In any –ds.xml files used by ATG, edit the <min-pool-size> and <max-pool-size> settings to reflect the expected maximum number of simultaneous connections.

Note: Your file may have a different name or location, depending on your configuration.

<min-pool-size>50</min-pool-size>
<max-pool-size>75</max-pool-size>

Datasource connections can be monitored using the JMX-Console at:

http://hostname:port/jmx-console

Look for ATG and ManagedConnectionFactory. The MBean monitor page shows how many connections exist and how many are being used.