I need to perform an online search in Solr i.e user need to find list of user which are online with particular criteria.
How I am handling this: we store the ids of user in a table and I send all online user id in Solr request like
&fq=-id:(id1 id2 id3 ............id5000)
The problem with this approach is that when ids become large, Solr is taking too much time to resolved and we need to transfer large request over the network.
One solution can be use of join in Solr but online data change regularly and I can't index data every time (say 5-10 min, it should be at-least an hour).
Other solution I think of firing this query internally from Solr based on certain parameter in URL. I don't have much idea about Solr internals so don't know how to proceed.
With Solr4's soft commits, committing has become cheap enough that it might be feasible to actually store the "online" flag directly in the user record, and just have &fq=online:true on your query. That reduces the overhead involved in sending 5000 id's over the wire and parsing them, and lets Solr optimize the query a bit. Whenever someone logs in or out, set their status and set the commitWithin on the update. It's worth a shot, anyway.