Post ACS upgrade getting error "Unable to load db configuration".

[GerorgeEG]

problem

We have upgrade the ACS from 4.19.1.2 to 4.20.2.0 and after that Apache CloudStack is giving "HTTP ERROR 503 Service Unavailable"
We verified ACS database is up but ACS management server is not able to connect to database. Below is the error
WARN [c.c.u.d.T.Transaction] (main:[]) (logid:) Unable to load db configuration, using defaults with 5 connections. Falling back on assumed datasource on localhost:3306 using username:password=cloud:cloud. Please check your configuration com.zaxxer.hikari.pool.HikariPool$PoolInitializationException: Failed to initialize pool: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
`me:password=cloud:cloud. Please check your configuration com.zaxxer.hikari.pool.HikariPool$PoolInitializationException: Failed to initialize pool: Could not create connection to database server. Attempted reconnect 3 times. Giving up.

    at com.zaxxer.hikari.pool.HikariPool.throwPoolInitializationException(HikariPool.java:584)

2026-04-16 02:30:50,423 ERROR [c.c.u.d.Merovingian2] (main:[]) (logid:) Unable to get a new db connection java.sql.SQLTransientConnectionException: cloud - Connection is not available, request timed out after 1000ms (total=0, active=0, idle=0, waiting=0)
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

    at jdk.internal.reflect.GeneratedConstructorAccessor31.newInstance(Unknown Source)

    at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)

    at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:500)

    at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:481)

    at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:62)

    at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)

    at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:150)

    at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:166)

    at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:89)

    at com.mysql.cj.NativeSession.connect(NativeSession.java:121)

    at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:945)

    at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:815)

    ... 13 more

Caused by: java.net.ConnectException: Connection refused

    at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)

    at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:150)

    at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:166)

    at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:89)

    at com.mysql.cj.NativeSession.connect(NativeSession.java:121)

    at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:945)

    at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:815)

    ... 13 more

Caused by: java.net.ConnectException: Connection refused

`

versions

ACS Version pre-upgrade : 4.19.1.2
ACS version post-upgrade : 4.20.2.0

Management and DB OS : RHEL 8
DB : MariaDB Galera Cluster

We have been able to upgrade other 3 environment installed with same configuration but this upgrade is getting failed

The steps to reproduce the bug

...

What to do about it?

No response

[andrijapanicsb]

MariaDB driver - test connections using the mentioned credentials (from mgmt to DB server)

telnet to port 3306 (network check)
auth as cloud:cloud from mgmt to DB server

Check if the MariaDB drivers maybe got updated.

[andrijapanicsb]

Which MariaDB version?

[GerorgeEG]

MariaDB version is 10.3.39 , we have verified DB is up and accessible when we are getting this error.