On 11/21/2018 8:36 AM, Rajdeep Sahoo wrote:
The problem is that we are using master slave solr configuration and for
similar type of query sometime it is taking 512 ms and sometime it is 29
ms . we are observing this issue since the query modification. As part of
modification we have reduced a large no of facet.field param. In
solrconfig.xml file we have changed the cache size and reloaded the the
cores as part of this modification.
Reloading cores is not clearing the cache. Is there any reason why we
are getting this much of difference in response time for similar type of
queries.
What *SPECIFIC* evidence do you have that reloading the cores isn't
emptying caches? Have you gone into plugins/stats and checked to see
what the current cache sizes are?
Often when a query fully utilizes Solr's caches, it will return in one
or two milliseconds. A 29 millisecond query time probably means that
the result did NOT come from Solr's caches, unless the machine is
particularly slow.
The cache that is likely affecting query performance in your case is not
part of Solr at all -- it's the operating system. All modern operating
systems use unallocated memory to cache any data on disk that has been
read or written. Solr is highly reliant on this OS feature for good
performance -- if you do not have extra memory not allocated to
programs, Solr performance is probably going to be very bad.
https://wiki.apache.org/solr/SolrPerformanceProblems#RAM
Thanks,
Shawn
