Solr excessive logging and autowarming - is it normal? - solr

Question

I am pretty new to Solr, so I apologize if this is a stupid question :)
I have a Solr process running and logging stuff to file. Log level set to INFO I believe. Regardless of this, it still logs like crazy even though nothing being searched really. Logs contain records like these mostly:
INFO: autowarming result for Searcher#7c35a3be main
queryResultCache{lookups=0,hits=0,hitratio=0.00,inserts=0,evictions=0,size=0,warmupTime=0,cumulative_lookups=0,cumulative_hits=0,cumulative_hitratio=0.00,cumulative_inserts=0,cumulative_evictions=0}
May 31, 2012 6:53:45 PM org.apache.solr.search.SolrIndexSearcher warm
INFO: autowarming Searcher#7c35a3be main from Searcher#7dde0950 main
documentCache{lookups=0,hits=0,hitratio=0.00,inserts=0,evictions=0,size=0,warmupTime=0,cumulative_lookups=6188938,cumulative_hits=2441,cumulative_hitratio=0.00,cumulative_inserts=6186497,cumulative_evictions=4581707}
May 31, 2012 6:53:45 PM org.apache.solr.search.SolrIndexSearcher warm
INFO: autowarming result for Searcher#7c35a3be main
documentCache{lookups=0,hits=0,hitratio=0.00,inserts=0,evictions=0,size=0,warmupTime=0,cumulative_lookups=6188938,cumulative_hits=2441,cumulative_hitratio=0.00,cumulative_inserts=6186497,cumulative_evictions=4581707}
May 31, 2012 6:53:45 PM org.apache.solr.core.QuerySenderListener newSearcher
INFO: QuerySenderListener sending requests to Searcher#7c35a3be main
May 31, 2012 6:53:45 PM org.apache.solr.core.QuerySenderListener newSearcher
INFO: QuerySenderListener done.
May 31, 2012 6:53:45 PM org.apache.solr.core.SolrCore registerSearcher
INFO: [] Registered new searcher Searcher#7c35a3be main
May 31, 2012 6:53:45 PM org.apache.solr.search.SolrIndexSearcher close
INFO: Closing Searcher#7dde0950 main
fieldValueCache{lookups=0,hits=0,hitratio=0.00,inserts=0,evictions=0,size=0,warmupTime=0,cumulative_lookups=0,cumulative_hits=0,cumulative_hitratio=0.00,cumulative_inserts=0,cumulative_evictions=0}
filterCache{lookups=0,hits=0,hitratio=0.00,inserts=0,evictions=0,size=0,warmupTime=0,cumulative_lookups=0,cumulative_hits=0,cumulative_hitratio=0.00,cumulative_inserts=0,cumulative_evictions=0}
queryResultCache{lookups=0,hits=0,hitratio=0.00,inserts=0,evictions=0,size=0,warmupTime=0,cumulative_lookups=0,cumulative_hits=0,cumulative_hitratio=0.00,cumulative_inserts=0,cumulative_evictions=0}
documentCache{lookups=0,hits=0,hitratio=0.00,inserts=0,evictions=0,size=0,warmupTime=0,cumulative_lookups=6188938,cumulative_hits=2441,cumulative_hitratio=0.00,cumulative_inserts=6186497,cumulative_evictions=4581707}
May 31, 2012 6:53:45 PM org.apache.solr.update.processor.LogUpdateProcessor finish
Is this normal? This seems to put a pretty hefty load on the system(nothing to dramatic, but still).
I am just trying to understand what exactly it is doing and why.

Answer 1

IMHO in production environment, until you have a problem, you should use WARNING level (as application servers do).
You can configure logging through Solr admin console (for local Jetty URL would be: http://localhost:8983/solr/admin/logging) and it can be done for every package/class separately.
Logging levels are:
FINEST
FINE
CONFIG
INFO
WARNING
SEVERE
OFF
If you leave it unset, INFO is used.

Answer 2

By default the logging level is info.
When solr loads the core, it will load all the configuration files for the cores and auto warm the caches and all this would be logged out in the log files.
Configuring logging can help you configure your logging to the level you need.
You can configure the autowarming for Solr in the solrconfig.xml configuration file.