOIN predicate may lead to incorrect results

Potential wrong results for some types of queries.

Bug: IMPALA-1353"

Usage of TRUNC with string timestamp reliably crashes node

Serious error for certain combinations of function calls and data types.

Bug: IMPALA-1105"

Timestamp Cast Returns invalid TIMESTAMP

Serious error for certain combinations of function calls and data types.

Bug: IMPALA-1109"

IllegalStateException upon JOIN of DECIMAL columns with different precision

DECIMAL columns with different precision could not be compared in join predicates.

Bug: IMPALA-1121"

Allow creating Avro tables without column definitions. Allow COMPUTE STATS to always work on Impala-created Avro tables.

Hive-created Avro tables with columns specified by a JSON file or literal could produce errors when queried in Impala, and could not be used with the COMPUTE STATS statement. Now you can create such tables in Impala to avoid such errors.

Bug: IMPALA-1104"

Ensure all webserver output is escaped

The Impala debug web UI did not properly encode all output.

Bug: IMPALA-1133"

Queries with union in inline view have empty resource requests

Certain queries could run without obeying the limits imposed by resource management.

Bug: IMPALA-1236"

Impala does not employ ACLs when checking path permissions for LOAD and INSERT

Certain INSERT and LOAD DATA statements could fail unnecessarily, if the target directories in HDFS had restrictive HDFS permissions, but those permissions were overridden by HDFS extended ACLs.

Bug: IMPALA-1279"

Impala does not map principals to lowercase, affecting Sentry authorisation

In a Kerberos environment, the principal name was not mapped to lowercase, causing issues when a user logged in with an uppercase principal name and Sentry authorization was enabled.

Bug: IMPALA-1334"

Issues Fixed in Impala 1.4.4

Issues Fixed in Impala 1.4.3

Impala 1.4.3 includes fixes to address what is known as the POODLE vulnerability in SSLv3. SSLv3 access is disabled in the Impala debug web UI.

Issues Fixed in Impala 1.4.2

This section lists the most significant issues fixed in Impala 1.4.2.

For the full list of fixed issues in Impala 1.4.2, see this report in the Impala JIRA tracker.

Issues Fixed in Impala 1.4.1

This section lists the most significant issues fixed in Impala 1.4.1.

For the full list of fixed issues in Impala 1.4.1, see this report in the Impala JIRA tracker.

impalad terminating with Boost exception

Occasionally, a non-trivial query run through Llama could encounter a serious error. The detailed error in the log was:

boost::exception_detail::clone_impl
  <boost::exception_detail::error_info_injector<boost::lock_error> >

Severity: High

Impalad uses wrong string format when writing logs

Impala log files could contain internal error messages due to a problem formatting certain strings. The messages consisted of a Java call stack starting with:

jni-util.cc:177] java.util.MissingFormatArgumentException: Format specifier 's'

Update HS2 client API.

A downlevel version of the HiveServer2 API could cause difficulty retrieving the precision and scale of a DECIMAL value.

Bug: IMPALA-1107

Impalad catalog updates can fail with error: "IllegalArgumentException: fromKey out of range"

The error in the title could occur following a DDL statement. This issue was discovered during internal testing and has not been reported in customer environments.

Bug: IMPALA-1093

"Total" time counter does not capture all the network transmit time

The time for some network operations was not counted in the report of total time for a query, making it difficult to diagnose network-related performance issues.

Bug: IMPALA-1131

Impala will crash when reading certain Avro files containing bytes data

Certain Avro fields for byte data could cause Impala to be unable to read an Avro data file, even if the field was not part of the Impala table definition. With this fix, Impala can now read these Avro data files, although Impala queries cannot refer to the "bytes" fields.

Bug: IMPALA-1149

Support specifying a custom AuthorizationProvider in Impala

The --authorization_policy_provider_class option for impalad was added back. This option specifies a custom AuthorizationProvider class rather than the default HadoopGroupAuthorizationProvider. It had been used for internal testing, then removed in Impala 1.4.0, but it was considered useful by some customers.

Bug: IMPALA-1142

Issues Fixed in Impala 1.4.0

This section lists the most significant issues fixed in Impala 1.4.0.

For the full list of fixed issues in Impala 1.4.0, see this report in the Impala JIRA tracker.

Failed DCHECK in disk-io-mgr-reader-context.cc:174

The serious error in the title could occur, with the supplemental message:

num_used_buffers_ < 0: #used=-1 during cancellation HDFS cached data

The issue was due to the use of HDFS caching with data files accessed by Impala. Support for HDFS caching in Impala was introduced in Impala 1.4.0. The fix for this issue was backported to Impala 1.3.x, and is the only change in Impala 1.3.2.

Bug: IMPALA-1019

Resolution: This issue is fixed in Impala 1.3.2. The addition of HDFS caching support in Impala 1.4 means that this issue does not apply to any new level of Impala.

impala-shell only works with ASCII characters

The impala-shell interpreter could encounter errors processing SQL statements containing non-ASCII characters.

