PMM QAN Only Shows USE and BEGIN Queries in Percona XtraDB Cluster, Application Queries Not Visible

Percona Monitoring and Management (PMM) PMM 2.x
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1

Hello,

I’m currently using Percona Monitoring and Management (PMM) to monitor a Percona XtraDB Cluster. However, I’m facing an issue where the Query Analytics (QAN) only displays USE and BEGIN queries, and I cannot see the application queries, including their response times.



Here are the details of my setup:

- **PMM Configuration:**

pmm-admin add mysql --username=pmm --password=secret --query-source=perfschema

- **MySQL Grants:**

SHOW GRANTS FOR 'pmm'@'%';
+------------------------------------------------------------------------------+
| Grants for pmm@%                                                             |
+------------------------------------------------------------------------------+
| GRANT SELECT, RELOAD, PROCESS, SUPER, REPLICATION CLIENT ON *.* TO `pmm`@`%` |
| GRANT BACKUP_ADMIN ON *.* TO `pmm`@`%`                                       |
+------------------------------------------------------------------------------+
  • Version:
    mysql  Ver 8.0.36-28.1 for Linux on x86_64 (Percona XtraDB Cluster (GPL), Release rel28, Revision bfb687f, WSREP version 26.1.4.3)

I have another Percona XtraDB Cluster with a similar configuration, and on that setup, I can see all application queries along with their response times in QAN.

I would appreciate any guidance on why this might be happening and how I can resolve it to see the application queries in PMM QAN.

Thank you!

2

Hi,

Are the mysql settings the same? Like performance_schema is enabled on both cluster etc… ? Because it looks like your pmm is using performance_schema for queries. You can share the config for both cluster.

4

The Performance Schema is enabled on both clusters, as shown in the output. I forgot to mention this earlier. Thank you!

mysql> SHOW VARIABLES LIKE ‘performance_schema’;
±-------------------±------+
| Variable_name | Value |
±-------------------±------+
| performance_schema | ON |
±-------------------±------+
1 row in set (0.01 sec)

5

Check the performance_schema.events_statements* tables. Do you see queries there? If not, then the problem is with perf schema, not PMM. PMM only reads what it can.

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