Hive 29574 merge join poc #6456
There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,73 @@ | ||
| /* | ||
| * Licensed to the Apache Software Foundation (ASF) under one | ||
| * or more contributor license agreements. See the NOTICE file | ||
| * distributed with this work for additional information | ||
| * regarding copyright ownership. The ASF licenses this file | ||
| * to you under the Apache License, Version 2.0 (the | ||
| * "License"); you may not use this file except in compliance | ||
| * with the License. You may obtain a copy of the License at | ||
| * | ||
| * http://www.apache.org/licenses/LICENSE-2.0 | ||
| * | ||
| * Unless required by applicable law or agreed to in writing, software | ||
| * distributed under the License is distributed on an "AS IS" BASIS, | ||
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
| * See the License for the specific language governing permissions and | ||
| * limitations under the License. | ||
| */ | ||
|
|
||
| package org.apache.hadoop.hive.ql.exec.tez.monitoring; | ||
|
|
||
| import org.apache.hadoop.hive.ql.metadata.HiveException; | ||
| import org.slf4j.Logger; | ||
| import org.slf4j.LoggerFactory; | ||
|
|
||
| public class SkewedMergeJoinMonitor { | ||
|
|
||
| private transient long mergeJoinSkewThreshold; | ||
| private transient boolean mergeJoinSkewAbort; | ||
| private transient boolean[] skewedKeyFlagged; | ||
|
|
||
| private static final Logger LOG = LoggerFactory.getLogger(SkewedMergeJoinMonitor.class.getName()); | ||
|
|
||
| public SkewedMergeJoinMonitor(long mergeJoinSkewThreshold, boolean mergeJoinSkewAbort, int maxAlias) { | ||
| this.mergeJoinSkewThreshold = mergeJoinSkewThreshold; | ||
| this.mergeJoinSkewAbort = mergeJoinSkewAbort; | ||
| skewedKeyFlagged = new boolean[maxAlias]; | ||
| } | ||
|
|
||
| public boolean isActive() { | ||
|
Contributor
There was a problem hiding this comment. can be private, or package-protected @VisibleForTesting if unit tests need it |
||
| return mergeJoinSkewThreshold > 0; | ||
| } | ||
|
|
||
| public boolean shouldBeFlagged(byte alias, long rowCount) { | ||
| return rowCount >= mergeJoinSkewThreshold && !skewedKeyFlagged[alias]; | ||
| } | ||
|
|
||
| public boolean isFlagged(int alias) { | ||
| return skewedKeyFlagged[alias]; | ||
| } | ||
|
|
||
| public void checkMergeJoinSkew(byte alias, long rowCount) throws HiveException { | ||
| if (!isActive()) { | ||
| return; | ||
| } | ||
|
|
||
| if (!shouldBeFlagged(alias, rowCount)) { | ||
| return; | ||
| } | ||
|
|
||
| skewedKeyFlagged[alias] = true; | ||
|
|
||
| String msg = String.format( | ||
| "Data skew detected in merge join, " | ||
| + "table alias %d has accumulated %d rows.", | ||
| alias, rowCount); | ||
|
|
||
| if (mergeJoinSkewAbort) { | ||
| throw new HiveException(msg); | ||
| } else { | ||
| LOG.warn(msg); | ||
| } | ||
| } | ||
| } | ||
|
Contributor
There was a problem hiding this comment. in general: in Hive, 2 spaces indentation is used |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,100 @@ | ||
| /* | ||
| * Licensed to the Apache Software Foundation (ASF) under one | ||
| * or more contributor license agreements. See the NOTICE file | ||
| * distributed with this work for additional information | ||
| * regarding copyright ownership. The ASF licenses this file | ||
