[
https://issues.apache.org/jira/browse/CASSANDRA-8399?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Joshua McKenzie updated CASSANDRA-8399:
---------------------------------------
Attachment: 8399_fix_empty_results.txt
Good catch; the role of the readOrdering in CFS w/regards to deletion of
sstables wasn't clear to me prior and the possibility of a race between OpOrder
start and sstable ref count decrement was subtle enough that I missed it.
Attached a patch that replicates CASSANDRA-8513 for current 2.1.
Ultimately, it feels like the right solution is to untangle the various
getScanner calls in SSTR and have a separate getReadScanner and
getCompactionScanner path, one without reference counting and one with. This
current workaround loses the return of an empty SSTableScanner on the
compaction path and also enforces ref counting on range queries which is not
ideal. I'll create another ticket for these changes.
I don't like us having two separate paradigms for resource tracking /
protection on SSTableReaders (OpOrder and ref counting) as mentally modelling
state and potential races becomes considerably more difficult with different
primitives used on different paths.
> Reference Counter exception when dropping user type
> ---------------------------------------------------
>
> Key: CASSANDRA-8399
> URL: https://issues.apache.org/jira/browse/CASSANDRA-8399
> Project: Cassandra
> Issue Type: Bug
> Reporter: Philip Thompson
> Assignee: Joshua McKenzie
> Fix For: 2.1.3
>
> Attachments: 8399_fix_empty_results.txt, node2.log, ubuntu-8399.log
>
>
> When running the dtest
> {{user_types_test.py:TestUserTypes.test_type_keyspace_permission_isolation}}
> with the current 2.1-HEAD code, very frequently, but not always, when
> dropping a type, the following exception is seen:{code}
> ERROR [MigrationStage:1] 2014-12-01 13:54:54,824 CassandraDaemon.java:170 -
> Exception in thread Thread[MigrationStage:1,5,main]
> java.lang.AssertionError: Reference counter -1 for
> /var/folders/v3/z4wf_34n1q506_xjdy49gb780000gn/T/dtest-eW2RXj/test/node2/data/system/schema_keyspaces-b0f2235744583cdb9631c43e59ce3676/system-sche
> ma_keyspaces-ka-14-Data.db
> at
> org.apache.cassandra.io.sstable.SSTableReader.releaseReference(SSTableReader.java:1662)
> ~[main/:na]
> at
> org.apache.cassandra.io.sstable.SSTableScanner.close(SSTableScanner.java:164)
> ~[main/:na]
> at
> org.apache.cassandra.utils.MergeIterator.close(MergeIterator.java:62)
> ~[main/:na]
> at
> org.apache.cassandra.db.ColumnFamilyStore$8.close(ColumnFamilyStore.java:1943)
> ~[main/:na]
> at
> org.apache.cassandra.db.ColumnFamilyStore.filter(ColumnFamilyStore.java:2116)
> ~[main/:na]
> at
> org.apache.cassandra.db.ColumnFamilyStore.getRangeSlice(ColumnFamilyStore.java:2029)
> ~[main/:na]
> at
> org.apache.cassandra.db.ColumnFamilyStore.getRangeSlice(ColumnFamilyStore.java:1963)
> ~[main/:na]
> at
> org.apache.cassandra.db.SystemKeyspace.serializedSchema(SystemKeyspace.java:744)
> ~[main/:na]
> at
> org.apache.cassandra.db.SystemKeyspace.serializedSchema(SystemKeyspace.java:731)
> ~[main/:na]
> at org.apache.cassandra.config.Schema.updateVersion(Schema.java:374)
> ~[main/:na]
> at
> org.apache.cassandra.config.Schema.updateVersionAndAnnounce(Schema.java:399)
> ~[main/:na]
> at
> org.apache.cassandra.db.DefsTables.mergeSchema(DefsTables.java:167)
> ~[main/:na]
> at
> org.apache.cassandra.db.DefinitionsUpdateVerbHandler$1.runMayThrow(DefinitionsUpdateVerbHandler.java:49)
> ~[main/:na]
> at
> org.apache.cassandra.utils.WrappedRunnable.run(WrappedRunnable.java:28)
> ~[main/:na]
> at
> java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
> ~[na:1.7.0_67]
> at java.util.concurrent.FutureTask.run(FutureTask.java:262)
> ~[na:1.7.0_67]
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
> ~[na:1.7.0_67]
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
> [na:1.7.0_67]
> at java.lang.Thread.run(Thread.java:745) [na:1.7.0_67]{code}
> Log of the node with the error is attached.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
