1 #============================================================================== |
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2 # JVM Management MIB - Instrumentation Classes |
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3 #============================================================================== |
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4 |
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5 In this directory: |
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6 ------------------ |
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7 |
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8 README: this file |
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9 commands.env: a file containing some ksh variables & functions |
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10 that I have used to generate & compile all the |
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11 stuff. Probably only valid in my own environment. |
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12 logging.properties: logging.properties file that can be used to obtain |
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13 trace information. |
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14 *.java: utility and custom classes for the JVM Management MIB. |
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15 These classes show how to provide instrumentation for |
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16 a mibgen generated MIB, how to simulate virtual tables, |
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17 and how to make use of the SnmpUserDataFactory. |
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18 Only the jvmMemory group and its tables are instrumented. |
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19 |
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20 Dependency |
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21 ---------- |
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22 |
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23 jvmManagementMib.txt : the JVM Management MIB module in compilable form. |
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24 Tiger SNMP Runtime : SNMP Runtime classes for Tiger. We assume these |
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25 classes could be part of the JMX delivery |
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26 (classes in com.sun.jmx.snmp.*) |
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27 JDMK 5.1 : The jdmktk.jar contains the com.sun.jdmk.tools.MibGen class |
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28 used to compile the MIB. JDMK also has a mibgen.sh script |
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29 to start mibgen. By default mibgen generates code that can |
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30 integrate with JDMK SNMP runtime. In order to generate |
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31 code that integrate with Tiger SNMP runtime, you need to |
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32 start mibgen with a non-default resource file. |
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33 JDMK 5.1 workspace contains a mibgen resource file |
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34 specific for tiger: mibgen.property.tiger |
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35 Custom Instrumentation Code: the files in this directory. |
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36 |
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37 How to proceed: |
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38 --------------- |
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39 |
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40 Get mibgen from JDMK 5.1. Start mibgen with mibgen resource file for |
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41 tiger (add -Dcom.sun.jdmk.tools.mibgen.config.file=<mibgen.properties.tiger>) |
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42 on the Java command line. |
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43 |
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44 Use mibgen to generate code for the jvmManagementMib.txt file. Note that |
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45 the custom classes provided in this directory are all in the |
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46 sun.management.snmp.jvminstr package, and expect the generated classes to |
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47 be in another sun.management.snmp.jvmmib package (use mibgen option |
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48 -tp sun.management.snmp.jvmmib) |
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49 |
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50 If this package name does not suit you, simply change it to something else, |
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51 both in the custom classes below (you might use 'sed' or do it manually) |
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52 and in the -tp option that you will pass to mibgen. |
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53 |
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54 It is recommended to generate all classes in a different directory (if |
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55 you read command.env you will see that I have put the custom classes |
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56 in a "custom" directory, and the generated classes in a "parsed" |
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57 directory. This makes it easier to cleanup the mib. You can safely |
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58 do a rm -rf <parsed> and call mibgen again. |
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59 |
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60 Then compile the generated classes - you will need JMX and Tiger SNMP |
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61 runtime classes in your classpath - if you compile with a tiger build that |
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62 already have them then you don't need to specify anything special. |
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63 |
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64 Then make your classpath point to the compiled generated classes, and |
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65 compile the custom code in this directory. |
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66 |
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67 Then you can use the SnmpDaemonTest class to start a JVM with the |
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68 intsrumented MIB, and you can use e.g. the easymanager contrib of |
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69 JDMK to view the MIB through SNMP. |
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70 |
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71 #============================================================================== |
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72 # Classes Details |
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73 #============================================================================== |
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74 |
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75 Utility Classes developped for the JVM Management MIB: |
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76 ------------------------------------------------------ |
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77 JvmContextFactory.java : The context factory allocates a Map that |
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78 serves as request contextual cache. |
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79 Values obtained from JSR 163 API can be |
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80 cached in this object. |
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81 A request contextual cache is allocated |
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82 each time a request is being processed, |
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83 and is released at the end of processing. |
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84 Object: 1) preserve atomicity |
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85 2) minimize API calls |
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86 3) ensure consistency of the |
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87 various pieces of data returned. |
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88 |
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89 MibLogger.java : Send traces to java.util.logging |
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90 |
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91 SnmpTableHandler.java : an interface used to access table data. |
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92 |
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93 SnmpCachedData.java : This object can be use to cache a snapshot |
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94 of the data contained in a table. |
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95 |
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96 SnmpTableCache.java : A weak cache for table data. The data is |
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97 computed on demand and cached in a |
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98 weakreference. Makes it possible to specify |
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99 a validity period for the cache data. |
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100 |
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101 SnmpListTableCache.java : Extends SnmpTableCache - for tables whose |
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102 data is returned in a List object. |
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103 |
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104 SnmpNamedListTableCache.java : Extends SnmpListTableCache - for tables whose |
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105 elements can be named by a unique string. |
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106 |
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107 SnmpDaemonTest.java : A dummy standalone SNMP agent that registers |
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108 the JVM Managemnt MIB in Tiger's SNMP |
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109 adaptor. This is the "main". Note that |
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110 this not the class that will be used to |
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111 start the adaptor in the final Tiger - it is |
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112 just a dummy test main. |
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113 |
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114 JVM Management MIB |
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115 ------------------ |
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116 |
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117 JVM_MANAGEMENT_MIB_IMPL.java : subclasses the generated JVM_MANAGEMENT_MIB |
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118 class. |
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119 Object: overriding factory method in order |
