PQ69792: CHANGE JVM_LOGFILE USAGE | |||||||||||||||||||||||||
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APAR status Closed as documentation error. Error description Change/clarify documentation on the usage of JVM_LOGFILE as it only works with JVM_DEBUG=1 and not JVM_ENABLE_VERBOSE_GC=1. JVM_DEBUG=1 setting only puts out JNI and class debug messages redirected to this logfile and not Garbage Collection (GC) output.Local fix If you need Garbage Collection (GC) output in an output file, you will need to use IBM_JVM_ST_VERBOSEGC_LOG along with JVM_ENABLE_VERBOSE_GC=1 set in the server's current.env. Note: Recommend NOT to use the same filename for both JVM_LOGFILE and IBM_JVM_ST_VERBOSEGC_LOG as one will overwrite the other.Problem summary **************************************************************** * USERS AFFECTED: All users of WebSphere Application Server * * V4.0.1 for z/OS and OS/390 * **************************************************************** * PROBLEM DESCRIPTION: Text in the WebSphere for z/OS books * * Installation and Customization, and * * Assembling J2EE Applications, needs to * * be updated to clarify the type of * * output collected in the file specified * * by the environment variable * * JVM_LOGFILE. This file does not * * contain garbage-collection output. * **************************************************************** * RECOMMENDATION: * **************************************************************** WebSphere for z/OS Installation and Customization, and Assembling J2EE Applications, both contain a description of the environment variable JVM_LOGFILE. This description needs to clearly state that, if specified, this file will contain only JNI and class debug messages, not garbage-collection output.Problem conclusion APAR PQ69792 requires changes to documentation. To access the latest online documentation, go to the product library page at: www.ibm.com/software/webservers/appserv/zos_os390/ WebSphere Application Server V4.0.1 for z/OS and OS/390 Installation and Customization (GA22-7834-06) will be changed as follows: "Appendix A. Environment and JVM properties files" Topic "Environment variable use" "Table 49. Where to use environment variables" on page 396 will be updated with the new entry for property "IBM_JVM_ST_VERBOSEGC_LOG=" which is optional for the System Management server instance and for J2EE business application server instances. "Appendix A. Environment and JVM properties files" Topic "Environment variable descriptions" on page 404 will be updated with the following new or changed variable descriptions: IBM_JVM_ST_VERBOSEGC_LOG=filename Specifies the HFS file in which garbage-collection output will be logged. Use this variable with both of the following: - JVM_ENABLE_CLASS_GC=1 to enable garbage collection, and - JVM_ENABLE_VERBOSE_GC=1 to view verbose output from the garbage collection. Recommendation: If you also are using the JVM_LOGFILE variable to specify an HFS file for JVM-related output, do not specify the same HFS file for the IBM_JVM_ST_VERBOSEGC_LOG variable. WebSphere for z/OS will not append data to an existing file; instead, the data will be overwritten if both of these variables specify the same HFS file. JVM_DEBUG=1 This option is equivalent to the ?verbose:class,jni Java invocation option. It reroutes JNI and class debug messages to SYSOUT for debugging purposes. Set JVM_DEBUG=1 to invoke JVM messaging. Note: Setting this variable does not result in garbage collection processing; to enable garbage collection, you must specify JVM_ENABLE_CLASS_GC=1. JVM_ENABLE_CLASS_GC=1 Enables garbage collection of class objects when this environment variable is set to the value 1. Without this setting, garbage collection is not enabled for class objects, so the default behavior is equivalent to the -Xnoclassgc Java invocation option. If you need garbage-collection output in an output file, specify the filename through the IBM_JVM_ST_VERBOSEGC_LOG environment variable. Otherwise, garbage-collection output appears in SYSOUT for the server region. JVM_ENABLE_VERBOSE_GC=1 Sets verbose garbage collection on or off. The value 1 is required for enabling garbage collection messages. This option is equivalent to the -verbose:gc Java invocation option. If you need garbage-collection output in an output file, specify the filename through the IBM_JVM_ST_VERBOSEGC_LOG environment variable. Otherwise, garbage-collection output appears in SYSOUT for the server region. JVM_LOGFILE=filename Specifies the HFS file in which JNI and class debug messages from the JVM will be logged. Recommendations: - Use this variable only in a single-server environment. If you use JVM_LOGFILE in a multiple-server environment, all the servers write to the same file, so you might have difficulty using the file for diagnostic purposes. In a multiple-server environment, use JVM_DEBUG=1 to direct JNI and class debug messages to the SYSOUT for a specific server. - This logfile does not contain garbage-collection output. If you enable garbage collection by specifying JVM_ENABLE_CLASS_GC=1, the output appears in SYSOUT for the server region, or in an HFS file you specify through the IBM_JVM_ST_VERBOSEGC_LOG environment variable. Do not specify the same HFS file for the IBM_JVM_ST_VERBOSEGC_LOG variable as you do for the JVM_LOGFILE variable. WebSphere for z/OS will not append data to an existing file; instead, the data will be overwritten if both of these variables specify the same HFS file. WebSphere Application Server V4.0.1 for z/OS and OS/390 Assembling J2EE Applications (SA22-7836-05) will contain identical changes to the corresponding table and environment variable descriptions in Appendix A: - "Table 23. Where to use environment variables" on page 269 - "Environment variable descriptions" on page 275Temporary fix Comments
APAR is sysrouted FROM one or more of the following: APAR is sysrouted TO one or more of the following: Modules/Macros
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Document Information |
Product categories: Software > Application Servers >
Distributed Application & Web Servers > WebSphere Application
Server for z/OS
Operating system(s):
Software version: 401
Software edition:
Reference #: PQ69792
IBM Group: Software Group
Modified date: Feb 27, 2003
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