Frequently asked questions about the Solr Performance Service 

FAQs include object enablement and performance impact.

Question: Is it a good idea to leave the Solr performance objects enabled 24/7?

Answer: It depends on your use cases. If you’re attempting to collect data pertaining to a problem that occurs sporadically, and you’ve chosen configuration values that don’t introduce a painful amount of performance overhead, there’s no reason you can’t keep the objects enabled on an ongoing basis.

Question: What kind of performance impact will enabling the Solr performance objects have?

Answer: Performance overhead, in terms of CPU and memory usage, should be negligible when using the DataStax Enterprise's default configuration values. However, the overhead introduced by enabling the objects varies as the configuration is modified (described in the following sections). For instance, setting longer TTLs and shorter refresh intervals leads to higher memory and disk consumption.

Question: Should I enable the Solr performance objects on every node in my cluster?

Answer: The Solr performance objects should only be enabled on search nodes, that is, nodes where indexes reside that can observe search operations. While it is perfectly acceptable to enable the objects across an entire cluster, enabling them on a single node for observation first is a good way to mitigate risk.

Question: Can I use existing Cassandra CF with secondary indexes on some columns, and create Solr indexes on other columns in the same CF?

Answer: Do not mix Solr indexes with Cassandra secondary indexes. Attempting to use both indexes on the same table is not supported.