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120 to instantiate custom code instead |
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121 of generated code. |
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122 |
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123 |
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124 JVM Memory Group |
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125 ---------------- |
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126 |
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127 JvmMemoryImpl.java : Provides instrumentation for the jvmMemory |
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128 group. Replaces the generated JvmMemory class, |
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129 which is not used and can be thrown away. |
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130 Implements the generated JvmMemoryMBean |
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131 interface (which was also implemented by |
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132 the generated JvmMemory skeleton class) |
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133 Use the request contextual cache |
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134 in order to ensure consistency when |
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135 returning MemoryUsage datas. Note that all |
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136 tables in this group have been implemented |
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137 as virtual tables. As a consequence, the |
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138 generated TableJvmMemXXXXXTable.java classes |
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139 are not needed. |
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140 |
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141 JvmMemoryMetaImpl.java : Custom MetaData class for the jvmMemory group. |
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142 Subclasses the generated JvmMemoryMeta class. |
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143 Object: overrides the factory methods in order |
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144 to instantiate custom meta data classes |
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145 for the jvmMemManagerTable, |
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146 jvmMemGCTable, |
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147 jvmMemPoolTable, |
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148 jvmMemMgrPoolRelTable. |
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149 |
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150 JVM Memory Manager Table |
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151 ------------------------ |
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152 |
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153 JvmMemManagerTableMetaImpl.java : Custom MetaData class for the |
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154 jvmMemManagerTable. This MetaData traps |
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155 all the SNMP Runtime calls made to the |
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156 table - in order to make the Memory Manager |
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157 table virtual: i.e. the table does not have |
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158 to be maintained permanently in memory. |
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159 Instead, the table is computed "on demand", |
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160 and the data is cached in a weak cache |
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161 (see SnmpNamedListTableCache) which remains |
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162 valid for a few ms. If the data is found |
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163 to be obsolete, or was garbage collected, |
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164 the table is recomputed. |
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165 |
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166 JvmMemManagerEntryImpl.java : Custom Entry class for jvmMemManagerTable. |
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167 Entries are created on the fly when it |
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168 becomes necessary to get data from a |
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169 Memory Managers. They are temporary objects |
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170 that wrap the MemoryManager just for the |
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171 call duration - and are released just after. |
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172 |
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173 JVM Memory GC Table |
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174 ------------------- |
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175 |
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176 JvmMemGCTableMetaImpl.java : Custom MetaData class for the |
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177 jvmMemGCTable. This MetaData traps |
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178 all the SNMP Runtime calls made to the |
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179 table - in order to make the GC |
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180 table virtual: the GC table reuses the |
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181 cached data computed for the |
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182 jvmMemManagerTable - simply acting as a |
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183 filter that only shows those elements that |
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184 are instance of GarbageCollectorMetrics. |
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185 In other words it implements a fitered view |
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186 of the jvmMemManagerTable. |
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187 |
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188 JvmMemGCEntryImpl.java : Provide access to the data specific to |
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189 GarbageCollectorMetrics objects. Objects |
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190 of this classes are created on the fly, |
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191 when data needs to be returned from a |
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192 GarbageCollectorMetrics object, and are |
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193 released just after. They are not kept in |
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194 memory. |
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195 |
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196 JVM Memory Pool Table |
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197 --------------------- |
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198 |
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199 JvmMemPoolTableMetaImpl.java : Custom MetaData class for the jvmMemPoolTable. |
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200 This is quite similar to what was done for |
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201 the jvmMemManagerTable in |
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202 JvmMemManagerTableMetaImpl. Most of the code |
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203 here was obtain by cut&paste-ing from |
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204 JvmMemManagerTableMetaImpl and replacing |
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205 "Manager" with "Pool". |
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206 |
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207 JvmMemPoolEntryImpl.java : Provide access to the data specific to |
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208 MemoryPoolMetrics objects. Objects |
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209 of this classes are created on the fly, |
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210 when data needs to be returned from a |
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211 MemoryPoolMetrics object, and are |
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212 released just after. They are not kept in |
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213 memory. Use the request contextual cache |
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214 in order to ensure consistency when |
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215 returning MemoryUsage datas. |
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216 |
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217 JVM Memory Manager / Memory Pool Relation Table |
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218 ------------------------------------------------ |
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219 |
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220 |
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221 JvmMemMgrPoolRelTableMetaImpl.java : Custom MetaData class for the |
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222 jvmMemMgrPoolRelTable. This meta data |
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223 uses the JvmMemManagerTableMetaImpl and |
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224 JvmMemPoolTableMetaImpl in order to |
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225 find out the content of the |
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226 jvmMemManagerTable and the mapping between |
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227 Memory Pool Name and Memory Pool Index. |
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228 For each element of the jvmMemManagerTable |
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229 it calls the JSR 163 APIs to find the |
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230 related Memory Pool, then finds out their |
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231 index, and then creates the corresponding |
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232 row in the jvmMemMgrPoolRelTable cached data. |
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233 Like all the other tables, this table is |
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234 virtual: the data is kept on a weak cache |
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235 and recomputed on demand, if its validity |
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236 as expired or if it has been gc'ed. |
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237 |
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238 JvmMemMgrPoolRelEntryImpl.java : A simple couple MemoryManager/MemoryPool. |
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239 Models a row in the jvmMemMgrPoolRelTable. |
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240 Objects of this type are cached in the |
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241 jvmMemMgrPoolRelTable cached data. |
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242 |
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243 #============================================================================== |
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244 #============================================================================== |
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