Setting up a Metric Server
 Technote (FAQ)
 
Problem
Metric Server is a system monitoring component of Load Balancer, used to provide system load information to the Dispatcher machine. It can be used with the following components: Dispatcher, Site Selector, Cisco CSS Controller, and the Nortel Alteon Controller
 
Cause
The intent of this document is to help guide and explain how to setup Metric Server.
 
Solution
  1. On the back-end servers, install the Metric Server package from the Load Balancer install (this does NOT require a license file).

  2. On the Load Balancer machine, create a key file (using lbkeys create command). via command line, type:

    lbkeys create<enter>

    LB does not have to be running for this command to execute. This will create a number of key files, located in the following directory: <edge install>/edge/lb/admin/keys/

  3. Copy the resulting key file from step 2, (dispatcher-YOUR_IP_ADDRESS-10099.key) to the ...ibm/edge/lb/admin/keys directory on the back-end server machine(s). Verify that the key file's permission's enable the file to be readable by the root.

  4. The RMI port value specified on the back-end servers, must be the same value as the RMI port value for the Metric Server on the Load Balancer machine. Check the metricserver scripts on all machines in the /usr/bin directory to verify that the same port number is being used. The variable is "RMI_PORT"

  5. On the Load Balancer side
    Start dsserver.
    Add your cluster/ports/servers
    Issue command:

    dscontrol manager start manager.log port

    "port" is the RMI port chosen for all the Metric Server agents to run on. The default RMI port that is set in the metricserver script file is 10004.

    Issue command:

    dscontrol metric add cluster:systemMetric

    "systemMetric" is the name of the script (residing on the back-end server) which should run on each of the servers in the configuration under the specified cluster (or site name). Two scripts are provided - cpuload and memload.

    (Add to the configuration only servers that contain a Metric Server agent running on the port specified in the metricserver file. )

  6. On the back-end servers, start metric server by issuing: metricserver<enter>

  7. To see if we are getting values, on the Load Balancer machine issue "dscontrol manager report" and check the last column.

Note: When gathering metrics across different domains, you must explicitly set the java.rmi.server.hostname in the server script (dsserver, cbrserver, etc) to the fully-qualified domain name (FQDN) of the machine that is requesting the metrics. This is necessary because, depending on your setup and operating system, InetAddress.getLocalHost.getHostName() might not return the FQDN.

Note: When two or more metrics are gathered and normalized for each server into a single system load value, rounding errors may occur.

WLM Restriction
Like the WLM advisor, the Metric Server reports on server systems as a whole, rather than on individual protocol-specific server daemons. Both WLM and Metric Server place their results into the system column of the manager report. As a consequence, running both the WLM advisor and Metric Server at the same time is not supported.

Is it working?
if the answer is no, check the following:
try adding the fully qualified domain name to the hosts file on the back-end servers
confirm the RMI port is correct
confirm that the key file has been transferred to the proper directory
confirm that the key file is not corrupt, may want to recreate and copy again
make sure no firewall software is blocking the communication

If its still not working, follow this technote when gathering the required doc:

http://www.ibm.com/support/docview.wss?rs=180&uid=swg21141087
 
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers WebSphere Application Server Edge Component AIX, HPUX, Linux, Solaris, Windows 6.0, 6.0.1 Base, Express, Network Deployment
 
 


Document Information


Product categories: Software > Application Servers > Edge Servers > WebSphere Edge Server > Load Balancer
Operating system(s): HP-UX
Software version: 6.0.1
Software edition:
Reference #: 1210855
IBM Group: Software Group
Modified date: Jun 30, 2005