Appian and Apache start successfully, but a HTTP 500 Internal Server Error appears when trying to access the Appian login page.
The <APACHE_HOME>/logs/mod_jk.log file shows the following error:
[info] init_jk::mod_jk.c (3595): mod_jk/1.2.42 initialized[info] jk_handler::mod_jk.c (3003): Could not find a worker for worker name=LoadBalancer”
The JKWorkerProperty fields configured in Configuring Apache Web Server with Appian under Setup Worker Properties are specified in a file outside <APACHE_HOME>/conf/httpd.conf, rather than directly within it. Apache documentation indicates this is possible with the JkWorkersFile directive referencing a separate file called workers.properties, which contains the JKWorkerProperty fields.
However, the JkWorkersFile directive doesn't include the contents of workers.properties within httpd.conf. Trying to reference any worker names specified by the JKWorkerProperty field worker.list within httpd.conf will fail, causing the error in mod_jk.log.
Follow the Appian Documentation Configuring Apache Web Server with Appian under Setup Worker Properties (or Configuring Apache Web Server with Jboss in 18.2 and below) when configuring the JKWorkerProperty fields. 1) Remove the line using the JkWorkersFile directive: JkWorkersFile /path/to/workers.properties. 2) Directly add the contents of workers.properties to httpd.conf.
Instead of following the action steps, add the line Include conf/workers.properties after the line JkWorkerFile /path/to/workers.properties in httpd.conf.
This article applies to Appian 17.1 and later using Apache as a web server.
Last Reviewed: October 2018
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