Known problems and workarounds

Assume a database instance is managed by HP-UX WLM. If WLM starts before that instance, it sets the CPU allocation for the instance’s workload group based on the mincpu and maxcpu values in the WLM configuration file. The instance’s workload group remains at that initial CPU allocation until the instance starts, allowing wlmoradc to gather metrics on it and pass the metrics to WLM.

Try to minimize the time between WLM start-up and instance start-up.

wlmoradc provides minimal checking of the SQL it passes to SQL*Plus. If SQL*Plus finds problems with the SQL statements, messages are sent to syslog or stderr. In some cases, SQL*Plus cannot execute the statements, resulting in a warning and a reported execution time (walltime) of 0 seconds.

To avoid such events, always verify your SQL by hand before finalizing your WLM and wlmoradc configuration files.

If wlmoradc detects a command-line error and debugging is enabled, the code reported by clean_exit may not be useful. For example:

Mar 26 22:57:16 mytestmachine WLMTK: wlmoradc[p8686] INFO starting wlmoradc
Mar 26 22:57:16 mytestmachine WLMTK: wlmoradc[p8686] ERROR bad oracle home passed to -h or --home argument
Mar 26 22:57:16 mytestmachine WLMTK: wlmoradc[p8686] INFO ending wlmoradc
Mar 26 22:57:16 mytestmachine WLMTK: wlmoradc[p8686] DEBUG clean_exit with exit value:Not a typewriter

If the ERROR message and the DEBUG message disagree, ignore the DEBUG message.

If you use the ApacheTK tool time_url_fetch with a URL that Apache cannot serve (such as http://mytestmachine/misspelllllled_url.htm) the ab tool and time_url_fetch report the elapsed time for Apache to serve up a “Not found” msg. Neither tool considers this an error, although an individual trying to access this URL might.

Always check your target URL by hand with your browser, the ab tool, or the time_url_fetch tool to ensure you are really getting a page fetch.

In the “Using HP-UX Workload Manager with Apache” white paper, in section 13.4.0.7, the step using pig.pl to generate load, namely:

may produce error messages and not generate the desired load. The errors in /opt/hpws/apache/logs/error_log or /opt/hpws/apache/logs/error_log2 are of the form:

     [Sun Dec 14 16:03:08 2003] [error] 13441: ModPerl::Registry: No
     comma allowed after filehandle at /opt/hpws/apache/cgi-bin/pig.pl
     line 26.

or possibly:

     [Sun Dec 14 18:02:40 2003] [error] 14688: ModPerl::Registry: Can’t
     locate Apache.pm in @INC
     <remainder of message removed>

These errors indicate that the Apache environment has issues with the example mod_perl workload pig.pl.

Use a different mod_perl workload that you know works with your Apache environment. Alternatively, focus on the .cgi and .php example workloads used in the same section of the white paper.

Monitoring a WebLogic instance with wlmwlsdc can produce a javax/security/auth/callback/CallbackHandler error.

In particular, running the wlmwlsdc data collector with a single argument:

% /opt/wlm/toolkits/weblogic/bin/wlmwlsdc \ /home/wladmin/wlm/myinstA.props

on a version of WebLogic other than 7.0 can produce the following error:

Exception in thread "main" java.lang.NoClassDefFoundError:
javax/security/auth/callback/CallbackHandler
     at weblogic.jndi.Environment.getContext(Environment.java:164)
     at weblogic.jndi.Environment.getInitialContext(Environment.java:143)
     at weblogic.management.Helper.getMBeanHomeForName(Helper.java:94)
     at weblogic.management.Helper.getMBeanHome(Helper.java:59)
     at com.hp.wrm.tk.weblogic.ExecQueueFetcher.connect2localhome(ExecQueueFetcher.java:328)
     at
com.hp.wrm.tk.weblogic.ExecQueueFetcher.fetch(ExecQueueFetcher.java:224)
     at com.hp.wrm.tk.DataCollector.run(DataCollector.java:355)
     at com.hp.wrm.tk.DataCollector.run(DataCollector.java:434)
     at
com.hp.wrm.tk.weblogic.ExecQueueDataCollector.main(ExecQueueDataCollector.java:67)

This message occurs when the WL_HOME environment variable has been set to override wlmwlsdc’s default, but wlmwlsdc is using a JAVA_HOME variable set to /opt/java1.3, which is not supported by WebLogic 8.1.

Provide a setting for both JAVA_HOME and WL_HOME when using WLS 8.1.

There are two ways for settings these variables, as explained below:

For more information on the possible settings and security considerations for this shell file, see the white paper Using HP-UX Workload Manager with BEA WebLogic Server, section “12.1.4 wlmwlsdc POSIX environment variable scripts”. The paper is available from the following location in the “information library:”

http://www.hp.com/go/wlm

It is installed on your system at:

/opt/wlm/toolkits/weblogic/doc/weblogic_wlm_howto.html