| * to you under the Apache License, Version 2.0 (the | ||
| * "License"); you may not use this file except in compliance | ||
| * with the License. You may obtain a copy of the License at | ||
| * | ||
| * http://www.apache.org/licenses/LICENSE-2.0 | ||
| * | ||
| * Unless required by applicable law or agreed to in writing, software | ||
| * distributed under the License is distributed on an "AS IS" BASIS, | ||
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
| * See the License for the specific language governing permissions and | ||
| * limitations under the License. | ||
| */ | ||
|
|
||
| package org.apache.hadoop.hive.ql.exec; | ||
|
|
||
| import org.apache.hadoop.hive.ql.exec.tez.monitoring.SkewedMergeJoinMonitor; | ||
| import org.apache.hadoop.hive.ql.metadata.HiveException; | ||
| import org.junit.Assert; | ||
| import org.junit.Before; | ||
| import org.junit.Test; | ||
|
|
||
| public class TestCommonMergeJoinSkewThreshold { | ||
|
|
||
| private CommonMergeJoinOperator op; | ||
|
|
||
| @Before | ||
| public void setUp() { | ||
| op = new CommonMergeJoinOperator(); | ||
| } | ||
|
|
||
| @Test | ||
| public void testDisabled_noWarnNoThrow() throws HiveException { | ||
| op.skewedMergeJoinMonitor = new SkewedMergeJoinMonitor( | ||
| -1L, false, 4); | ||
|
|
||
| op.skewedMergeJoinMonitor.checkMergeJoinSkew((byte) 0, Long.MAX_VALUE); | ||
|
Contributor
There was a problem hiding this comment. try to assert on something that reflects the expected outcome |
||
| } | ||
|
|
||
| @Test | ||
| public void testBelowThreshold_isOk() throws HiveException { | ||
| op.skewedMergeJoinMonitor = new SkewedMergeJoinMonitor( | ||
| 1000L, false, 4); | ||
| op.skewedMergeJoinMonitor.checkMergeJoinSkew((byte) 0, 999L); | ||
|
Contributor
There was a problem hiding this comment. try to assert on something that reflects the expected outcome |
||
| } | ||
|
|
||
| @Test | ||
| public void testAtThreshold_warnOnce() throws HiveException { | ||
| op.skewedMergeJoinMonitor = new SkewedMergeJoinMonitor( | ||
| 500L, false, 4); | ||
|
|
||
| // should warn without throwing | ||
| op.skewedMergeJoinMonitor.checkMergeJoinSkew((byte) 0, 500L); | ||
|
|
||
| Assert.assertTrue("skewedKeyFlagged[0] must be set after the first crossing", | ||
| op.skewedMergeJoinMonitor.isFlagged(0)); | ||
|
|
||
|
Contributor
There was a problem hiding this comment. nit: extra line break is not needed |
||
| } | ||
|
|
||
| @Test | ||
| public void testFlagsAreIndependentPerTag() throws HiveException { | ||
| op.skewedMergeJoinMonitor = new SkewedMergeJoinMonitor( | ||
| 100L, false, 4); | ||
|
|
||
| op.skewedMergeJoinMonitor.checkMergeJoinSkew((byte) 0, 200L); | ||
| Assert.assertTrue("tag 0 should be flagged", op.skewedMergeJoinMonitor.isFlagged(0)); | ||
| Assert.assertFalse("tag 1 should still be clear", op.skewedMergeJoinMonitor.isFlagged(1)); | ||
|
|
||
| op.skewedMergeJoinMonitor.checkMergeJoinSkew((byte) 1, 150L); | ||
| Assert.assertTrue("tag 1 should now be flagged", op.skewedMergeJoinMonitor.isFlagged(1)); | ||
| } | ||
|
|
||
| @Test | ||
| public void testAbortMode_belowThreshold_noThrow() throws HiveException { | ||
| op.skewedMergeJoinMonitor = new SkewedMergeJoinMonitor( | ||
| 100L, true, 4); | ||
|
|
||
| op.skewedMergeJoinMonitor.checkMergeJoinSkew((byte) 0, 99L); | ||
|
Contributor
