[SOLR-1757] DIH multithreading sometimes throws NPE

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.4
• Fix Version/s: 1.5
• Component/s: contrib - DataImportHandler
• Labels: dih multithread

Environment

tomcat 6.0.x, jdk 1.6.x on windows xp 32bit

• Assignee: Noble Paul
• Reporter: Michael Henson
• Created: 05/Feb/10 02:12
• Updated: 09/Feb/10 05:26
• Resolved: 09/Feb/10 05:26

Description

When the "threads" attribute is set on a root entity in the DIH's data-config.xml, the multithreading code sometimes throws a NullPointerException after the full-index command is given.

I haven't yet been able to figure out exactly which reference holds the null or why, but it does happen consistently with the same backtrace.

My configuration is:

1. Multi-core Solr under tomcat
2. Using JdbcDataSource and the default SqlEntityProcessor

To reproduce:

1. Add the attribute threads="2" to the root entity declaration in data-config.xml
2. Send the full-import command either directly to .../core/dataimport?command=full-import or through the /admin/dataimport.jsp control panel.
3. Wait for the NPE to show up in the logs/console