Saturday, August 24, 2013

Manually editing Solr's clusterstate.json on Zookeeper

There will probably come a time when you want to do something not readily covered in Solr's APIs.  Manually editing the clusterstate.json is easy to do but should be approached with caution.

I wanted to drop all shards from a single host from my Solr cluster (didn't care about losing the data) and do a little spring cleaning.  To open a command-line interface with ZK:

/path/to/zookeeper/bin/ -server

Then simply:

get /clusterstate.json

Place that content into a local file.  After backing up the original content, make your edits.  For instance, to drop the dead nodes, delete JSON elements with "down" states:

To upload your new clusterstate.json (no need to halt services):

/path/to/zookeeper/bin/ -server set /clusterstate.json "`cat /local/path/to/clusterstate.json`"