Initial load of OneClick WebApp slow on load balancer

Products

• Spectrum
• Network Observability

Issue/Introduction

When accessing the OneClick WebApp through its load balanced front end, the Edge dev tools network inspector shows a 30s delay for the first resource to load (/spectrum/webapp). The app runs normally after that, but the server name at the bottom of the OC window remains localhost:8443

That behavior is not present when attempting to access the OneClick WebApp through the servers directly, bypassing the load balancer.

Environment

Spectrum: Any version

Resolution

1. Navigate to the $SPECROOT/tomcat/webapps/spectrum/WEB-INF location

2. Open the web.xml file in a text editor.

3. Locate the WebAppLaunchServlet section.

4. Add the following segment to WebAppLaunchServlet section:

<init-param>
<param-name>OCServerInLB</param-name>
<param-value>hostname/IP</param-value>
</init-param>

Put the OneClicks name in place of hostname/IP

For each OC host add the above section.

Stop/start the Spectrum Tomcat service to put the change in place.