Query consistency policy

Learn how to use the query consistency policy to control the consistency mode of queries.

A workload group’s query consistency policy allows specifying options that control the consistency mode of queries.

The policy object

Each option consists of:

  • A typed Value - the value of the limit.
  • IsRelaxable - a boolean value that defines if the option can be relaxed by the caller, as part of the request’s request properties. Default is true.

The following limits are configurable:

NameTypeDescriptionSupported valuesDefault valueMatching client request property
QueryConsistencyQueryConsistencyThe consistency mode to use.Strong, Weak, or WeakAffinitizedByQuery, WeakAffinitizedByDatabaseStrongqueryconsistency
CachedResultsMaxAgetimespanThe maximum age of cached query results that can be returned.A non-negative timespannullquery_results_cache_max_age

Example

"QueryConsistencyPolicy": {
  "QueryConsistency": {
    "IsRelaxable": true,
    "Value": "Weak"
  },
  "CachedResultsMaxAge": {
    "IsRelaxable": true,
    "Value": "05:00:00"
  }
}

Monitoring

You can monitor the latency of the metadata snapshot age on nodes serving as weak consistency service heads by using the Weak consistency latency metric. For more information, see Query metrics.

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