[
https://issues.apache.org/jira/browse/CASSANDRA-14554?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16711307#comment-16711307
]
Benedict commented on CASSANDRA-14554:
--------------------------------------
Thanks. I was just a little confused as to why it was in {{abort}} - in
{{SSTableRewriter}} we do this on commit / switchWriter. I can see now that
there's an invocation of {{SSTableMultiWriter.abortOrDie}} (which invokes
{{abort}}) in {{RangeAwareSSTableWriter}} on commit).
Probably this should all be rejigged slightly as you say, moving both of these
to {{SSTableWriter}}, perhaps with a parameter to {{abort}} to indicate you
want to do this (because in the case of a full abort it's preferable to leave
cleanup to the {{LogFile}}'s abort).
> LifecycleTransaction encounters ConcurrentModificationException when used in
> multi-threaded context
> ---------------------------------------------------------------------------------------------------
>
> Key: CASSANDRA-14554
> URL: https://issues.apache.org/jira/browse/CASSANDRA-14554
> Project: Cassandra
> Issue Type: Bug
> Components: Streaming and Messaging
> Reporter: Dinesh Joshi
> Assignee: Dinesh Joshi
> Priority: Major
> Fix For: 4.0, 3.0.x, 3.11.x
>
>
> When LifecycleTransaction is used in a multi-threaded context, we encounter
> this exception -
> {quote}java.util.ConcurrentModificationException: null
> at
> java.util.LinkedHashMap$LinkedHashIterator.nextNode(LinkedHashMap.java:719)
> at java.util.LinkedHashMap$LinkedKeyIterator.next(LinkedHashMap.java:742)
> at java.lang.Iterable.forEach(Iterable.java:74)
> at
> org.apache.cassandra.db.lifecycle.LogReplicaSet.maybeCreateReplica(LogReplicaSet.java:78)
> at org.apache.cassandra.db.lifecycle.LogFile.makeRecord(LogFile.java:320)
> at org.apache.cassandra.db.lifecycle.LogFile.add(LogFile.java:285)
> at
> org.apache.cassandra.db.lifecycle.LogTransaction.trackNew(LogTransaction.java:136)
> at
> org.apache.cassandra.db.lifecycle.LifecycleTransaction.trackNew(LifecycleTransaction.java:529)
> {quote}
> During streaming we create a reference to a {{LifeCycleTransaction}} and
> share it between threads -
> [https://github.com/apache/cassandra/blob/5cc68a87359dd02412bdb70a52dfcd718d44a5ba/src/java/org/apache/cassandra/db/streaming/CassandraStreamReader.java#L156]
> This is used in a multi-threaded context inside {{CassandraIncomingFile}}
> which is an {{IncomingStreamMessage}}. This is being deserialized in parallel.
> {{LifecycleTransaction}} is not meant to be used in a multi-threaded context
> and this leads to streaming failures due to object sharing. On trunk, this
> object is shared across all threads that transfer sstables in parallel for
> the given {{TableId}} in a {{StreamSession}}. There are two options to solve
> this - make {{LifecycleTransaction}} and the associated objects thread safe,
> scope the transaction to a single {{CassandraIncomingFile}}. The consequences
> of the latter option is that if we experience streaming failure we may have
> redundant SSTables on disk. This is ok as compaction should clean this up. A
> third option is we synchronize access in the streaming infrastructure.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org
For additional commands, e-mail: commits-h...@cassandra.apache.org
