ManageEngine® Applications Manager


Chapter 6.19 Java Runtime Monitor

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Java Runtime Monitor

 

Java Runtime Monitor provides out-of-the-box remote monitoring and management on the Java platform and of applications that run on it. It gives memory and thread statistics. Thresholds can be associated and alarms generated.

 

Note: Support is available for JRE1.5 and above


The Availability tab gives the Availability history for the past 24 hours or 30 days. The Performance tab gives the Health Status and events for the past 24 hours or 30 days. The List view enables you to perform bulk admin configurations. Java Runtime Monitor checks the availability, response time, connection time (time taken by the Applications Manager to look up the JMX agent on the remote JVM) of the monitor, along with many other parameters listed below.


Parameter

Description

Monitor Information

Name

Name of the JavaRuntime monitor.

Health

Specifies the health (Clear, Warning, Critical) of the JavaRuntime monitor
Type Specifies the type you are monitoring.
Host Name Specifies the host at which the database server is running.
Port Specifies the port number at which the JavaRuntime monitor is running.

Host OS

Specifies the OS of the host where the JavaRuntime monitor is running.

Last Polled at

Specifies the time at which the last poll was performed.

Next Poll at

Specifies the time at which the next poll is scheduled.

Availability

Shows the current status of the JavaRuntime monitor - available or not available.

Connection Time

Time taken to connect to the JavaRuntime.

Process Memory

Eden Space (Heap Memory)

The pool from which memory is initially allocated for most objects.

Survivor Space (Heap Memory)

Pool containing objects that have survived GC of eden space.
Tenured Generation (Heap Memory) Pool containing objects that have existed for some time in the survivor space.
Permanent Generation (Non-Heap) Holds all the reflective data of the virtual machine itself, such as class and method objects. With JVMs that use class data sharing, this generation is divided into read-only and read-write areas.
Code Cache (Non-Heap) Memory used for compilation and storage of native code.
Thread Parameters  
Total threads started Total number of threads created and also started since the Java virtual machine started
Peak Threads Peak live thread count since the Java virtual machine started or peak was reset
Live Threads Number of live threads currently running
Daemon Threads Number of daemon threads currently running
Runnable Threads A thread executing in the Java virtual machine is in this state
Blocked Threads A thread that is blocked waiting for a monitor lock is in this state
Waiting Threads A thread that is waiting indefinitely for another thread to perform a particular action is in this state.
Timed waiting Threads A thread that is waiting for another thread to perform an action, for up to a specified waiting time is in this state
Deadlocked Number of threads that are in deadlock waiting to acquire object monitors
Virtual Memory Parameters  
Classes loaded Number of classes loaded
Classes Unloaded Number of classes unloaded
GC time Time taken to perform garbage collection
Compile time Time spent in just-in-time (JIT) compilation
Max file descriptor Maximum permissible open file descriptor. Available only for UNIX.
Host Memory Parameters
Total Physical Memory Total amount of physical memory in Megabytes
Free Physical Memory The amount of free physical memory in Megabytes
Total Swap Space Total amount of swap space in Megabytes
Committed Virtual Memory The amount of virtual memory that is guaranteed to be available to the running process in Megabytes
Garbage Collector
Time Spent/Min Approximate collection elapsed time in milliseconds.
Collections/Min Total number of collections that have occurred.
Thread Count Number of threads used for Garbage Collector
Last Start Time Start time of this GC
Last End Time End time of this GC
Memory usage before GC Memory usage of all memory pools at the beginning of this GC
Memory usage after GC Memory usage of all memory pools at the end of this GC
Configuration  
Uptime The uptime of the Java virtual machine
Java Virtual Machine The Java virtual machine implementation name
Vendor The Java virtual machine implementation vendor
Process ID The process identifier is a number used by some operating system kernels to uniquely identify a process
Name The name representing the running Java virtual machine
VM arguments The input arguments passed to the Java virtual machine which does not include the arguments to the main method
Class path The Java class path that is used by the system class loader to search for class files
Library path The Java library path
Boot class path The boot class path that is used by the bootstrap class loader to search for class files.
JIT compiler The name of the Just-in-time (JIT) compiler
Objects Pending for finalization The approximate number of objects for which finalization is pending.
Operating System The name of the operating system
Architecture The operating system architecture
Processors The number of processors available to the Java virtual machine

 

View Thread Dump

 

There is an option to view the thread dump history under 'Threads' tab. Click the 'View Thread Dump' link in the threads tab. The Thread Dump screen will open up in a new window and you will be able to view the current thread dump details. Once you close this window, the thread dump details will be moved under the Thread History section. You can view this information any time you want from this section.

 

Reports

 

We provide the option to view both realtime and historical data of any of the attributes present in the 'Configuration Information' section in the Configuration tab. Click on any attribute under the Configuration tab. This will open up a new window named 'History Data' that provides more information about these attributes.

 

There are two tabs in the History Data window - History Report and Global View

 

History Report: This tab provides historical reports of the attribute selected based on time period chosen. You can also use the Select Attribute drop-down box and view reports for other attributes.

 

Global View: This tab displays the current values of the attribute selected, across multiple monitors. To view information about other attributes present in the monitor, use the Select Attribute drop-down box and change the attribute.

 

If you want to view data of multiple attributes, click the Customize Columns link present at the top left corner of the window. This will take you to the Edit Global View screen. In this screen, you can change the monitor type using the Filter by Monitor Type drop-down box, select the metrics to be displayed, and show monitors on a monitor basis or a monitor group basis. After you select your options, click the Show Report button to view those information in the Global View tab.


Few Help Links for Reference:


Tuning Garbage Collection with the JVM
FAQ About the Java HotSpot VM
FAQ about Garbage Collection in the Hotspot JVM
Java Performance Documentation

 

See Also

Creating New Monitor - Java Runtime Monitor

 

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Script Monitor

Database Query Monitor