Bug: IMPALA-489

The extended view definition SQL text in Views created by Impala should always have fully-qualified table names

When a view was accessed while inside a different database, references to tables were not resolved unless the names were fully qualified when the view was created.

Bug: IMPALA-962

Impala forgets about partitions with non-existant locations

If an ALTER TABLE specified a non-existent HDFS location for a partition, afterwards Impala would not be able to access the partition at all.

Bug: IMPALA-741

CREATE TABLE LIKE fails if source is a view

The CREATE TABLE LIKE clause was enhanced to be able to create a table with the same column definitions as a view. The resulting table is a text table unless the STORED AS clause is specified, because a view does not have an associated file format to inherit.

Bug: IMPALA-834

Improve partition pruning time

Operations on tables with many partitions could be slow due to the time to evaluate which partitions were affected. The partition pruning code was speeded up substantially.

Bug: IMPALA-887

Improve compute stats performance

The performance of the COMPUTE STATS statement was improved substantially. The efficiency of its internal operations was improved, and some statistics are no longer gathered because they are not currently used for planning Impala queries.

Bug: IMPALA-1003

When I run CREATE TABLE new_table LIKE avro_table, the schema does not get mapped properly from an avro schema to a hive schema

After a CREATE TABLE LIKE statement using an Avro table as the source, the new table could have incorrect metadata and be inaccessible, depending on how the original Avro table was created.

Bug: IMPALA-185

Race condition in IoMgr. Blocked ranges enqueued after cancel.

Impala could encounter a serious error after a query was cancelled.

Bug: IMPALA-1046

Deadlock in scan node

A deadlock condition could make all impalad daemons hang, making the cluster unresponsive for Impala queries.

Bug: IMPALA-1083

Issues Fixed in Impala 1.3.3

Impala 1.3.3 includes fixes to address what is known as the POODLE vulnerability in SSLv3. SSLv3 access is disabled in the Impala debug web UI.

Issues Fixed in Impala 1.3.2

This backported bug fix is the only change between Impala 1.3.1 and Impala 1.3.2.

Failed DCHECK in disk-io-mgr-reader-context.cc:174

The serious error in the title could occur, with the supplemental message:

num_used_buffers_ < 0: #used=-1 during cancellation HDFS cached data

The issue was due to the use of HDFS caching with data files accessed by Impala. Support for HDFS caching in Impala was introduced in Impala 1.4.0. The fix for this issue was backported to Impala 1.3.x, and is the only change in Impala 1.3.2.

Bug: IMPALA-1019

Resolution: This issue is fixed in Impala 1.3.2. The addition of HDFS caching support in Impala 1.4 means that this issue does not apply to any new level of Impala.

Issues Fixed in Impala 1.3.1

This section lists the most significant issues fixed in Impala 1.3.1.

For the full list of fixed issues in Impala 1.3.1, see this report in the Impala JIRA tracker.

Impalad crashes when left joining inline view that has aggregate using distinct

Impala could encounter a severe error in a query combining a left outer join with an inline view containing a COUNT(DISTINCT) operation.

Bug: IMPALA-904

Incorrect result with group by query with null value in group by data

If the result of a GROUP BY operation is NULL, the resulting row might be omitted from the result set. This issue depends on the data values and data types in the table.

Bug: IMPALA-901

Drop Function does not clear local library cache

When a UDF is dropped through the DROP FUNCTION statement, and then the UDF is re-created with a new .so library or JAR file, the original version of the UDF is still used when the UDF is called from queries.

Bug: IMPALA-786

Workaround: Restart the impalad daemon on all nodes.

Compute stats doesn't propagate underlying error correctly

If a COMPUTE STATS statement encountered an error, the error message is "Query aborted" with no further detail. Common reasons why a COMPUTE STATS statement might fail include network errors causing the coordinator node to lose contact with other impalad instances, and column names that match Impala reserved words. (Currently, if a column name is an Impala reserved word, COMPUTE STATS always returns an error.)

Bug: IMPALA-762

Inserts should respect changes in partition location

After an ALTER TABLE statement that changes the LOCATION property of a partition, a subsequent INSERT statement would always use a path derived from the base data directory for the table.

Bug: IMPALA-624

Text data with carriage returns generates wrong results for count(*)

A COUNT(*) operation could return the wrong result for text tables using nul characters (ASCII value 0) as delimiters.

Bug: IMPALA-13

Workaround: Impala adds support for ASCII 0 characters as delimiters through the clause FIELDS TERMINATED BY '\0'.

IO Mgr should take instance memory limit into account when creating io buffers

Impala could allocate more memory than necessary during certain operations.

