| #============================================================================== |
| # JVM Management MIB - Instrumentation Classes |
| #============================================================================== |
| |
| In this directory: |
| ------------------ |
| |
| README: this file |
| commands.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 for |
| tiger (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 that |
| the custom classes provided in this directory are all in the |
| sun.management.snmp.jvminstr package, and expect the generated classes to |
| be 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 (if |
| you read command.env you will see that I have put the custom classes |
| in a "custom" directory, and the generated classes in a "parsed" |
| directory. This makes it easier to cleanup the mib. You can safely |
| do a rm -rf <parsed> and call mibgen again. |
| |
| Then compile the generated classes - you will need JMX and Tiger SNMP |
| runtime classes in your classpath - if you compile with a tiger build that |
| already have them then you don't need to specify anything special. |
| |
| Then make your classpath point to the compiled generated classes, and |
| compile the custom code in this directory. |
| |
| Then you can use the SnmpDaemonTest class to start a JVM with the |
| intsrumented MIB, and you can use e.g. the easymanager contrib of |
| JDMK 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. |
| |
| #============================================================================== |
| #============================================================================== |
