#==============================================================================#          JVM Management MIB - Instrumentation Classes#============================================================================== In this directory:------------------ README:              this filecommands.env:        a file containing some ksh variables & functions                     that I have used to generate & compile all the                      stuff. Probably only valid in my own environment.logging.properties:  logging.properties file that can be used to obtain                     trace information.*.java:              utility and custom classes for the JVM Management MIB.                     These classes show how to provide instrumentation for                     a mibgen generated MIB, how to simulate virtual tables,		     and how to make use of the SnmpUserDataFactory.		     Only the jvmMemory group and its tables are instrumented. Dependency----------     jvmManagementMib.txt : the JVM Management MIB module in compilable form.    Tiger SNMP Runtime   : SNMP Runtime classes for Tiger. We assume these                           classes could be part of the JMX delivery                           (classes in com.sun.jmx.snmp.*)    JDMK 5.1 : The jdmktk.jar contains the com.sun.jdmk.tools.MibGen class               used to compile the MIB. JDMK also has a mibgen.sh script               to start mibgen. By default mibgen generates code that can               integrate with JDMK SNMP runtime. In order to generate               code that integrate with Tiger SNMP runtime, you need to	       start mibgen with a non-default resource file.                JDMK 5.1 workspace contains a mibgen resource file               specific for tiger: mibgen.property.tiger     Custom Instrumentation Code: the files in this directory. How to proceed:--------------- Get mibgen from JDMK 5.1. Start mibgen with mibgen resource file fortiger (add -Dcom.sun.jdmk.tools.mibgen.config.file=<mibgen.properties.tiger>)on the Java command line. Use mibgen to generate code for the jvmManagementMib.txt file. Note thatthe custom classes provided in this directory are all in the sun.management.snmp.jvminstr package, and expect the generated classes tobe in another sun.management.snmp.jvmmib package (use mibgen option -tp sun.management.snmp.jvmmib) If this package name does not suit you, simply change it to something else,both in the custom classes below (you might use 'sed' or do it manually) and in the -tp option that you will pass to mibgen. It is recommended to generate all classes in a different directory (ifyou read command.env you will see that I have put the custom classesin a "custom" directory, and the generated classes in a "parsed" directory. This makes it easier to cleanup the mib. You can safelydo a rm -rf <parsed> and call mibgen again. Then compile the generated classes - you will need JMX and Tiger SNMPruntime classes in your classpath - if you compile with a tiger build thatalready have them then you don't need to specify anything special. Then make your classpath point to the compiled generated classes, andcompile the custom code in this directory. Then you can use the SnmpDaemonTest class to start a JVM with theintsrumented MIB, and you can use e.g. the easymanager contrib ofJDMK to view the MIB through SNMP.  #==============================================================================#  Classes Details#============================================================================== Utility Classes developped for the JVM Management MIB:------------------------------------------------------JvmContextFactory.java        : The context factory allocates a Map that                                serves as request contextual cache.                                Values obtained from JSR 163 API can be                                cached in this object.                                A request contextual cache is allocated                                each time a request is being processed,                                and is released at the end of processing.				Object: 1) preserve atomicity                                        2) minimize API calls					3) ensure consistency of the					   various pieces of data returned. MibLogger.java                : Send traces to java.util.logging SnmpTableHandler.java         : an interface used to access table data. SnmpCachedData.java           : This object can be use to cache a snapshot                                of the data contained in a table.  SnmpTableCache.java           : A weak cache for table data. The data is                                computed on demand and cached in a                                 weakreference. Makes it possible to specify                                a validity period for the cache data. SnmpListTableCache.java       : Extends SnmpTableCache - for tables whose                                data is returned in a List object. SnmpNamedListTableCache.java  : Extends SnmpListTableCache - for tables whose                                elements can be named by a unique string. SnmpDaemonTest.java           : A dummy standalone SNMP agent that registers                                the JVM Managemnt MIB in Tiger's SNMP                                adaptor.  This is the "main". Note that                                this not the class that will be used to			        start the adaptor in the final Tiger - it is                                just a dummy test main. JVM Management MIB------------------ JVM_MANAGEMENT_MIB_IMPL.java  : subclasses the generated JVM_MANAGEMENT_MIB                                class. 				Object: overriding factory method in order                                        to instantiate custom code instead				        of generated code.  