Bug: IMPALA-488

Workaround: Before issuing a COMPUTE STATS statement for a Parquet table, reduce the number of threads used in that operation by issuing SET NUM_SCANNER_THREADS=2 in impala-shell. Then issue UNSET NUM_SCANNER_THREADS before continuing with queries.

Impala should provide an option for new sub directories to automatically inherit the permissions of the parent directory

When new subdirectories are created underneath a partitioned table by an INSERT statement, previously the new subdirectories always used the default HDFS permissions for the impala user, which might not be suitable for directories intended to be read and written by other components also.

Bug: IMPALA-827

Resolution: In Impala 1.3.1 and higher, you can specify the --insert_inherit_permissions configuration when starting the impalad daemon.

Illegal state exception (or crash) in query with UNION in inline view

Impala could encounter a severe error in a query where the FROM list contains an inline view that includes a UNION. The exact type of the error varies.

Bug: IMPALA-888

INSERT column reordering doesn't work with SELECT clause

The ability to specify a subset of columns in an INSERT statement, with order different than in the target table, was not working as intended.

Bug: IMPALA-945

Issues Fixed in Impala 1.3.0

This section lists the most significant issues fixed in Impala 1.3.0, primarily issues that could cause wrong results, or cause problems running the COMPUTE STATS statement, which is very important for performance and scalability.

For the full list of fixed issues, see this report in the Impala JIRA tracker.

Inner join after right join may produce wrong results

The automatic join reordering optimization could incorrectly reorder queries with an outer join or semi join followed by an inner join, producing incorrect results.

Bug: IMPALA-860

Workaround: Including the STRAIGHT_JOIN keyword in the query prevented the issue from occurring.

Incorrect results with codegen on multi-column group by with NULLs.

A query with a GROUP BY clause referencing multiple columns could introduce incorrect NULL values in some columns of the result set. The incorrect NULL values could appear in rows where a different GROUP BY column actually did return NULL.

Bug: IMPALA-850

Using distinct inside aggregate function may cause incorrect result when using having clause

A query could return incorrect results if it combined an aggregate function call, a DISTINCT operator, and a HAVING clause, without a GROUP BY clause.

Bug: IMPALA-845

Aggregation on union inside (inline) view not distributed properly.

An aggregation query or a query with ORDER BY and LIMIT could be executed on a single node in some cases, rather than distributed across the cluster. This issue affected queries whose FROM clause referenced an inline view containing a UNION.

Bug: IMPALA-831

Wrong expression may be used in aggregate query if there are multiple similar expressions

If a GROUP BY query referenced the same columns multiple times using different operators, result rows could contain multiple copies of the same expression.

Bug: IMPALA-817

Incorrect results when changing the order of aggregates in the select list with codegen enabled

Referencing the same columns in both a COUNT() and a SUM() call in the same query, or some other combinations of aggregate function calls, could incorrectly return a result of 0 from one of the aggregate functions. This issue affected references to TINYINT and SMALLINT columns, but not INT or BIGINT columns.

Bug: IMPALA-765

Workaround: Setting the query option DISABLE_CODEGEN=TRUE prevented the incorrect results. Switching the order of the function calls could also prevent the issue from occurring.

Union queries give Wrong result in a UNION followed by SIGSEGV in another union

A UNION query could produce a wrong result, followed by a serious error for a subsequent UNION query.

Bug: IMPALA-723

String data in MR-produced parquet files may be read incorrectly

Impala could return incorrect string results when reading uncompressed Parquet data files containing multiple row groups. This issue only affected Parquet data files produced by MapReduce jobs.

Bug: IMPALA-729

Compute stats need to use quotes with identifiers that are Impala keywords

Using a column or table name that conflicted with Impala keywords could prevent running the COMPUTE STATS statement for the table.

Bug: IMPALA-777

COMPUTE STATS child queries do not inherit parent query options.

The COMPUTE STATS statement did not use the setting of the MEM_LIMIT query option in impala-shell, potentially causing problems gathering statistics for wide Parquet tables.

Bug: IMPALA-903

COMPUTE STATS should update partitions in batches

The COMPUTE STATS statement could be slow or encounter a timeout while analyzing a table with many partitions.

Bug: IMPALA-880

Fail early (in analysis) when COMPUTE STATS is run against Avro table with no columns

If the columns for an Avro table were all defined in the TBLPROPERTIES or SERDEPROPERTIES clauses, the COMPUTE STATS statement would fail after completely analyzing the table, potentially causing a long delay. Although the COMPUTE STATS statement still does not work for such tables, now the problem is detected and reported immediately.

Bug: IMPALA-867

Workaround: Re-create the Avro table with columns defined in SQL style, using the output of SHOW CREATE TABLE. (See the JIRA page for detailed steps.)

Issues Fixed in the 1.2.4 Release

This section lists the most significant issues fixed in Impala 1.2.4. For the full list of fixed issues, see this report in the Impala JIRA tracker.

