MV_TRACE_EVENTS_STATUS

The MV_TRACE_EVENTS_STATUS information schema view can be used to view the status of current trace events. The ALTER TRACE permission is required to query MV_TRACE_EVENTS_STATUS.

The LMV will return a row for each trace event that either:

  1. Has at least one entry in the buffer  -- or --

  2. Is currently active

This means that trace events that are disabled and have no more entries in the buffer will not show up in the LMV. The CREATION_TIME and CONFIGURATION columns always return NULL whenever ACTIVE is NO.

This view also has two columns, TOTAL_EVENTS_TRACED and UNCONSUMED_EVENTS used to track total events traced since creation time and total events that were evicted without having been retrieved since creation time. This provides an approximation for event loss rate that assists with determining the appropriate size for the ring buffer as well as appropriate event tracing configuration and appropriate "polling" rate from MV_TRACE_EVENTS.

Column Name

Description

Column Type

NODE_ID

The ID of the SingleStore node

bigint(4)

NODE_IP

The IP address of the SingleStore node

varchar(256)

NODE_TYPE

The type of node: master aggregator (MA), child aggregator (CA), or leaf node (LEAF)

varchar(256)

EVENT_TYPE

The type of event that is traced, where Query_completion is currently the only available event type.

varchar(256)

ACTIVE

If the trace event is active

varchar(4): YES/NO

CREATION_TIME

The time the event configuration was created

datetime(6)/NULL

CONFIGURATION

The way the user configured it in the WITH(...) list, presented in JSON format

json/NULL

CURRENT_MEMORY_USAGE_B

Current memory, in bytes, used by all event traces of this EVENT_TYPE

bigint

TOTAL_EVENTS_TRACED

Total number of events traced of this EVENT_TYPE

bigint

UNCONSUMED_EVENTS

Total number of events of EVENT_TYPE that were evicted before ever having been consumed (i.e. by querying MV_TRACE_EVENTS)

bigint

Last modified: December 19, 2023

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