JVM Memory Group---------------- JvmMemoryImpl.java            : Provides instrumentation for the jvmMemory                                group. Replaces the generated JvmMemory class,                                which is not used and can be thrown away.                                Implements the generated JvmMemoryMBean                                 interface (which was also implemented by                                the generated JvmMemory skeleton class)                                Use  the request contextual cache				in order to ensure consistency when				returning MemoryUsage datas. Note that all                                tables in this group have been implemented                                as virtual tables. As a consequence, the                                generated TableJvmMemXXXXXTable.java classes                                are not needed. JvmMemoryMetaImpl.java        : Custom MetaData class for the jvmMemory group.			        Subclasses the generated JvmMemoryMeta class.                                Object: overrides the factory methods in order                                        to instantiate custom meta data classes                                        for the jvmMemManagerTable,						jvmMemGCTable,						jvmMemPoolTable,						jvmMemMgrPoolRelTable. JVM Memory Manager Table------------------------ JvmMemManagerTableMetaImpl.java : Custom MetaData class for the                                   jvmMemManagerTable. This MetaData traps				  all the SNMP Runtime calls made to the                                   table - in order to make the Memory Manager				  table virtual: i.e. the table does not have				  to be maintained permanently in memory.				  Instead, the table is computed "on demand",                                  and the data is cached in a weak cache                                  (see SnmpNamedListTableCache) which remains				  valid for a few ms. If the data is found				  to be obsolete, or was garbage collected,				  the table is recomputed. JvmMemManagerEntryImpl.java     : Custom Entry class for jvmMemManagerTable.				  Entries are created on the fly when it				  becomes necessary to get data from a 				  Memory Managers. They are temporary objects				  that wrap the MemoryManager just for the			          call duration - and are released just after.  JVM Memory GC Table------------------- JvmMemGCTableMetaImpl.java     : Custom MetaData class for the                                  jvmMemGCTable. This MetaData traps				 all the SNMP Runtime calls made to the                                  table - in order to make the GC				 table virtual: the GC table reuses the			         cached data computed for the                                  jvmMemManagerTable - simply acting as a                                  filter that only shows those elements that                                 are instance of GarbageCollectorMetrics.                                  In other words it implements a fitered view                                 of the jvmMemManagerTable. JvmMemGCEntryImpl.java         : Provide access to the data specific to				 GarbageCollectorMetrics objects. Objects				 of this classes are created on the fly,				 when data needs to be returned from a 				 GarbageCollectorMetrics object, and are                                 released just after. They are not kept in				 memory. JVM Memory Pool Table--------------------- JvmMemPoolTableMetaImpl.java   : Custom MetaData class for the jvmMemPoolTable.			         This is quite similar to what was done for                                 the jvmMemManagerTable in                                  JvmMemManagerTableMetaImpl. Most of the code                                 here was obtain by cut&paste-ing from                                 JvmMemManagerTableMetaImpl and replacing                                 "Manager" with "Pool". JvmMemPoolEntryImpl.java       : Provide access to the data specific to				 MemoryPoolMetrics objects. Objects				 of this classes are created on the fly,				 when data needs to be returned from a 				 MemoryPoolMetrics object, and are                                 released just after. They are not kept in				 memory. Use  the request contextual cache				 in order to ensure consistency when				 returning MemoryUsage datas.  JVM Memory Manager / Memory Pool Relation  Table------------------------------------------------  JvmMemMgrPoolRelTableMetaImpl.java : Custom MetaData class for the                                  jvmMemMgrPoolRelTable. This meta data			         uses the JvmMemManagerTableMetaImpl and                                 JvmMemPoolTableMetaImpl in order to                                  find out the content of the 			         jvmMemManagerTable and the mapping between 				 Memory Pool Name and Memory Pool Index.				 For each element of the jvmMemManagerTable                                 it calls the JSR 163 APIs to find the				 related Memory Pool, then finds out their				 index, and then creates the corresponding				 row in the jvmMemMgrPoolRelTable cached data.				 Like all the other tables, this table is				 virtual: the data is kept on a weak cache				 and recomputed on demand, if its validity				 as expired or if it has been gc'ed. JvmMemMgrPoolRelEntryImpl.java : A simple couple MemoryManager/MemoryPool.                                 Models a row in the jvmMemMgrPoolRelTable.				 Objects of this type are cached in the				 jvmMemMgrPoolRelTable cached data. #==============================================================================#==============================================================================