[SOLR-2623] Solr JMX MBeans do not survive core reloads

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.4, 1.4.1, 3.1, 3.2
• Fix Version/s: 3.4, 4.0-ALPHA
• Component/s: multicore
• Assignee: Shalin Shekhar Mangar
• Reporter: Alexey Serba
• Created: 28/Jun/11 03:58
• Updated: 30/Jul/13 22:19
• Resolved: 20/Jul/11 10:20

Description

Solr JMX MBeans do not survive core reloads

"Steps to reproduce"

sh> cd example
sh> vi multicore/core0/conf/solrconfig.xml # enable jmx
sh> java -Dcom.sun.management.jmxremote -Dsolr.solr.home=multicore -jar start.jar
sh> echo 'open 8842 # 8842 is java pid
> domain solr/core0
> beans
> ' | java -jar jmxterm-1.0-alpha-4-uber.jar
....
solr/core0:id=core0,type=core
solr/core0:id=org.apache.solr.handler.StandardRequestHandler,type=org.apache.solr.handler.StandardRequestHandler
solr/core0:id=org.apache.solr.handler.StandardRequestHandler,type=standard
solr/core0:id=org.apache.solr.handler.XmlUpdateRequestHandler,type=/update
solr/core0:id=org.apache.solr.handler.XmlUpdateRequestHandler,type=org.apache.solr.handler.XmlUpdateRequestHandler
...
solr/core0:id=org.apache.solr.search.SolrIndexSearcher,type=searcher
solr/core0:id=org.apache.solr.update.DirectUpdateHandler2,type=updateHandler
sh> curl 'http://localhost:8983/solr/admin/cores?action=RELOAD&core=core0'
sh> echo 'open 8842 # 8842 is java pid
> domain solr/core0
> beans
> ' | java -jar jmxterm-1.0-alpha-4-uber.jar
# there's only one bean left after Solr core reload
solr/core0:id=org.apache.solr.search.SolrIndexSearcher,type=Searcher@2e831a91 main

The root cause of this is Solr core reload behavior:

1. create new core (which overwrites existing registered MBeans)
2. register new core and close old one (we remove/un-register MBeans on oldCore.close)

The correct sequence is:

1. unregister MBeans from old core
2. create and register new core
3. close old core without touching MBeans

Issue Links

• is duplicated by: SOLR-3615 JMX Mbeans disappear on core reload