[SOLR-4373] In multicore, lib directives in solrconfig.xml cause conflict and clobber directives from earlier cores

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.1, 4.2
• Fix Version/s: 4.2
• Component/s: multicore
• Labels: lib multicore
• Assignee: Chris M. Hostetter
• Reporter: Alexandre Rafalovitch
• Created: 29/Jan/13 01:07
• Updated: 10/May/13 10:34
• Resolved: 11/Mar/13 21:17

Description

Having lib directives in the solrconfig.xml files of multiple cores can cause problems when using multi-threaded core initialization – which is the default starting with Solr 4.1.

The problem manifests itself as init errors in the logs related to not being able to find classes located in plugin jars, even though earlier log messages indicated that those jars had been added to the classpath.

One work around is to set coreLoadThreads="1" in your solr.xml file – forcing single threaded core initialization. For example...

<?xml version="1.0" encoding="utf-8" ?>
<solr coreLoadThreads="1">
  <cores adminPath="/admin/cores">
    <core name="core1" instanceDir="core1" />
    <core name="core2" instanceDir="core2" />
  </cores>
</solr>

(Similar problems may occur if multiple cores are initialized concurrently using the /admin/cores handler)

Issue Links

• relates to: LUCENE-4796 NamedSPILoader.reload needs to be synchronized
• relates to: SOLR-4063 CoreContainer should be able to load multiple SolrCore's in parallel rather than just serially.