Does additional Solr search handler has any impact on performance?

Question

I am having three custom defined search handlers for Solr 4. It works fine, however I want to know whether it has any impact on RAM & CPU utilization and overall performance when considering an index size of 10 gb with replication setup.

I do not find any documentation on this. Any idea would be great.

Or do you recommend to stick to default handlers or use single handlers? Why?

Answer 1

Just by defining more request handler, no you should not have a performance impact. As quoted from the Reference Docs

A request handler is a Solr plug-in that defines the logic to be used when Solr processes a request.

So a request handler is the blueprint of processing logic to perform, when a request comes in. Just by defining more ways how this can be handled does not bear a performance impact. Of course this could be a matter of numbers. If you define hundreds or thousands of handlers that could have an impact. I just never saw such a configuration.

The operations that consume CPU and RAM are operations that interact with the index, like searching and indexing. When your clients start using the new request handlers, you will see a grown consumption in resources. But this is due to the usage by the client, not the mere definition of the way how to consume.