There was a problem hiding this comment. try to assert on something that reflects the expected outcome "below threshold" |
||
| } | ||
|
|
||
| @Test | ||
| public void testAbortMode_throwsHiveException() { | ||
| op.skewedMergeJoinMonitor = new SkewedMergeJoinMonitor( | ||
| 100L, true, 4); | ||
|
|
||
| try { | ||
| op.skewedMergeJoinMonitor.checkMergeJoinSkew((byte) 0, 200L); | ||
| Assert.fail("Expected HiveException to be thrown in abort mode"); | ||
| } catch (HiveException e) { | ||
| String msg = e.getMessage(); | ||
| Assert.assertNotNull(msg); | ||
| Assert.assertTrue("Message should mention row count 200", msg.contains("200")); | ||
| } | ||
| } | ||
| } | ||
|
|
||
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,20 @@ | ||
| SET hive.vectorized.execution.enabled=false; | ||
|
Contributor
There was a problem hiding this comment. vectorization should be enabled, we can simple delete this |
||
| set hive.mapred.mode=nonstrict; | ||
|
Contributor
There was a problem hiding this comment. is |
||
| set hive.explain.user=false; | ||
| set hive.cbo.enable=false; | ||
|
Contributor
There was a problem hiding this comment. cbo should be enabled, we can simply delete this |
||
| set hive.auto.convert.join=false; | ||
| set hive.optimize.ppd=false; | ||
|
Contributor
There was a problem hiding this comment. is |
||
| -- merge join observability config, with true should throw exception after skew | ||
| -- join detected beyond the threshold | ||
| set hive.merge.join.skew.threshold=2; | ||
| set hive.merge.join.skew.abort=true; | ||
|
|
||
| CREATE TABLE merge_skew_abort_a (key int, value string) STORED AS TEXTFILE; | ||
| CREATE TABLE merge_skew_abort_b (key int, value string) STORED AS TEXTFILE; | ||
|
Comment on lines
+12
to
+13
Contributor
There was a problem hiding this comment. remove "STORED AS TEXTFILE", we use default ORC unless there is a reason to do otherwise |
||
|
|
||
| INSERT INTO TABLE merge_skew_abort_a VALUES (1, 'a1'), (1, 'a2'), (1, 'a3'), (1, 'a4'),(2, 'b1'); | ||
| INSERT INTO TABLE merge_skew_abort_b VALUES (1, 'x1'), (2, 'y1'); | ||
|
|
||
| SELECT a.key, a.value, b.value | ||
| FROM merge_skew_abort_a a JOIN merge_skew_abort_b b ON a.key = b.key; | ||
|
|
||
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,35 @@ | ||
| SET hive.vectorized.execution.enabled=false; | ||
|
Contributor
There was a problem hiding this comment. vectorization should be enabled, we can simple delete this |
||
| set hive.mapred.mode=nonstrict; | ||
|
Contributor
There was a problem hiding this comment. is |
||
| set hive.explain.user=false; | ||
| set hive.cbo.enable=false; | ||
|
Contributor
There was a problem hiding this comment. cbo should be enabled, we can simply delete this |
||
| set hive.auto.convert.join=false; | ||
| set hive.optimize.ppd=false; | ||
|
Contributor
There was a problem hiding this comment. is |
||
| set hive.merge.join.skew.threshold=2; | ||
| set hive.merge.join.skew.abort=false; | ||
|
|
||
| -- SORT_QUERY_RESULTS | ||
|
|
||
| CREATE TABLE merge_skew_warn_a (key int, value string) STORED AS TEXTFILE; | ||
| CREATE TABLE merge_skew_warn_b (key int, value string) STORED AS TEXTFILE; | ||
|
Comment on lines
+12
to
+13
Contributor
There was a problem hiding this comment. remove "STORED AS TEXTFILE", we use default ORC unless there is a reason to do otherwise |
||
|
|
||
