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author | zsxwing <zsxwing@gmail.com> | 2014-05-26 23:17:39 -0700 |
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committer | Aaron Davidson <aaron@databricks.com> | 2014-05-26 23:17:39 -0700 |
commit | 549830b0db2c8b069391224f3a73bb0d7f397f71 (patch) | |
tree | dba55b1fb8bc76ddf16d2093805ab27b34775992 | |
parent | 90e281b55aecbfbe4431ac582311d5790fe7aad3 (diff) | |
download | spark-549830b0db2c8b069391224f3a73bb0d7f397f71.tar.gz spark-549830b0db2c8b069391224f3a73bb0d7f397f71.tar.bz2 spark-549830b0db2c8b069391224f3a73bb0d7f397f71.zip |
SPARK-1932: Fix race conditions in onReceiveCallback and cachedPeers
`var cachedPeers: Seq[BlockManagerId] = null` is used in `def replicate(blockId: BlockId, data: ByteBuffer, level: StorageLevel)` without proper protection.
There are two place will call `replicate(blockId, bytesAfterPut, level)`
* https://github.com/apache/spark/blob/17f3075bc4aa8cbed165f7b367f70e84b1bc8db9/core/src/main/scala/org/apache/spark/storage/BlockManager.scala#L644 runs in `connectionManager.futureExecContext`
* https://github.com/apache/spark/blob/17f3075bc4aa8cbed165f7b367f70e84b1bc8db9/core/src/main/scala/org/apache/spark/storage/BlockManager.scala#L752 `doPut` runs in `connectionManager.handleMessageExecutor`. `org.apache.spark.storage.BlockManagerWorker` calls `blockManager.putBytes` in `connectionManager.handleMessageExecutor`.
As they run in different `Executor`s, this is a race condition which may cause the memory pointed by `cachedPeers` is not correct even if `cachedPeers != null`.
The race condition of `onReceiveCallback` is that it's set in `BlockManagerWorker` but read in a different thread in `ConnectionManager.handleMessageExecutor`.
Author: zsxwing <zsxwing@gmail.com>
Closes #887 from zsxwing/SPARK-1932 and squashes the following commits:
524f69c [zsxwing] SPARK-1932: Fix race conditions in onReceiveCallback and cachedPeers
-rw-r--r-- | core/src/main/scala/org/apache/spark/network/ConnectionManager.scala | 3 | ||||
-rw-r--r-- | core/src/main/scala/org/apache/spark/storage/BlockManager.scala | 2 |
2 files changed, 3 insertions, 2 deletions
diff --git a/core/src/main/scala/org/apache/spark/network/ConnectionManager.scala b/core/src/main/scala/org/apache/spark/network/ConnectionManager.scala index dcbbc18531..5dd5fd0047 100644 --- a/core/src/main/scala/org/apache/spark/network/ConnectionManager.scala +++ b/core/src/main/scala/org/apache/spark/network/ConnectionManager.scala @@ -93,7 +93,8 @@ private[spark] class ConnectionManager(port: Int, conf: SparkConf, implicit val futureExecContext = ExecutionContext.fromExecutor( Utils.newDaemonCachedThreadPool("Connection manager future execution context")) - private var onReceiveCallback: (BufferMessage, ConnectionManagerId) => Option[Message]= null + @volatile + private var onReceiveCallback: (BufferMessage, ConnectionManagerId) => Option[Message] = null private val authEnabled = securityManager.isAuthenticationEnabled() diff --git a/core/src/main/scala/org/apache/spark/storage/BlockManager.scala b/core/src/main/scala/org/apache/spark/storage/BlockManager.scala index 6534095811..6e450081dc 100644 --- a/core/src/main/scala/org/apache/spark/storage/BlockManager.scala +++ b/core/src/main/scala/org/apache/spark/storage/BlockManager.scala @@ -772,7 +772,7 @@ private[spark] class BlockManager( /** * Replicate block to another node. */ - var cachedPeers: Seq[BlockManagerId] = null + @volatile var cachedPeers: Seq[BlockManagerId] = null private def replicate(blockId: BlockId, data: ByteBuffer, level: StorageLevel) { val tLevel = StorageLevel( level.useDisk, level.useMemory, level.useOffHeap, level.deserialized, 1) |