The Catalog Server exits with an OOM error after a certain number of CREATE statements

A large number of concurrent CREATE TABLE statements can cause the catalogd process to consume excessive memory, and potentially be killed due to an out-of-memory condition.

Bug: IMPALA-818

Workaround: Restart the catalogd service and re-try the DDL operations that failed.

Catalog Server consumes excessive cpu cycle

A large number of tables and partitions could result in unnecessary CPU overhead during Impala idle time and background operations.

Bug: IMPALA-821

Resolution: Catalog server processing was optimized in several ways.

Query against Avro table crashes Impala with codegen enabled

A query against a TIMESTAMP column in an Avro table could encounter a serious issue.

Bug: IMPALA-828

Workaround: Set the query option DISABLE_CODEGEN=TRUE

Statestore seems to send concurrent heartbeats to the same subscriber leading to repeated "Subscriber 'hostname' is registering with statestore, ignoring update" messages

Impala nodes could produce repeated error messages after recovering from a communication error with the statestore service.

Bug: IMPALA-809

Join predicate incorrectly ignored

A join query could produce wrong results if multiple equality comparisons between the same tables referred to the same column.

Bug: IMPALA-805

Query result differing between Impala and Hive

Certain outer join queries could return wrong results. If one of the tables involved in the join was an inline view, some tests from the WHERE clauses could be applied to the wrong phase of the query.

ArrayIndexOutOfBoundsException / Invalid query handle when reading large HBase cell

An HBase cell could contain a value larger than 32 KB, leading to a serious error when Impala queries that table. The error could occur even if the applicable row is not part of the result set.

Bug: IMPALA-715

Workaround: Use smaller values in the HBase table, or exclude the column containing the large value from the result set.

select with distinct and full outer join, impalad coredump

A query involving a DISTINCT operator combined with a FULL OUTER JOIN could encounter a serious error.

Bug: IMPALA-735

Workaround: Set the query option DISABLE_CODEGEN=TRUE

Impala cannot load tables with more than Short.MAX_VALUE number of partitions

If a table had more than 32,767 partitions, Impala would not recognize the partitions above the 32K limit and query results could be incomplete.

Bug: IMPALA-749

Various issues with HBase row key specification

Queries against HBase tables could fail with an error if the row key was compared to a function return value rather than a string constant. Also, queries against HBase tables could fail if the WHERE clause contained combinations of comparisons that could not possibly match any row key.

Resolution: Queries now return appropriate results when function calls are used in the row key comparison. For queries involving non-existent row keys, such as WHERE row_key IS NULL or where the lower bound is greater than the upper bound, the query succeeds and returns an empty result set.

Issues Fixed in the 1.2.3 Release

This release is a fix release that supercedes Impala 1.2.2, with the same features and fixes as 1.2.2 plus one additional fix for compatibility with Parquet files generated outside of Impala by components such as Hive, Pig, or MapReduce.

Impala cannot read Parquet files with multiple row groups

An early version of the parquet-mr library writes files that are not readable by Impala, due to the presence of multiple row groups. Queries involving these data files might result in a crash or a failure with an error such as "Column chunk should not contain two dictionary pages".

This issue does not occur for Parquet files produced by Impala INSERT statements, because Impala only produces files with a single row group.

Bug: IMPALA-720

Issues Fixed in the 1.2.2 Release

This section lists the most significant issues fixed in Impala 1.2.2. For the full list of fixed issues, see this report in the Impala JIRA tracker.

Order of table references in FROM clause is critical for optimal performance

Impala does not currently optimize the join order of queries; instead, it joins tables in the order in which they are listed in the FROM clause. Queries that contain one or more large tables on the right hand side of joins (either an explicit join expressed as a JOIN statement or a join implicit in the list of table references in the FROM clause) may run slowly or crash Impala due to out-of-memory errors. For example:

SELECT ... FROM small_table JOIN large_table

Anticipated Resolution: Fixed in Impala 1.2.2.

Workaround: In Impala 1.2.2 and higher, use the COMPUTE STATS statement to gather statistics for each table involved in the join query, after data is loaded. Prior to Impala 1.2.2, modify the query, if possible, to join the largest table first. For example:

SELECT ... FROM small_table JOIN large_table

should be modified to:

SELECT ... FROM large_table JOIN small_table

Parquet in CDH4.5 writes data files that are sometimes unreadable by Impala

Some Parquet files could be generated by other components that Impala could not read.

Bug: IMPALA-694

Resolution: The underlying issue is being addressed by a fix in the Parquet libraries. Impala 1.2.2 works around the problem and reads the existing data files.

Deadlock in statestore when unregistering a subscriber and building a topic update

The statestore service cound experience an internal error leading to a hang.

Bug: IMPALA-699

IllegalStateException when doing a union involving a group by

A UNION query where one side involved a GROUP BY operation could cause a serious error.

