Here is a brief list of suggested managed beans from the middleware applications that are part of your CLM system. In the reference section, we provide links to more detailed information.
Java Virtual Machine Managed Beans
The two key managed beans we consume from the Java Virtual Machine are the
Garbage Collector and
Operating System beans.
Garbage Collector
This managed bean is providing information about the Garbage Collector. It is used for monitoring the virtual machine's garbage collection metrics. The
CollectionTime,
CollectionCount should be used for alerts.
Key Attributes |
Description |
MBean |
Frequency |
LastCollectionEndTime |
Returns the end time in milliseconds of the last garbage collection that was carried out by this collector. |
GarbageCollector |
15m |
CollectionCount |
Returns the total number of collections that have occurred. This is set to -1 if the collection count is undefined for this collector. |
GarbageCollector |
15m |
CollectionTime |
Returns the approximate accumulated collection elapsed time in milliseconds. The Java virtual machine implementation may use a high resolution timer to measure the elapsed time. This method may return the same value even if the collection count has been incremented if the collection elapsed time is very short. |
GarbageCollector |
15m |
MemoryUsed |
Returns the amount of heap memory used by objects that are managed by the collector corresponding to this bean object. |
GarbageCollector |
15m |
TotalMemoryFreed |
Returns the cumulative total amount of memory freed, in bytes, by the garbage collector corresponding to this bean object. |
GarbageCollector |
15m |
TotalCompacts |
Returns the cumulative total number of compacts that was performed by garbage collector corresponding to this bean object. |
GarbageCollector |
15m |
LastCollectionStartTime |
Returns the start time in milliseconds of the last garbage collection that was carried out by this collector. |
GarbageCollector |
15m |
- Garbage Collector Object Name: java.lang:type=GarbageCollector, name=collector's name
Operating System
This managed bean is providing information about the operating system metrics. It is used for monitoring CPU, Swap Space and Physical Memory Usage. The
FreePhysicalMemorySize,
FreeSwapSpaceSize,
SystemCpuLoad should be used for alerts.
Key Attributes |
Description |
MBean |
Frequency |
SystemCpuLoad |
Returns the "recent cpu usage" for the whole system. This value is a double in the [0.0,1.0] interval. A value of 0.0 means all CPUs were idle in the recent period of time observed, while a value of 1.0 means that all CPUs were actively running 100% of the time during the recent period of time observed. All values between 0.0 and 1.0 are possible. |
OperatingSystem |
15m |
TotalPhysicalMemory |
Returns the total available physical memory on the system in bytes. |
OperatingSystem |
15m |
FreePhysicalMemorySize |
Returns the amount of physical memory that is available on the system in bytes. |
OperatingSystem |
15m |
TotalSwapSpaceSize |
Returns the total amount of swap space in bytes. |
OperatingSystem |
15m |
FreeSwapSpaceSize |
Returns the amount of free swap space in bytes. |
OperatingSystem |
15m |
- Operating System Object Name: java.lang:type=OperatingSystem
WebSphere Liberty Managed Beans
There are four managed beans we use from the WebSphere Liberty Application Server are
Liberty Java Virtual Machine,
Servlet Statistics,
Session Statistics and
Thread Pools beans.
Liberty Java Virtual Machine
This managed bean provides Liberty application server specific Java Virtual Machine information. It is available when the monitor-1.0 feature is enabled. It is used for monitoring the JVM information. Memory usage is a very important monitoring attribute for the Application Server. High memory usage could indicate high usage by deployed applications, heavy user workloads or memory leaks. The
UsedMemory and
ProcessCpu attributes should be used for alerts.
- Liberty Java Virtual Machine Object Name: WebSphere:type=JvmStats
Servlet Statistics
The Servlet Statistics managed bean is used to provide servlet response times. When the monitor-1.0 feature is enabled, one instance is available for each servlet that has been served, where * is of the form AppName.ServletName. It is used to monitor servlet counts and average response times. The
ResponseTime should be used for alerts.
- Liberty Servlet Statistics Object Name: WebSphere:type=ServletStats,name=*
Session Statistics
The session statistics managed bean is responsible for reporting SessionStats for a single web application. It is available when the monitor-1.0 feature is enabled.
Key Attributes |
Description |
MBean |
Frequency |
InvalidatedCountbyTimeout |
The total number of sessions invalidated by a timeout. |
SessionStats |
15m |
CreateCount |
Total number of sessions created. |
SessionStats |
15m |
LiveCount |
The total number of sessions that are currently cached in memory. |
SessionStats |
15m |
ActiveCount |
The total number of concurrently active sessions. A session is active if Liberty is processing a request that uses that session. |
SessionStats |
15m |
InvalidatedCount |
The total number of sessions that are invalidated. |
SessionStats |
15m |
- Liberty Session Statistics Object Name: WebSphere:type=SessionStats,Name=*
Thread Pools
The Thread Pool managed bean provides web container thread pool information. It is available when the monitor-1.0 feature is enabled. ThreadPoolStats is used to monitor the active threads usage in relation to the pool size. Liberty uses an auto-tuning algorithm to find the sweet spot for how many threads the server needs. Liberty is always playing around and adjusting the number of threads in the pool in-between and defined bounds for the coreThreads and maxThreads. In Liberty the threadpool size is autosized by
Liberty itself. The
ActiveThreads attribute should be used for alerts.
- Liberty Thread Pools Object Name: WebSphere:type=ThreadPoolStats,name=DefaultExecutor
Related topics:
External links:
Additional contributors: -- RichardWatts - 2018-03-20