KB-1796 Tomcat fails to deploy Appian with "java.lang.ClassNotFoundException: com.mysql.jdbc.Driver" error

Symptoms

Tomcat fails with the following error in <APPIAN_HOME>/logs/tomcat-stdOut.log:

WARNING [localhost-startStop-1] org.apache.naming.NamingContext.lookup Unexpected exception resolving reference
java.sql.SQLException: Cannot load JDBC driver class 'com.mysql.jdbc.Driver'
at org.apache.tomcat.dbcp.dbcp2.BasicDataSource.createConnectionFactory(BasicDataSource.java:2203)
.
.
Caused by: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver

Cause

The database driver was not copied over to <TOMCAT_HOME>\tomcat\apache-tomcat\lib\.

Action

Copy the database driver to <TOMCAT_HOME>\tomcat\apache-tomcat\lib\ as discussed in this step of the Appian installation guide.

Affected Versions

This article applies to Appian 18.3 and later.

Last Reviewed: November 2018