From 520ec0ff9db75267f627dc4615b2316a1a3d44d7 Mon Sep 17 00:00:00 2001 From: Josh Rosen Date: Thu, 30 Jul 2015 10:45:32 -0700 Subject: [SPARK-8850] [SQL] Enable Unsafe mode by default This pull request enables Unsafe mode by default in Spark SQL. In order to do this, we had to fix a number of small issues: **List of fixed blockers**: - [x] Make some default buffer sizes configurable so that HiveCompatibilitySuite can run properly (#7741). - [x] Memory leak on grouped aggregation of empty input (fixed by #7560 to fix this) - [x] Update planner to also check whether codegen is enabled before planning unsafe operators. - [x] Investigate failing HiveThriftBinaryServerSuite test. This turns out to be caused by a ClassCastException that occurs when Exchange tries to apply an interpreted RowOrdering to an UnsafeRow when range partitioning an RDD. This could be fixed by #7408, but a shorter-term fix is to just skip the Unsafe exchange path when RangePartitioner is used. - [x] Memory leak exceptions masking exceptions that actually caused tasks to fail (will be fixed by #7603). - [x] ~~https://issues.apache.org/jira/browse/SPARK-9162, to implement code generation for ScalaUDF. This is necessary for `UDFSuite` to pass. For now, I've just ignored this test in order to try to find other problems while we wait for a fix.~~ This is no longer necessary as of #7682. - [x] Memory leaks from Limit after UnsafeExternalSort cause the memory leak detector to fail tests. This is a huge problem in the HiveCompatibilitySuite (fixed by f4ac642a4e5b2a7931c5e04e086bb10e263b1db6). - [x] Tests in `AggregationQuerySuite` are failing due to NaN-handling issues in UnsafeRow, which were fixed in #7736. - [x] `org.apache.spark.sql.ColumnExpressionSuite.rand` needs to be updated so that the planner check also matches `TungstenProject`. - [x] After having lowered the buffer sizes to 4MB so that most of HiveCompatibilitySuite runs: - [x] Wrong answer in `join_1to1` (fixed by #7680) - [x] Wrong answer in `join_nulls` (fixed by #7680) - [x] Managed memory OOM / leak in `lateral_view` - [x] Seems to hang indefinitely in `partcols1`. This might be a deadlock in script transformation or a bug in error-handling code? The hang was fixed by #7710. - [x] Error while freeing memory in `partcols1`: will be fixed by #7734. - [x] After fixing the `partcols1` hang, it appears that a number of later tests have issues as well. - [x] Fix thread-safety bug in codegen fallback expression evaluation (#7759). Author: Josh Rosen Closes #7564 from JoshRosen/unsafe-by-default and squashes the following commits: 83c0c56 [Josh Rosen] Merge remote-tracking branch 'origin/master' into unsafe-by-default f4cc859 [Josh Rosen] Merge remote-tracking branch 'origin/master' into unsafe-by-default 963f567 [Josh Rosen] Reduce buffer size for R tests d6986de [Josh Rosen] Lower page size in PySpark tests 013b9da [Josh Rosen] Also match TungstenProject in checkNumProjects 5d0b2d3 [Josh Rosen] Add task completion callback to avoid leak in limit after sort ea250da [Josh Rosen] Disable unsafe Exchange path when RangePartitioning is used 715517b [Josh Rosen] Enable Unsafe by default --- .../util/collection/unsafe/sort/UnsafeExternalSorter.java | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'core') diff --git a/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeExternalSorter.java b/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeExternalSorter.java index c21990f4e4..866e0b4151 100644 --- a/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeExternalSorter.java +++ b/core/src/main/java/org/apache/spark/util/collection/unsafe/sort/UnsafeExternalSorter.java @@ -20,6 +20,9 @@ package org.apache.spark.util.collection.unsafe.sort; import java.io.IOException; import java.util.LinkedList; +import scala.runtime.AbstractFunction0; +import scala.runtime.BoxedUnit; + import com.google.common.annotations.VisibleForTesting; import org.slf4j.Logger; import org.slf4j.LoggerFactory; @@ -90,6 +93,17 @@ public final class UnsafeExternalSorter { this.fileBufferSizeBytes = (int) conf.getSizeAsKb("spark.shuffle.file.buffer", "32k") * 1024; this.pageSizeBytes = conf.getSizeAsBytes("spark.buffer.pageSize", "64m"); initializeForWriting(); + + // Register a cleanup task with TaskContext to ensure that memory is guaranteed to be freed at + // the end of the task. This is necessary to avoid memory leaks in when the downstream operator + // does not fully consume the sorter's output (e.g. sort followed by limit). + taskContext.addOnCompleteCallback(new AbstractFunction0() { + @Override + public BoxedUnit apply() { + freeMemory(); + return null; + } + }); } // TODO: metrics tracking + integration with shuffle write metrics -- cgit v1.2.3