Here are some settings that should improve the interaction to the DB.
Minimum Pool Size: 0 – in production, this should normally be 0. This avoids errors due to stale connections. Having this set to 1 is why “It seems the adapters is not releasing the connection once it is done.” You configured the pool to keep one at all times. Also, it can have up to 10 connections in the pool. If you don’t want a pool, disable pooling.
Maximum Connections: N – you’ll want to tweak this for your environment. 10 may be a good start, depending upon load, activity, etc.
Block Timeout (msec): 60000 – 1000 (1 second) is far too short. This controls how long a thread in IS will wait for connection from the pool when IS is busy.
Expire Timeout (msec): (set to 1 - 5 minutes less than the DB timeout setting) – 1000 (1 second) is far, far too short. This can cause session thrashing on the DB. You want IS to timeout the connection before the DB does so that IS doesn’t try to use a stale connection (which will cause errors in your integration).
#webMethods#Integration-Server-and-ESB#Adapters-and-E-Standards