Bug: IMPALA-687

Impala Parquet Writer hit DCHECK in RleEncoder

A serious error could occur when doing an INSERT into a Parquet table.

Bug: IMPALA-689

Hive UDF jars cannot be loaded by the FE

If the JAR file for a Java-based Hive UDF was not in the CLASSPATH, the UDF could not be called during a query.

Bug: IMPALA-695

Issues Fixed in the 1.2.1 Release

This section lists the most significant issues fixed in Impala 1.2.1. For the full list of fixed issues, see this report in the Impala JIRA tracker.

Scanners use too much memory when reading past scan range

While querying a table with long column values, Impala could over-allocate memory leading to an out-of-memory error. This problem was observed most frequently with tables using uncompressed RCFile or text data files.

Bug: IMPALA-525

Resolution: Fixed in 1.2.1

Join node consumes memory way beyond mem-limit

A join query could allocate a temporary work area that was larger than needed, leading to an out-of-memory error. The fix makes Impala return unused memory to the system when the memory limit is reached, avoiding unnecessary memory errors.

Bug: IMPALA-657

Resolution: Fixed in 1.2.1

Excessive memory consumption when query tables with 1k columns (Parquet file)

Impala could encounter an out-of-memory condition setting up work areas for Parquet tables with many columns. The fix reduces the size of the allocated memory when not actually needed to hold table data.

Bug: IMPALA-652

Resolution: Fixed in 1.2.1

Issues Fixed in the 1.2.0 Beta Release

This section lists the most significant issues fixed in Impala 1.2 (beta). For the full list of fixed issues, see this report in the Impala JIRA tracker.

Issues Fixed in the 1.1.1 Release

This section lists the most significant issues fixed in Impala 1.1.1. For the full list of fixed issues, see this report in the Impala JIRA tracker.

Unexpected LLVM Crash When Querying Doubles on CentOS 5.x

Certain queries involving DOUBLE columns could fail with a serious error. The fix improves the generation of native machine instructions for certain chipsets.

Bug: IMPALA-477

"block size is too big" error with Snappy-compressed RCFile containing null

Queries could fail with a "block size is too big" error, due to NULL values in RCFile tables using Snappy compression.

Bug: IMPALA-482

Cannot query RC file for table that has more columns than the data file

Queries could fail if an Impala RCFile table was defined with more columns than in the corresponding RCFile data files.

Bug: IMPALA-510

Views Sometimes Not Utilizing Partition Pruning

Certain combinations of clauses in a view definition for a partitioned table could result in inefficient performance and incorrect results.

Bug: IMPALA-495

Update the serde name we write into the metastore for Parquet tables

The SerDes class string written into Parquet data files created by Impala was updated for compatibility with Parquet support in Hive. See Incompatible Changes Introduced in Impala 1.1.1 for the steps to update older Parquet data files for Hive compatibility.

Bug: IMPALA-485

Selective queries over large tables produce unnecessary memory consumption

A query returning a small result sets from a large table could tie up memory unnecessarily for the duration of the query.

Bug: IMPALA-534

Impala stopped to query AVRO tables

Queries against Avro tables could fail depending on whether the Avro schema URL was specified in the TBLPROPERTIES or SERDEPROPERTIES field. The fix causes Impala to check both fields for the schema URL.

Bug: IMPALA-538

Impala continues to allocate more memory even though it has exceed its mem-limit

Queries could allocate substantially more memory than specified in the impalad -mem_limit startup option. The fix causes more frequent checking of the limit during query execution.

Bug: IMPALA-520

Issues Fixed in the 1.1.0 Release

This section lists the most significant issues fixed in Impala 1.1. For the full list of fixed issues, see this report in the Impala JIRA tracker.

10-20% perf regression for most queries across all table formats

This issue is due to a performance tradeoff between systems running many queries concurrently, and systems running a single query. Systems running only a single query could experience lower performance than in early beta releases. Systems running many queries simultaneously should experience higher performance than in the beta releases.

planner fails with "Join requires at least one equality predicate between the two tables" when "from" table order does not match "where" join order

A query could fail if it involved 3 or more tables and the last join table was specified as a subquery.

Bug: IMPALA-85

Parquet writer uses excessive memory with partitions

INSERT statements against partitioned tables using the Parquet format could use excessive amounts of memory as the number of partitions grew large.

Bug: IMPALA-257

Comments in impala-shell in interactive mode are not handled properly causing syntax errors or wrong results

The impala-shell interpreter did not accept comment entered at the command line, making it problematic to copy and paste from scripts or other code examples.

Bug: IMPALA-192

Cancelled queries sometimes aren't removed from the inflight query list

The Impala web UI would sometimes display a query as if it were still running, after the query was cancelled.

Bug: IMPALA-364

Impala's 1.0.1 Shell Broke Python 2.4 Compatibility (AttributeError: 'module' object has no attribute 'field_size_limit)

The impala-shell command in Impala 1.0.1 does not work with Python 2.4, which is the default on Red Hat 5.

