Troubleshooting
Problem
A Metric Server is a system monitoring component of the WebSphere Load Balancer. The Metric Server component is used to provide system load information to the Load Balancer. It can be used with any of the Load Balancer components: Dispatcher, Site Selector, or Content Based Routing.
Cause
The intent of this document is to help supplement existing Metric Server information. Original Metric Server documentation is available in the Administration Guide.
Resolving The Problem
If metrics are enabled as part of the Load Balancer's weight calculation, the Metric Server Agent must be installed on all servers in a defined cluster of the Load Balancer. By default, metrics are enabled on the Site Selector component but disabled on the Dispatcher and CBR components.
Installation of the Metric Server Agent:
On the back-end servers, install the Metric Server package from the Load Balancer installation package.
- Using IBM Installation Manager, select install and select the IBM WebSphere Edge Components: Load Balancer for IPV4 and IPv6.
- Accept the terms of the license agreement
- Modify the installation location (optional). Select Next.
- Metric Server contains no translations. Select Next on the Translations window.
- The Metric Server component is not selected by default. On the features window, select Metric Server and clear the Dispatcher selection.
- Select Next. Select Install.
- When the installation completes, a reboot is necessary on the Windows operating system.
Key file generation:
The Metric Server uses secured connections to communicate with the Metric Agents. Key files must be generated. The public key file must be copied to the Metric Server Agent machine before Metric Server is started on the agent workstation. Key file generation instructions are provided in the Administration Guide.
Before the key file is generated for the Dispatcher component, the dsserver script must be modified. The modification must persist while Metric Server is in use. Do not restore the file to the original setting. The dsserver script is overwritten when fix packs are applied. After a fix pack is applied to the Load Balancer Dispatcher component, modify the dsserver script. The key files do not need to be regenerated. Required modification for the Dispatcher component is provided in step 6 in the Administration Guide.
Verification:
To verify that metrics are collected by the Load Balancer, issue view the manager report The last column is the value for the metrics obtained from the Metric Agent.
Troubleshooting:
If the value shows a metric of -1, the metric collection failed. Stop the metric agent on the backend server by using the "metricserver stop" command. Windows users can stop the IBM WebSphere Metric Server service to stop the Metric Server Agent. Edit the metricserver script and change the LOGLEVEL value from 1 (minimal) to 5 (verbose). Restart the Metric Server Agent and examine the contents of the agent.log file.
If the value shows a metric of -1, the metric collection failed. Stop the metric agent on the backend server by using the "metricserver stop" command. Windows users can stop the IBM WebSphere Metric Server service to stop the Metric Server Agent. Edit the metricserver script and change the LOGLEVEL value from 1 (minimal) to 5 (verbose). Restart the Metric Server Agent and examine the contents of the agent.log file.
If the log does not contain connection attempts from the Load Balancer, the failure occurs at the Load Balancer. Increase the loglevel setting of the Metric Server component at the Load Balancer by using the "manager metric set loglevel 5" command or the Configuration Settings of the Manager object on the graphical interface. Examine the Load Balancer metricserver.log file for the cause of the problem.
If its still not working, gather required documentation:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg21141087
Related Information
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Document Information
Modified date:
19 April 2022
UID
swg21210855