7.10.1 Checking whether the application is effective
The functionality for controlling object movement to Explicit memory blocks prevents objects from moving to the Explicit heap when Full GC occurs. You can determine whether application of this functionality is effective by checking Explicit memory block information included in the thread dump and event log of the Explicit Memory Management functionality. If the usage of Tenured area is less and Explicit memory blocks satisfying the following conditions are present, application of the functionality is effective. Therefore, review the use of the functionality.
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EM_NAME in Explicit memory block information is null (it is an Explicit memory block for which automatic release processing is executed once).
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If you compare the value of EH_TOTAL in Explicit memory block information with another Explicit memory block, it is an extremely large Explicit memory block.
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In the log data that was output to the event log for the Explicit Memory Management functionality when Full GC occurred, the <EH_USED_AF> value is much greater than the <EH_USED_BF> value.
The functionality for specifying classes to be excluded from the application of the Explicit Memory Management functionality is a functionality to specify the object, which is the cause, and not allow it to move to the Explicit heap when the processing of automatic release of Explicit memory blocks take times even by using the functionality for controlling object movement. If you apply the functionality for specifying classes to be excluded from the application of the Explicit Memory Management functionality, objects of the classes specified in the configuration file are excluded from application. You can determine whether application of this functionality is effective by checking Explicit memory block information included in the thread dump. If the usage of Tenured area is less and the Explicit memory block includes classes satisfying the following conditions, it means application of the functionality is effective and hence review the use of the functionality.
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EM_NAME in Explicit memory block information is NULL (it is an Explicit memory block for which automatic release processing is executed once).
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If you compare the value of EH_TOTAL in Explicit memory block information with other Explicit memory block, it is an extremely large Explicit memory block.
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Objects having large value of ISIZE in object statistics and low value of FRATIO in object release rate information in Explicit memory block information exist and its class is other than the classes provided by Java SE.
For details on the output contents of Explicit memory block information included in the thread dump, see 5.5 JavaVM Thread Dump in the uCosminexus Application Server Maintenance and Migration Guide. For details on the event log of the Explicit Memory Management functionality, see 5.11 Event log of Explicit Memory Management functionality in the uCosminexus Application Server Maintenance and Migration Guide.