Query metrics MBean 

The query metrics MBean is useful for troubleshooting query performance, tuning the Solr configuration, such as the schema and caches, and tuning server resources, such as the JVM heap.

The query metrics MBean is useful for troubleshooting query performance, tuning the Solr configuration, such as the schema and caches, and tuning server resources, such as the JVM heap. The query metrics MBean records the amount of time spent to execute several main phases of a distributed query on the index.

The query metrics MBean measures latency in microseconds. Metrics can be grouped by query, by providing an additional query.name parameter. For example, assuming you are using a Solr core named demo.solr and have indexed a field named type, this URL provides the additional query.name parameter:
http://localhost:8983/solr/demo.solr/select/?q=type:1&query.name=myquery
All metrics collected under a given query name are recorded and retrieved separately. If a query name is not provided, all metrics are recorded together.

Main operational phases 

The main phases of a distributed query operation are:
COORDINATE
Comprises the total amount of time spent by the coordinator node to distribute the query and gather/process results from shards. This value is computed only on query coordinator nodes.
EXECUTE
Comprises the time spent by a single shard to execute the actual index query. This value is computed on the local node executing the shard query.
RETRIEVE
Comprises the time spent by a node to retrieve a single row from Cassandra. This value will be computed on the local node hosting the requested data.

Query metrics MBean set operations 

Operations are:

  • setEnabled(boolean enabled)

    Enables/disables metrics recording. Enabled by default.

  • isEnabled()

    Checks if metrics recording is enabled.

  • getLatencyPercentile(String phase, String query, double percentile)

    Gets a query latency percentile by its query name, which is optional and can be null, and phase.

  • getRecordedLatencyCount(String phase, String query)

    Gets the total count of recorded latency metrics by its query name, which is optional and can be null, and phase.

  • getUnrecordedLatencyCount()

    Gets the total count of unrecorded latency values due to exceeding the maximum tracked latency, which is 10 minutes.

  • resetLatency(String query)

    Resets latency metrics for the given query name, which is optional and can be null.

  • resetLatencies()

    Resets all latency metrics.