Hi,
we are using Apache Solr Cloud within a production environment. If the
maximum heap-space is reached the Solr access time slows down, because
of the working garbage collector for a small amount of time.
We use the following configuration:
- Apache Tomcat as webserver to run the Solr web application
- 13 indices with about 1500000 entries (300 MB)
- 5 server with one replication per index (5 GB max heap-space)
- All indices have the following caches
- maximum document-cache-size is 4096 entries, all other indices
have between 64 and 1536 entries
- maximum query-cache-size is 1024 entries, all other indices have
between 64 and 768
- maximum filter-cache-size is 1536 entries, all other i ndices have
between 64 and 1024
- the directory-factory-implementation is NRTCachingDirectoryFactory
- the index is updated once per hour (no auto commit)
- ca. 5000 requests per hour per server
- large filter-queries (up to 15000 bytes and 1500 boolean operations)
- many facet-queries (30%)
Behaviour:
Started with 512 MB heap space. Over several days the heap-space grow
up, until the 5 GB was reached. At this moment the described problem
occurs. From this time on the heap-space-useage is between 50 and 90
percent. No OutOfMemoryException occurs.
Questions:
1. Why does Solr use 5 GB ram, with this small amount of data?
2. Which impact does the large filter-queries have in relation to ram usage?
Thanks!
Johannes Siegert
