KB-2032 Tomcat fails to start with "Connection has been abandoned" warning

Symptoms

Tomcat is not able to start after changes have been made to <APPIAN_HOME>/conf/tomcat-resources.xml. The following error can be seen in the application server log:

WARNING [Tomcat JDBC Pool Cleaner[xxxxxxxxxx:xxxxxxxx]] org.apache.tomcat.jdbc.pool.ConnectionPool.abandon Connection has been abandoned PooledConnection[com.xxx.xxx.xxx.xxx]:java.lang.Exception

Cause

This issue occurs when <APPIAN_HOME>/conf/tomcat-resources.xml has the below properties set:

removeAbandoned="true"
removeAbandonedTimeout="30"
logAbandoned="true"

Action

Set removeAbandoned="false" or remove the properties listed in the cause from tomcat-resources.xml.

The Configuring Relational Databases documentation contains recommendations on which properties should be set in tomcat-resources.xml.

Affected Versions

This article applies to Appian 18.3 and later.

Last Reviewed: December 2019