Bug #42105 EXPLAIN/example query is not always shown for queries with > 500ms runtimes

• Submitted: 14 Jan 11:25
• Modified: 30 Jun 14:15
• Reporter: Mark Leith
• Status: Verified
• Category: Monitoring: Agent
• Severity: S3 (Non-critical)
• Version: 2.0.1.7125
• OS: Any
• Assigned to: Jan Kneschke
• Triage: Needs Triage: D3 (Medium) / R4 (High) / E4 (High)

[14 Jan 11:25] Mark Leith

Description:
EXPLAIN plans are not always shown for queries that run for greater than 500
milliseconds, as the EXPLAIN may have been purged with the work done on keeping memory
usage to a minimum, or due to backlogs/delays in the server asking for the data. 

How to repeat:
No reliable test case as yet, however, running a lot of statements through Query Analysis
with auto-EXPLAIN enabled should result in a number of the statements not getting an
EXPLAIN plan within the statement popups within the Dashboard.

Suggested fix:
The JSON protocol should fix this, as the data would not be purged before being sent.

[14 Jan 16:00] Mark Leith

This also happens with the example query text too.

[6 Mar 20:55] Mark Leith

Bug #43212 was marked as a duplicate of this one.

[30 Jun 14:15] Enterprise Tools JIRA Robot

Jan Kneschke writes: 
it is really accepted.

[30 Sep 21:24] Enterprise Tools JIRA Robot

Mark Matthews writes: 
There is a possibility to fix this without JSON/REST but by letting the slot count for
examples and explains be varied by the service manager, or when the agent notices that
things will be "overrun"?