Excessive "reliable Message" waits seen on RAC after a few days uptime
(Doc ID 1990796.1)
Last updated on MARCH 12, 2021
Applies to:Oracle Database - Enterprise Edition - Version 184.108.40.206 to 220.127.116.11 [Release 12.1]
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Backup Service - Version N/A and later
Information in this document applies to any platform.
"reliable message" waits can exceed 1 second.
This is for a 18.104.22.168 database (non-pluggable).
The problem does not manifest until a few days of up-time
The only workaround is to restart the instance.
Performance is affected severely for example a truncate command can take 20 minutes or more and AWR reports show high wait time for "reliable message".
A hang analyze will also show
service name: SYS$BACKGROUND
Current Wait Stack:
1: waiting for 'CSS group membership query'
CSS group membership query's are not processed fast enough because of congestion.
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