Thu, 22 Sep 2016

Checking Solr index with nagios: obsolete versions

— SjG @ 12:33 pm

I needed to check that the index process that populates the Solr index succeeded and didn’t die during the night, leaving an empty index.

To make things more complicated, the versions of Solr and nagios in use are probably not the latest.

The check_solr -o numdocs command doesn’t work with our Solr configuration. But the internet tells me that the Solr query http://localhost:8983/solr/select/?debug=q‌uery&q=*:* includes the size of the result set. Testing it, I found this to be true:

   <lst name="responseHeader">
      <int name="status">0</int>
      <int name="QTime">0
      <lst name="params">
         <str name="q">*:*</str>
         <str name="debug">q‌uery</str>
   <result name="response" numFound="9832" start="0">

I want to use nagios to check that that numFound is never zero (or too small). I thought I’d just be able to use a nagios regex:

check_http -H localhost -p 8983 -u "/solr/select/?debug=query&q=*:*" -lr 'numFound=\"\d{2+}"'

It didn’t work. To make a long story short, there’s regex and then there’s regex. The kind that works for nagios is:

check_http -H localhost -p 8983 -u "/solr/select/?debug=query&q=*:*" -lr 'numFound=\"[1-9][0-9][0-9]'

This guarantees at least a hundred docs are in the index.