[STANBOL-763] ConcurrentModificationException in ManagedSolrServer when a Solr index archive becomes available

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: commons-0.11.0
• Component/s: Commons
• Assignee: Rupert Westenthaler
• Reporter: Rupert Westenthaler
• Created: 09/Oct/12 06:45
• Updated: 22/Jan/13 12:08
• Resolved: 09/Oct/12 11:08

Description

The stacktrace

08.10.2012 11:21:29.786 WARN [DataFileTrackingDaemon] org.apache.stanbol.commons.stanboltools.datafileprovider.impl.tracking.DataFileTrackerImpl Exception from Listener 'org.apache.stanbol.commons.solr.managed.impl.ManagedSolrServerImpl$IndexArchiveTracker@25bbd50b' while calling available for resource 'default.solrindex.zip'! java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextEntry(HashMap.java:793)
at java.util.HashMap$KeyIterator.next(HashMap.java:828)
at java.util.Collections$UnmodifiableCollection$1.next(Collections.java:1008)
at org.apache.stanbol.commons.solr.managed.impl.ManagedSolrServerImpl$IndexArchiveTracker.available(ManagedSolrServerImpl.java:1049)
at org.apache.stanbol.commons.stanboltools.datafileprovider.impl.tracking.DataFileTrackerImpl$TrackingDaemon.fire(DataFileTrackerImpl.java:416)
at org.apache.stanbol.commons.stanboltools.datafileprovider.impl.tracking.DataFileTrackerImpl$TrackingDaemon.run(DataFileTrackerImpl.java:358)
at java.lang.Thread.run(Thread.java:680)

If this happens the available Solr Archive ("

{name}.solrindex.zip") will not be initialised. Users will see the ReferencedSite {name}

but requests will result in Exceptions.

Users that experience this can try to

• Stop/Start the SolrYard that uses the SolrCore with the name {name}
  * Delete the "{name}

  .solrindex.zip"; wait for 5+sec; re-create "

  {name}

  .solrindex.zip" in the /datafiles directory

both actions will again trigger the initialization of the Solr Archive.