WebCenter Content: "Content Server Request Failed - Failure to modify user credentials. There are no connections available from pool for provider 'SystemDatabase'. Unable to execute service method 'getConnection'. "

Recently in our WebCenter Content (WCC, earlier termed as Enterprise Content Management), we starting getting an error in the login page.  Error details are the following:

Content Server Request Failed
 
 Failure to modify user credentials. There are no connections available from pool for provider 'SystemDatabase'. Unable to execute service method 'getConnection'. weblogic.jdbc.extensions.PoolLimitSQLException: weblogic.common.resourcepool.ResourceLimitException: No resources currently available in pool CSDS to allocate to applications, please increase the size of the pool and retry...

Nothing had changed in the environment, I tried restarting the Admin and Managed Services. It didn't help. After doing some google and oracle forums, I got a hint what could fix the issue. 

Solution:

Weblogic  Console> Datasources 

It will show you the "Summary of JDBC Data Sources"  with two tabs -  Configuration and Monitoring. You can click on Monitoring tab to see the "state" column for the datasources. If it is overloaded, go back to configuration tab. In my case the datasource 'CSDS' was overloaded.

1. Select 'CSDS'  and then click on 'Lock & Edit'. You can see many tabs  like Configuration,Targets, Monitoring, Control, Security, Notes. 

2. In the 'Configuration' tab, select the sub-tab 'Connection Pool'.

3. The value for "Maximum Capacity:" was 25 and I changed it to 30, saved the changed and activated the update. This change do not need services to be bounced.

Maximum capacity is the maximum number of physical connections that this connection pool can contain.

Within a minute, I was able to get the Content Server Login page. I verified the Datasource monitoring and the state got changed to 'Running'.

Reference:
http://www.albinsblog.com/2012/10/resourcelimitexception-no-resources.html