chore(mariadb): increase max_connections to 1024

[skrobul]

No description provided.

[cardoe]

Any other tweaks or how do we know what's the right value?

[skrobul]

We do not know for sure that it would be sufficient long term, but we know that the default of 150+1 is not enough for production environment where we run multiple replicas of neutron, nova and other openstack services. The high level watermark there is already over the limit:

❯ kubectl --context uc_dfw3_prod -n openstack exec -it mariadb-0 -- bash -c "mariadb -u root -p\$MARIADB_ROOT_PASSWORD -e 'show status like \"max_used_connections%\";'"
+---------------------------+---------------------+
| Variable_name             | Value               |
+---------------------------+---------------------+
| Max_used_connections      | 156                 |
| Max_used_connections_time | 2025-04-08 06:12:19 |
+---------------------------+---------------------+

☸ uc_iad3_staging (openstack) in undercloud-deploy/ansi

I am not too worried about getting this value perfectly right at this time because it's a temporary change. Once we figure out how to safely migrate to HA method and adjust applications to leverage multiple nodes, the demand for max_connections will be smaller.

[skrobul]

other environments for reference:

❯ kubectl --context uc_iad3_staging -n openstack exec -it mariadb-0 -- bash -c "mariadb -u root -p\$MARIADB_ROOT_PASSWORD -e 'show status like \"max_used_connections%\";'"
+---------------------------+---------------------+
| Variable_name             | Value               |
+---------------------------+---------------------+
| Max_used_connections      | 122                 |
| Max_used_connections_time | 2025-04-07 16:11:02 |
+---------------------------+---------------------+

☸ uc_iad3_staging (openstack) in undercloud-deploy/ansible on  staging-bonds [$?] via 🐍 v3.12.8 
❯ kubectl --context uc_iad3_dev -n openstack exec -it mariadb-0 -- bash -c "mariadb -u root -p\$MARIADB_ROOT_PASSWORD -e 'show status like \"max_used_connections%\";'"
+---------------------------+---------------------+
| Variable_name             | Value               |
+---------------------------+---------------------+
| Max_used_connections      | 90                  |
| Max_used_connections_time | 2025-03-20 04:21:16 |
+---------------------------+---------------------+

☸ uc_iad3_staging (openstack) in undercloud-deploy/ansible on  staging-bonds [$?] via 🐍 v3.12.8 
❯