For the impala-shell command in Impala 1.0, the -o option (pipe output to a file) does not work with Python 2.4.

Bug: IMPALA-396

Issues Fixed in the 1.0.1 Release

This section lists the most significant issues fixed in Impala 1.0.1. For the full list of fixed issues, see this report in the Impala JIRA tracker.

Impala parquet scanner cannot read all data files generated by other frameworks

Impala might issue an erroneous error message when processing a Parquet data file produced by a non-Impala Hadoop component.

Bug: IMPALA-333

Resolution: Fixed

Impala is unable to query RCFile tables which describe fewer columns than the file's header.

If an RCFile table definition had fewer columns than the fields actually in the data files, queries would fail.

Bug: IMPALA-293

Resolution: Fixed

Impala does not correctly substitute _HOST with hostname in --principal

The _HOST placeholder in the --principal startup option was not substituted with the correct hostname, potentially leading to a startup error in setups using Kerberos authentication.

Bug: IMPALA-351

Resolution: Fixed

HBase query missed the last region

A query for an HBase table could omit data from the last region.

Bug: IMPALA-356

Resolution: Fixed

Hbase region changes are not handled correctly

After a region in an HBase table was split or moved, an Impala query might return incomplete or out-of-date results.

Bug: IMPALA-300

Resolution: Fixed

Query state for successful create table is EXCEPTION

After a successful CREATE TABLE statement, the corresponding query state would be incorrectly reported as EXCEPTION.

Bug: IMPALA-349

Resolution: Fixed

Double check release of JNI-allocated byte-strings

Operations involving calls to the Java JNI subsystem (for example, queries on HBase tables) could allocate memory but not release it.

Bug: IMPALA-358

Resolution: Fixed

Impala returns 0 for bad time values in UNIX_TIMESTAMP, Hive returns NULL

Impala returns 0 for bad time values in UNIX_TIMESTAMP, Hive returns NULL.

Impala:

impala> select UNIX_TIMESTAMP('10:02:01') ;
impala> 0

Hive:

hive> select UNIX_TIMESTAMP('10:02:01') FROM tmp;
hive> NULL

Bug: IMPALA-16

Anticipated Resolution: Fixed

INSERT INTO TABLE SELECT <constant> does not work.

Insert INTO TABLE SELECT <constant> will not insert any data and may return an error.

Anticipated Resolution: Fixed

Issues Fixed in the 1.0 GA Release

Here are the major user-visible issues fixed in Impala 1.0. For a full list of fixed issues, see this report in the Impala JIRA tracker.

Undeterministically receive "ERROR: unknown row bach destination..." and "ERROR: Invalid query handle" from impala shell when running union query

A query containing both UNION and LIMIT clauses could intermittently cause the impalad process to halt with a segmentation fault.

Bug: IMPALA-183

Resolution: Fixed

Insert with NULL partition keys results in SIGSEGV.

An INSERT statement specifying a NULL value for one of the partitioning columns could cause the impalad process to halt with a segmentation fault.

Bug: IMPALA-190

Resolution: Fixed

INSERT queries don't show completed profiles on the debug webpage

In the Impala web user interface, the profile page for an INSERT statement showed obsolete information for the statement once it was complete.

Bug: IMPALA-217

Resolution: Fixed

Impala HBase scan is very slow

Queries involving an HBase table could be slower than expected, due to excessive memory usage on the Impala nodes.

Bug: IMPALA-231

Resolution: Fixed

Add some library version validation logic to impalad when loading impala-lzo shared library

No validation was done to check that the impala-lzo shared library was compatible with the version of Impala, possibly leading to a crash when using LZO-compressed text files.

Bug: IMPALA-234

Resolution: Fixed

Workaround: Always upgrade the impala-lzo library at the same time as you upgrade Impala itself.

Problems inserting into tables with TIMESTAMP partition columns leading table metadata loading failures and failed dchecks

INSERT statements for tables partitioned on columns involving datetime types could appear to succeed, but cause errors for subsequent queries on those tables. The problem was especially serious if an improperly formatted timestamp value was specified for the partition key.

Bug: IMPALA-238

Resolution: Fixed

Ctrl-C sometimes interrupts shell in system call, rather than cancelling query

Pressing Ctrl-C in the impala-shell interpreter could sometimes display an error and return control to the shell, making it impossible to cancel the query.

Bug: IMPALA-243

Resolution: Fixed

Empty string partition value causes metastore update failure

Specifying an empty string or NULL for a partition key in an INSERT statement would fail.

Bug: IMPALA-252

Resolution: Fixed. The behavior for empty partition keys was made more compatible with the corresponding Hive behavior.

Round() does not output the right precision

The round() function did not always return the correct number of significant digits.