| INSERT INTO TABLE merge_skew_warn_a VALUES (1, 'a1'), (1, 'a2'), (1, 'a3'), (1, 'a4'), | ||
| (2, 'b1'), (3, 'c1'); | ||
| INSERT INTO TABLE merge_skew_warn_b VALUES (1, 'x1'), (2, 'y1'), (3, 'z1'); | ||
|
|
||
| EXPLAIN | ||
| SELECT a.key, a.value, b.value | ||
| FROM merge_skew_warn_a a JOIN merge_skew_warn_b b ON a.key = b.key; | ||
|
|
||
| SELECT a.key, a.value, b.value | ||
| FROM merge_skew_warn_a a JOIN merge_skew_warn_b b ON a.key = b.key; | ||
|
|
||
| SELECT count(*) FROM merge_skew_warn_a a JOIN merge_skew_warn_b b ON a.key = b.key; | ||
|
|
||
| -- no warning run | ||
| set hive.merge.join.skew.threshold=-1; | ||
|
|
||
| SELECT count(*) FROM merge_skew_warn_a a JOIN merge_skew_warn_b b ON a.key = b.key; | ||
|
|
||
| DROP TABLE merge_skew_warn_a; | ||
| DROP TABLE merge_skew_warn_b; | ||
|
|
||
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,70 @@ | ||
| PREHOOK: query: CREATE TABLE merge_skew_abort_a (key int, value string) STORED AS TEXTFILE | ||
| PREHOOK: type: CREATETABLE | ||
| PREHOOK: Output: database:default | ||
| PREHOOK: Output: default@merge_skew_abort_a | ||
| POSTHOOK: query: CREATE TABLE merge_skew_abort_a (key int, value string) STORED AS TEXTFILE | ||
| POSTHOOK: type: CREATETABLE | ||
| POSTHOOK: Output: database:default | ||
| POSTHOOK: Output: default@merge_skew_abort_a | ||
| PREHOOK: query: CREATE TABLE merge_skew_abort_b (key int, value string) STORED AS TEXTFILE | ||
| PREHOOK: type: CREATETABLE | ||
| PREHOOK: Output: database:default | ||
| PREHOOK: Output: default@merge_skew_abort_b | ||
| POSTHOOK: query: CREATE TABLE merge_skew_abort_b (key int, value string) STORED AS TEXTFILE | ||
| POSTHOOK: type: CREATETABLE | ||
| POSTHOOK: Output: database:default | ||
| POSTHOOK: Output: default@merge_skew_abort_b | ||
| PREHOOK: query: INSERT INTO TABLE merge_skew_abort_a VALUES (1, 'a1'), (1, 'a2'), (1, 'a3'), (1, 'a4'),(2, 'b1') | ||
| PREHOOK: type: QUERY | ||
| PREHOOK: Input: _dummy_database@_dummy_table | ||
| PREHOOK: Output: default@merge_skew_abort_a | ||
| POSTHOOK: query: INSERT INTO TABLE merge_skew_abort_a VALUES (1, 'a1'), (1, 'a2'), (1, 'a3'), (1, 'a4'),(2, 'b1') | ||
| POSTHOOK: type: QUERY | ||
| POSTHOOK: Input: _dummy_database@_dummy_table | ||
| POSTHOOK: Output: default@merge_skew_abort_a | ||
| POSTHOOK: Lineage: merge_skew_abort_a.key SCRIPT [] | ||
| POSTHOOK: Lineage: merge_skew_abort_a.value SCRIPT [] | ||
| PREHOOK: query: INSERT INTO TABLE merge_skew_abort_b VALUES (1, 'x1'), (2, 'y1') | ||
| PREHOOK: type: QUERY | ||
| PREHOOK: Input: _dummy_database@_dummy_table | ||
| PREHOOK: Output: default@merge_skew_abort_b | ||
| POSTHOOK: query: INSERT INTO TABLE merge_skew_abort_b VALUES (1, 'x1'), (2, 'y1') | ||
| POSTHOOK: type: QUERY | ||
| POSTHOOK: Input: _dummy_database@_dummy_table | ||
| POSTHOOK: Output: default@merge_skew_abort_b | ||
| POSTHOOK: Lineage: merge_skew_abort_b.key SCRIPT [] | ||
| POSTHOOK: Lineage: merge_skew_abort_b.value SCRIPT [] | ||
| PREHOOK: query: SELECT a.key, a.value, b.value | ||
| FROM merge_skew_abort_a a JOIN merge_skew_abort_b b ON a.key = b.key | ||
| PREHOOK: type: QUERY | ||
| PREHOOK: Input: default@merge_skew_abort_a | ||
| PREHOOK: Input: default@merge_skew_abort_b | ||
| #### A masked pattern was here #### | ||
| Status: Failed | ||
