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https://issues.apache.org/jira/browse/OAK-2294?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14226472#comment-14226472
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Michael Dürig commented on OAK-2294:
------------------------------------
The root cause for this issue is a limitation of the SegmentMK that we are
hitting here. Apparently the SegmentMK can't handle more than 255 property
names in a template when those are spread over separate segments. So this isn't
a concurrency issue after all. I was able to reproduce this within a single
thread by just adding *many* properties to the same node. The reason this is
more expressed in a concurrent setting is that there the chances are higher
that the property names get spread across various segments.
The reason we are seeing this issue with the versioning code (while adding
labels) is that labels are maintained as reference properties on the version
history node.
[~tmueller] your [comment |
https://github.com/apache/jackrabbit-oak/blob/trunk/oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/segment/SegmentWriter.java#L955]
in the {{SegmentWriter}} class was a great help in finding this. Could you
summarise here why spreading property names across more than 255 segments
doesn't work as you are stating in that comment?
> Corrupt repository after concurrent version operations
> ------------------------------------------------------
>
> Key: OAK-2294
> URL: https://issues.apache.org/jira/browse/OAK-2294
> Project: Jackrabbit Oak
> Issue Type: Bug
> Components: segmentmk
> Reporter: Michael Dürig
> Priority: Blocker
> Attachments: OAK-2294-2.patch, OAK-2294.patch
>
>
> Performing version operations (checkin / checkout / addVersionLabel)
> concurrently can corrupt the repository.
> Executing the following code in parallel from multiple threads demonstrates
> this:
> {code}
> Version version = versionManager.checkin(vPath);
> versionManager.checkout(vPath);
> String label = version.getName() + " " + Thread.currentThread().getName();
> version.getContainingHistory()
> .addVersionLabel(version.getName(), label, true);
> {code}
> In my tests this eventually lead to all sorts of exceptions:
> {noformat}
> java.lang.IllegalStateException: RefId '85' doesn't exist in data segment
> 0c5c0814-902c-429c-ad41-cd82aea276a2
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.getRefId(Segment.java:196)
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.internalReadRecordId(Segment.java:307)
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.readRecordId(Segment.java:303)
> at
> org.apache.jackrabbit.oak.plugins.segment.MapRecord.getBucketList(MapRecord.java:134)
> at
> org.apache.jackrabbit.oak.plugins.segment.MapRecord.getEntries(MapRecord.java:347)
> at
> org.apache.jackrabbit.oak.plugins.segment.MapRecord.getEntries(MapRecord.java:325)
> at
> org.apache.jackrabbit.oak.plugins.segment.MapRecord.compare(MapRecord.java:474)
> at
> org.apache.jackrabbit.oak.plugins.segment.MapRecord.compare(MapRecord.java:394)
> at
> org.apache.jackrabbit.oak.plugins.segment.SegmentNodeState.compareAgainstBaseState(SegmentNodeState.java:544)
> ...
> {noformat}
> {noformat}
> java.lang.IllegalStateException: String is too long: 2159501163930351661
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.loadString(Segment.java:352)
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.readString(Segment.java:319)
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.readString(Segment.java:313)
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.loadTemplate(Segment.java:418)
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.readTemplate(Segment.java:367)
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.readTemplate(Segment.java:361)
> at
> org.apache.jackrabbit.oak.plugins.segment.SegmentNodeState.getTemplate(SegmentNodeState.java:78)
> at
> org.apache.jackrabbit.oak.plugins.segment.SegmentNodeState.compareAgainstBaseState(SegmentNodeState.java:408)
> ...
> {noformat}
> {noformat}
> java.lang.IllegalStateException
> at
> com.google.common.base.Preconditions.checkState(Preconditions.java:134)
> at
> org.apache.jackrabbit.oak.plugins.segment.file.TarWriter.writeEntry(TarWriter.java:206)
> at
> org.apache.jackrabbit.oak.plugins.segment.file.TarWriter.writeEntry(TarWriter.java:200)
> at
> org.apache.jackrabbit.oak.plugins.segment.file.FileStore.writeSegment(FileStore.java:682)
> at
> org.apache.jackrabbit.oak.plugins.segment.SegmentWriter.flush(SegmentWriter.java:228)
> at
> org.apache.jackrabbit.oak.plugins.segment.SegmentWriter.prepare(SegmentWriter.java:329)
> at
> org.apache.jackrabbit.oak.plugins.segment.SegmentWriter.writeTemplate(SegmentWriter.java:969)
> at
> org.apache.jackrabbit.oak.plugins.segment.SegmentWriter.writeNode(SegmentWriter.java:1039)
> at
> org.apache.jackrabbit.oak.plugins.segment.SegmentWriter$2.childNodeChanged(SegmentWriter.java:1062)
> at
> org.apache.jackrabbit.oak.plugins.memory.ModifiedNodeState.compareAgainstBaseState(ModifiedNodeState.java:395)
> ...
> {noformat}
> {noformat}
> Caused by: java.lang.IllegalArgumentException: Invalid type tag: 81
> at org.apache.jackrabbit.oak.api.Type.fromTag(Type.java:202)
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.loadTemplate(Segment.java:418)
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.readTemplate(Segment.java:367)
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.readTemplate(Segment.java:361)
> at
> org.apache.jackrabbit.oak.plugins.segment.SegmentNodeState.getTemplate(SegmentNodeState.java:78)
> at
> org.apache.jackrabbit.oak.plugins.segment.SegmentNodeState.getProperty(SegmentNodeState.java:122)
> ...
> {noformat}
> {noformat}
> Caused by: java.lang.IllegalStateException
> at
> com.google.common.base.Preconditions.checkState(Preconditions.java:134)
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.pos(Segment.java:178)
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.loadString(Segment.java:326)
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.readString(Segment.java:319)
> at
> org.apache.jackrabbit.oak.plugins.segment.Segment.readString(Segment.java:313)
> at
> org.apache.jackrabbit.oak.plugins.segment.SegmentPropertyState.getValue(SegmentPropertyState.java:174)
> at
> org.apache.jackrabbit.oak.plugins.segment.SegmentPropertyState.getValue(SegmentPropertyState.java:147)
> at
> org.apache.jackrabbit.oak.plugins.memory.AbstractPropertyState.equal(AbstractPropertyState.java:53)
> ...
> {noformat}
> Will attach a patch with a test case shortly.
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