We have a JDBC connection set up for Sybase 17.
There is a Polling Notification.
Whenever the notification picks up a record from buffer table, it publishes the notification document and trigger invokes the subscription service.

The subscription service then uses SELECT adapter service to fetch record from the transaction table.
Whilst performing this activity, many a times few calls fails with below error:
(JZ0C0/0) JZ0C0: Connection is already closed."
JZ0C0: Connection is already closed.

Records are getting populated in the buffer table quite frequently, because of which the JDBC connection may be used by many parallel executions of the subscription service.

I have set below pool settings for the JDBC connection:
|Enable Connection Pooling|true|
|Minimum Pool Size|1|
|Maximum Pool Size|1000|
|Pool Increment Size|1|
|Block Timeout (msec)|10000|
|Expire Timeout (msec)|10000|

Kindly assist with optimal settings to ensure this error does not occur.

Thanks & Regards,
Khushaboo Shandilya

Please set MinPoolSize to Zero (“0”). This will avoid stale connections depending on network issues.
Other optimizations will be the result of furthert testing.

Hello Holger,

I have updated Min Pool Size to ‘0’.
Did not see any error since then.
But, will keep monitoring.

Thank you so much for your help!

Thanks & Regards,
Khushaboo Shandilya

Hi Khusbaboo,

As Holger mentioned. Keep minimum pool size 0 and if issue is reproducible in lower environment then only try to validate if reducing Block timeout by two zero’s is solving the problem.

Regards,
Kuldeep Gupta

Hello Kuldeep,

Setting Min Pool Size to 0 seems to have solved the issue.
But, if it comes up again, will try reducing the Block Timeout as you recommended.

Thanks!

Regards,
Khushaboo Shandilya

Glad to hear