Information about progress made in the execution of a StreamingQuery during a trigger. Each event relates to processing done for a single trigger of the streaming query. Events are emitted even when no new data is available to be processed.

param: id A unique query id that persists across restarts. See StreamingQuery.id(). param: runId A query id that is unique for every start/restart. See StreamingQuery.runId(). param: name User-specified name of the query, null if not specified. param: timestamp Beginning time of the trigger in ISO8601 format, i.e. UTC timestamps. param: batchId A unique id for the current batch of data being processed. Note that in the case of retries after a failure a given batchId my be executed more than once. Similarly, when there is no data to be processed, the batchId will not be incremented. param: batchDuration The process duration of each batch. param: durationMs The amount of time taken to perform various operations in milliseconds. param: eventTime Statistics of event time seen in this batch. It may contain the following keys:

                   "max" -> "2016-12-05T20:54:20.827Z"  // maximum event time seen in this trigger
                   "min" -> "2016-12-05T20:54:20.827Z"  // minimum event time seen in this trigger
                   "avg" -> "2016-12-05T20:54:20.827Z"  // average event time seen in this trigger
                   "watermark" -> "2016-12-05T20:54:20.827Z"  // watermark used in this trigger
   

All timestamps are in ISO8601 format, i.e. UTC timestamps. param: stateOperators Information about operators in the query that store state. param: sources detailed statistics on data being read from each of the streaming sources.