CAST Engineering Dashboard - Views - Errors - Apache Error 502

This page is a troubleshooting guide for the below error on dashboard :

Apache Error 502: There is a problem with the page you are looking for, and it cannot be displayed. When the webserver(while acting as a gateway or proxy) contacted the upstream content server, it received an invalid response from the content server

One of the cases where we have com across this error is when compute call graph button is clicked -

1. Launch Dashboard

2. Goto Cast Discovery Portal

3. Under Call Graph, click on “Compute Call graph”

1. Relevant  input
2. Update the schema statistics
3. Check for any external applications that are used to kill long web sessions
   
4. If relevant, use the following action: contact CAST Support with relevant input. For CAST support reproduce the problem

Update the schema statistics

For CSS - run CSS Optimization on the central Base & Knowledge Base. To do so you may refer to topic Optimizing CAST databases in this page

Check for any external applications that are used to kill long web sessions 

Check if you have installed any other applications/ plugins that are used to monitor the sessions/requests. This plugin/application might be killing the session/stopping the request. You need to either deactivate them or change the settings in order to add this request into the exception.  

If the above changes did not solve the issue, then go to next step

Relevant input

1. Sherlock export
2. Complete screenshots of the dashboard with URL showing the object name for which you are computing the call graph/performing any other action leading to 502 error
3. Tomcat version 
4. War deployed at your end 
5. Dashboard logs with SQL traces by following the page Configuring Dashboard to SQL trace 
6. Username used to login to dashboard.