Bug: IMPALA-266

Resolution: Fixed

Cannot cast string literal to string

Casting from a string literal back to the same type would cause an "invalid type cast" error rather than leaving the original value unchanged.

Bug: IMPALA-267

Resolution: Fixed

Excessive mem usage for certain queries which are very selective

Some queries that returned very few rows experienced unnecessary memory usage.

Bug: IMPALA-288

Resolution: Fixed

HdfsScanNode crashes in UpdateCounters

A serious error could occur for relatively small and inexpensive queries.

Bug: IMPALA-289

Resolution: Fixed

Parquet performance issues on large dataset

Certain aggregation queries against Parquet tables were inefficient due to lower than required thread utilization.

Bug: IMPALA-292

Resolution: Fixed

impala not populating hive metadata correctly for create table

The Impala CREATE TABLE command did not fill in the owner and tbl_type columns in the Hive metastore database.

Bug: IMPALA-295

Resolution: Fixed. The metadata was made more Hive-compatible.

impala daemons die if statestore goes down

The impalad instances in a cluster could halt when the statestored process became unavailable.

Bug: IMPALA-312

Resolution: Fixed

Constant SELECT clauses do not work in subqueries

A subquery would fail if the SELECT statement inside it returned a constant value rather than querying a table.

Bug: IMPALA-67

Resolution: Fixed

Right outer Join includes NULLs as well and hence wrong result count

The result set from a right outer join query could include erroneous rows containing NULL values.

Bug: IMPALA-90

Resolution: Fixed

Parquet scanner hangs for some queries

The Parquet scanner non-deterministically hangs when executing some queries.

Bug: IMPALA-204

Resolution: Fixed

Issues Fixed in Version 0.7 of the Beta Release

Impala does not gracefully handle unsupported Hive table types (INDEX and VIEW tables)

When attempting to load metadata from an unsupported Hive table type (INDEX and VIEW tables), Impala fails with an unclear error message.

Bug: IMPALA-167

Resolution: Fixed in 0.7

DDL statements (CREATE/ALTER/DROP TABLE) are not supported in the Impala Beta Release

Resolution: Fixed in 0.7

Avro is not supported in the Impala Beta Release

Resolution: Fixed in 0.7

Workaround: None

Impala does not currently allow limiting the memory consumption of a single query

It is currently not possible to limit the memory consumption of a single query. All tables on the right hand side of JOIN statements need to be able to fit in memory. If they do not, Impala may crash due to out of memory errors.

Resolution: Fixed in 0.7

Aggregate of a subquery result set returns wrong results if the subquery contains a 'limit' and data is distributed across multiple nodes

Aggregate of a subquery result set returns wrong results if the subquery contains a 'limit' clause and data is distributed across multiple nodes. From the query plan, it looks like we are just summing the results from each worker node.

Bug: IMPALA-20

Resolution: Fixed in 0.7

Partition pruning for arbitrary predicates that are fully bound by a particular partition column

We currently cannot utilize a predicate like "country_code in ('DE', 'FR', 'US')" to do partitioning pruning, because that requires an equality predicate or a binary comparison.

We should create a superclass of planner.ValueRange, ValueSet, that can be constructed with an arbitrary predicate, and whose isInRange(analyzer, valueExpr) constructs a literal predicate by substitution of the valueExpr into the predicate.

Bug: IMPALA-144

Resolution: Fixed in 0.7

Issues Fixed in Version 0.6 of the Beta Release

Impala reads the NameNode address and port as command line parameters

Impala reads the NameNode address and port as command line parameters rather than reading them from core-site.xml. Updating the NameNode address in the core-site.xml file does not propagate to Impala.

Severity: Low

Resolution: Fixed in 0.6 - Impala reads the namenode location and port from the Hadoop configuration files, though setting -nn and -nn_port overrides this. Users are advised not to set -nn or -nn_port.

Queries may fail on secure environment due to impalad Kerberos ticket expiration

Queries may fail on secure environment due to impalad Kerberos tickets expiring. This can happen if the Impala -kerberos_reinit_interval flag is set to a value ten minutes or less. This may lead to an impalad requesting a ticket with a lifetime that is less than the time to the next ticket renewal.

Bug: IMPALA-64

Resolution: Fixed in 0.6

Concurrent queries may fail when Impala uses Thrift to communicate with the Hive Metastore

Concurrent queries may fail when Impala is using Thrift to communicate with part of the Hive Metastore such as the Hive Metastore Service. In such a case, the error get_fields failed: out of sequence response" may occur because Impala shared a single Hive Metastore Client connection across threads. With Impala 0.6, a separate connection is used for each metadata request.

Bug: IMPALA-48

Resolution: Fixed in 0.6

impalad fails to start if unable to connect to the Hive Metastore

Impala fails to start if it is unable to establish a connection with the Hive Metastore. This behavior was fixed, allowing Impala to start, even when no Metastore is available.

