Bug #102165 mysqlrouter process regularly increasing mem size by 64MB approx every 8-9 hours
Submitted: 6 Jan 2021 14:40 Modified: 6 Jan 2021 15:13
Reporter: MATTHEW GOTT Email Updates:
Status: Duplicate Impact on me:
None 
Category:MySQL Router Severity:S3 (Non-critical)
Version:8.0.21 OS:Red Hat (6.10)
Assigned to: CPU Architecture:x86 (VMs on RHEV)

[6 Jan 2021 14:40] MATTHEW GOTT 
Description:
Issue occurring on multiple environments.
Each environment consists of:
- 3 DB servers running InnoDB cluster MySQL 5.7.31
- Multiple application servers running MySQL Router 8.0.21
- Each application server running 1 Java client and 2 to 8 Jboss 7.1.5 instances, connecting to database via localhost MySQL Router port 6446.
Total memory used by mysqlrouter tracked using pmap every minute.
In one environment (2 Jboss instances), this is increasing by 64MB every 8 hours 25 mins. Application traffic very limited in this instance.
In the other environment (8 Jboss instances), it is increasing every 9 hours 5 mins. Application traffic very high in this environment.
mysqlrouter logging level increased to DEBUG in first environment, but no log entry identifiable as coinciding with time of memory increase.
strace also captured through one of the increases, which shows mmap of 128MB immediately followed by an munmap of 64MB - hence net increase is 64MB.

How to repeat:
Currently assessing if behaviour is repeatable even with no DB clients connected/connecting.
[6 Jan 2021 15:03] MySQL Verification Team 
Thank you for the bug report. Duplicate of https://bugs.mysql.com/bug.php?id=101779.
[6 Jan 2021 15:13] MATTHEW GOTT 
Thanks.
I created a new bug report as frequency and size of the memory increases was different to that originally reported on #101779. Also original reporter hadn't replied to questions for a month, so it had been put on status of "No feedback" and automatically suspended.
Which bug will be investigated/progressed now that one is "No feedback" and the other is "Duplicate"?
[6 Jan 2021 16:22] MySQL Verification Team 
I opened that bug so the assignment to check this bug too.