| Vertex failed, vertexName=Reducer 2, vertexId=vertex_#ID#, diagnostics=[Task failed, taskId=task_#ID#, diagnostics=[TaskAttempt 0 failed, info=[Error: Error while running task ( failure ) : attempt_#ID#:java.lang.RuntimeException: org.apache.hadoop.hive.ql.metadata.HiveException: Hive Runtime Error while processing row | ||
| #### A masked pattern was here #### | ||
| Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Hive Runtime Error while processing row | ||
| #### A masked pattern was here #### | ||
| Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Data skew detected in merge join, table alias 0 has accumulated 2 rows. | ||
| #### A masked pattern was here #### | ||
| ], TaskAttempt 1 failed, info=[Error: Error while running task ( failure ) : attempt_#ID#:java.lang.RuntimeException: org.apache.hadoop.hive.ql.metadata.HiveException: Hive Runtime Error while processing row | ||
| #### A masked pattern was here #### | ||
| Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Hive Runtime Error while processing row | ||
| #### A masked pattern was here #### | ||
| Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Data skew detected in merge join, table alias 0 has accumulated 2 rows. | ||
| #### A masked pattern was here #### | ||
| ]], Vertex did not succeed due to OWN_TASK_FAILURE, failedTasks:1 killedTasks:0, Vertex vertex_#ID# [Reducer 2] killed/failed due to:OWN_TASK_FAILURE] | ||
| DAG did not succeed due to VERTEX_FAILURE. failedVertices:1 killedVertices:0 | ||
| FAILED: Execution Error, return code 2 from org.apache.hadoop.hive.ql.exec.tez.TezTask. Vertex failed, vertexName=Reducer 2, vertexId=vertex_#ID#, diagnostics=[Task failed, taskId=task_#ID#, diagnostics=[TaskAttempt 0 failed, info=[Error: Error while running task ( failure ) : attempt_#ID#:java.lang.RuntimeException: org.apache.hadoop.hive.ql.metadata.HiveException: Hive Runtime Error while processing row | ||
| #### A masked pattern was here #### | ||
| Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Hive Runtime Error while processing row | ||
| #### A masked pattern was here #### | ||
| Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Data skew detected in merge join, table alias 0 has accumulated 2 rows. | ||
| #### A masked pattern was here #### | ||
| ], TaskAttempt 1 failed, info=[Error: Error while running task ( failure ) : attempt_#ID#:java.lang.RuntimeException: org.apache.hadoop.hive.ql.metadata.HiveException: Hive Runtime Error while processing row | ||
| #### A masked pattern was here #### | ||
| Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Hive Runtime Error while processing row | ||
| #### A masked pattern was here #### | ||
| Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Data skew detected in merge join, table alias 0 has accumulated 2 rows. | ||
| #### A masked pattern was here #### | ||
| ]], Vertex did not succeed due to OWN_TASK_FAILURE, failedTasks:1 killedTasks:0, Vertex vertex_#ID# [Reducer 2] killed/failed due to:OWN_TASK_FAILURE]DAG did not succeed due to VERTEX_FAILURE. failedVertices:1 killedVertices:0 |
Oops, something went wrong.
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
we can remove "Tez"
even "Tez" is the only execution engine we're currently supporting, this feature is theoretically orthogonal to that, so this is rather "Maximum number of rows allowed per join key in a single sort-merge reducer join task before..."