Bug: IMPALA-58

Resolution: Fixed in 0.6

Impala treats database names as case-sensitive in some contexts

In some queries (including "USE database" statements), database names are treated as case-sensitive. This may lead queries to fail with an IllegalStateException.

Bug: IMPALA-44

Resolution: Fixed in 0.6

Impala does not ignore hidden HDFS files

Impala does not ignore hidden HDFS files, meaning those files prefixed with a period '.' or underscore '_'. This diverges from Hive/MapReduce, which skips these files.

Bug: IMPALA-18

Resolution: Fixed in 0.6

Issues Fixed in Version 0.5 of the Beta Release

Impala may have reduced performance on tables that contain a large number of partitions

Impala may have reduced performance on tables that contain a large number of partitions. This is due to extra overhead reading/parsing the partition metadata.

Resolution: Fixed in 0.5

Backend client connections not getting cached causes an observable latency in secure clusters

Backend impalads do not cache connections to the coordinator. On a secure cluster, this introduces a latency proportional to the number of backend clients involved in query execution, as the cost of establishing a secure connection is much higher than in the non-secure case.

Bug: IMPALA-38

Resolution: Fixed in 0.5

Concurrent queries may fail with error: "Table object has not been been initialised : `PARTITIONS`"

Concurrent queries may fail with error: "Table object has not been been initialised : `PARTITIONS`". This was due to a lack of locking in the Impala table/database metadata cache.

Bug: IMPALA-30

Resolution: Fixed in 0.5

UNIX_TIMESTAMP format behaviour deviates from Hive when format matches a prefix of the time value

The Impala UNIX_TIMESTAMP(val, format) operation compares the length of format and val and returns NULL if they do not match. Hive instead effectively truncates val to the length of the format parameter.

Bug: IMPALA-15

Resolution: Fixed in 0.5

Issues Fixed in Version 0.4 of the Beta Release

Impala fails to refresh the Hive metastore if a Hive temporary configuration file is removed

Impala is impacted by Hive bug HIVE-3596 which may cause metastore refreshes to fail if a Hive temporary configuration file is deleted (normally located at /tmp/hive-<user>-<tmp_number>.xml). Additionally, the impala-shell will incorrectly report that the failed metadata refresh completed successfully.

Anticipated Resolution: To be fixed in a future release

Workaround: Restart the impalad service. Use the impalad log to check for metadata refresh errors.

lpad/rpad builtin functions is not correct.

The lpad/rpad builtin functions generate the wrong results.

Resolution: Fixed in 0.4

Files with .gz extension reported as 'not supported'

Compressed files with extensions incorrectly generate an exception.

Bug: IMPALA-14

Resolution: Fixed in 0.4

Queries with large limits would hang.

Some queries with large limits were hanging.

Resolution: Fixed in 0.4

Order by on a string column produces incorrect results if there are empty strings

Resolution: Fixed in 0.4

Issues Fixed in Version 0.3 of the Beta Release

All table loading errors show as unknown table

If Impala is unable to load the metadata for a table for any reason, a subsequent query referring to that table will return an unknown table error message, even if the table is known.

Resolution: Fixed in 0.3

A table that cannot be loaded will disappear from SHOW TABLES

After failing to load metadata for a table, Impala removes that table from the list of known tables returned in SHOW TABLES. Subsequent attempts to query the table returns 'unknown table', even if the metadata for that table is fixed.

Resolution: Fixed in 0.3

Impala cannot read from HBase tables that are not created as external tables in the hive metastore.

Attempting to select from these tables fails.

Resolution: Fixed in 0.3

Certain queries that contain OUTER JOINs may return incorrect results

Queries that contain OUTER JOINs may not return the correct results if there are predicates referencing any of the joined tables in the WHERE clause.

Resolution: Fixed in 0.3.

Issues Fixed in Version 0.2 of the Beta Release

Subqueries which contain aggregates cannot be joined with other tables or Impala may crash

Subqueries that contain an aggregate cannot be joined with another table or Impala may crash. For example:

SELECT * FROM (SELECT sum(col1) FROM some_table GROUP BY col1) t1 JOIN other_table ON (...);

Resolution: Fixed in 0.2

An insert with a limit that runs as more than one query fragment inserts more rows than the limit.

For example:

INSERT OVERWRITE TABLE test SELECT * FROM test2 LIMIT 1;

Resolution: Fixed in 0.2

Query with limit clause might fail.

For example:

SELECT * FROM test2 LIMIT 1;

Resolution: Fixed in 0.2

Files in unsupported compression formats are read as plain text.

Attempting to read such files does not generate a diagnostic.

Resolution: Fixed in 0.2

Impala server raises a null pointer exception when running an HBase query.

When querying an HBase table whose row-key is string type, the Impala server may raise a null pointer exception.

Resolution: Fixed in 0.2