Analysis Date | JDK | Operating System | CPU Architecture | Debug JVM? |
---|---|---|---|---|
2021-05-04 | OpenJDK8 | Linux | x86 | N |
Results
Switches Identified
Switch Analysis
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
loggc | <file> | log GC status to a file with time stamps | ::/app/cassandra/logs/gc.log-ea | |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
UseThreadPriorities | boolean | Use native thread priorities | true | |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
ThreadPriorityPolicy | int | 0 : Normal. VM chooses priorities that are appropriate for normal applications. On Solaris NORM_PRIORITY and above are mapped to normal native priority. Java priorities below NORM_PRIORITY map to lower native priority values. On Windows applications are allowed to use higher native priorities. However, with ThreadPriorityPolicy=0, VM will not use the highest possible native priority, THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with system threads. On Linux thread priorities are ignored because the OS does not support static priority in SCHED_OTHER scheduling class which is the only choice for non-root, non-realtime applications. 1 : Aggressive. Java thread priorities map over to the entire range of native thread priorities. Higher Java thread priorities map to higher native thread priorities. This policy should be used with care, as sometimes it can cause performance degradation in the application and/or the entire system. On Linux this policy requires root privilege. |
0 | 42 |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
HeapDumpOnOutOfMemoryError-Xss256k | true | |||
Analysis | Switch not found in any JDK. Did you mean 'HeapDumpOnOutOfMemoryError' ? |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
StringTableSize | int | Number of buckets in the interned String table | defaultStringTableSize | 1000003 |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
AlwaysPreTouch | boolean | Force all freshly committed pages to be pre-touched | false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
UseBiasedLocking | boolean | Enable biased locking in JVM | true | false |
Analysis | This switch will be removed in the future. It will be Deprecated in OpenJDK15. Obsoleted in OpenJDK18. Expired in OpenJDK19. |
Name | Type | Description | Default Value | Your Value | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
UseTLAB | boolean | Use thread-local object allocation |
|
true | |||||||||
Analysis | OK |
Name | Type | Description | Default Value | Your Value | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ResizeTLAB | boolean | Dynamically resize TLAB size for threads |
|
true | |||||||||
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
+PerfDisableSharedMem-Djava.net.preferIPv4Stack | true | |||
Analysis | Switch not found in any JDK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
UseParNewGC | boolean | Use parallel threads in the new generation | false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
UseConcMarkSweepGC | boolean | Use Concurrent Mark-Sweep GC in the old generation | false | true |
Analysis | This switch will be removed in the future. It will be Obsoleted in OpenJDK14. Expired in OpenJDK15. |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
CMSParallelRemarkEnabled | boolean | Whether parallel remark enabled (only if ParNewGC) | true | true |
Analysis | This switch will be removed in the future. It will be Obsoleted in OpenJDK14. Expired in OpenJDK15. |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
SurvivorRatio | int | Ratio of eden/survivor space size | 8 | 8 |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
MaxTenuringThreshold | int | Maximum value for tenuring threshold | 15 | 1 |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
CMSInitiatingOccupancyFraction | int | Percentage CMS generation occupancy to start a CMS collection cycle. A negative value means that CMSTriggerRatio is used |
-1 | 75 |
Analysis | This switch will be removed in the future. It will be Obsoleted in OpenJDK14. Expired in OpenJDK15. |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
UseCMSInitiatingOccupancyOnly | boolean | Only use occupancy as a criterion for starting a CMS collection | false | true |
Analysis | This switch will be removed in the future. It will be Obsoleted in OpenJDK14. Expired in OpenJDK15. |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
CMSWaitDuration | int | Time in milliseconds that CMS thread waits for young GC | 2000 | 10000 |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
CMSParallelInitialMarkEnabled | boolean | Use the parallel initial mark. | true | true |
Analysis | This switch will be removed in the future. It will be Obsoleted in OpenJDK14. Expired in OpenJDK15. |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
CMSEdenChunksRecordAlways | boolean | Always record eden chunks used for the parallel initial mark or remark of eden |
true | true |
Analysis | This switch will be removed in the future. It will be Obsoleted in OpenJDK14. Expired in OpenJDK15. |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
CMSClassUnloadingEnabled | boolean | Whether class unloading enabled when using CMS GC | true | true |
Analysis | This switch will be removed in the future. It will be Obsoleted in OpenJDK14. Expired in OpenJDK15. |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
PrintGCDetails | boolean | Print more details at garbage collection | false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
PrintGCDateStamps | boolean | Print date stamps at garbage collection | false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
PrintHeapAtGC | boolean | Print heap layout before and after each GC | false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
PrintTenuringDistribution | boolean | Print tenuring age information | false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
PrintGCApplicationStoppedTime | boolean | Print the time the application has been stopped | false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
PrintPromotionFailure | boolean | Print additional diagnostic information following promotion failure |
false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
UseGCLogFileRotation | boolean | Rotate gclog files (for long running applications). It requires -Xloggc:<filename> |
false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
NumberOfGCLogFiles | int | Number of gclog files in rotation (default: 0, no rotation) |
0 | 10 |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
GCLogFileSize | int | GC log file size, requires UseGCLogFileRotation. Set to 0 to only trigger rotation via jcmd |
8*K | 10M-Xms3970M-Xmx3970M-Xmn400M |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
UseCondCardMark | boolean | Check for already marked card before updating card table | false | true |
Analysis | OK |
Name | Type | Description | Default Value | Your Value |
---|---|---|---|---|
CompileCommandFile | string | Read compiler commands from this file [.hotspot_compiler] | NULL | /etc/cassandra/hotspot_compiler-javaagent |
Analysis | OK |