1.3 ZENworks Probe

ZENworks Probe is an open source diagnostics toolkit useful in monitoring Java applications. The ZENworks Probe page has the following tabs:

1.3.1 Applications

The Application tab, provides information about each Web application deployed on the Tomcat server: list of Web application with total number of requests processed, whether it is running, total number of sessions, session timeout, and whether it is distributable.

The following tasks can be performed from this tab:

Icons / Link	Task
	Click this icon to undeploy the application.
Status	Click this link to stop or start an application.
	Click this icon to refresh the application status.
Request count	Click this link to open the Servlet page. This page provides information about the number of request per servlet.
	Click this icon to get statistics for all of the Web applications.

This tab lists the installed web applications for the Tomcat server. The NAME, STATUS, DESCRIPTION, REQ, SESS TIMEOUT, CLSTRED.?, and SESS. fields are displayed in the panel.

NAME: Specifies the application name. Click the application name to open the Application Summary page.

STATUS: Specifies the status of the application, running or down. Click the status to stop or start an application.

REQ: Specifies the number of requests for the application. Click REQ to sort the application by request count. This helps you see how loaded an application is.

CLSTRED.?: Specifies whether the application is distributable.

SESS.: Specifies the session count.

This page provides the following information:

Application Summary

This page gives you the information that is specific to the selected application: Doc.Base, Servlet version, Number of servlets present for that application, session timeout, and whether it is serial or not.

The graphical representation of NUMBER OF REQUESTS and AVERAGE RESPONSE TIME helps users to determine the load for that application at any given time.

The following tasks can be performed by clicking on the icons:

Icon	Description
	Click this icon to stop the application.
	Click this icon to reload the application.
	Click this icon to undeploy the application. NOTE:If an application is undeployed, it cannot be deployed through probe again. However, it can be deployed by copying the webapp from another server or by locating the package that provides the webapp, extracting the .war file, and then deploying it.

Application Information

The Application Information panel displays the Application name, Doc.base, Description, Servlet version, Servlet count, Session timeout, and Clustered application information.

Doc.base: The document base directory (known as Context Root) for this web application, or the path name to the web application archive file (if executed directly from the WAR file).

Servlet count: The number of servlets available for this application. Click the servlet count value to open the Servlets page.

Statistics Charts

This panel displays the following statistics charts for the application:

NUMBER OF REQUESTS: A chart with coordinates corresponding to the REQUEST COUNT (Total number of requests for that application) and ERROR COUNT (Number of errors).

AVERAGE RESPONSE TIME (MS): A chart with coordinates corresponding to PROCESSING TIME (Processing time for the request), MIN TIME (Minimum time), MAX TIME (Maximum time), and AVG RESPONSE TIME (Average response time).

Application Deployment Descriptor

This page displays the web.xml of the application. This contains important information such as url-mapping, which helps you understand which servlet will be called for a specific type of URL.

Click download to download the XML file.

Application Servlet

The Application Servlet page displays the NAME, AVAIL, STARTUP, LOAD TIME, REQ., PROC TIME, ERR, MIN TIME, MAX TIME, MULTI THRD, Servlet mappings and Show All servlet information.

AVAIL: Whether the servlet is available.

STARTUP: The sequence in which the servlet is loaded at servlet container startup.

REQ.: The number of requests processed by each servlet.

PROC TIME: The time taken by the servlet to process all the request received.

ERR: The error count.

MIN TIME: The minimum time taken to process the request.

MAX TIME: The maximum time taken to process the request.

MULTI THRD: Whether the servlet is multithreaded.

Servlet mappings: Opens the Servlet mapping page.

Show All: Opens the Servlet page, which lists the information for all servlets on the Tomcat server.

Servlet Mappings

The Servlet Mapping page displays URL, SERVLET NAME, SERVLET CLASS, and AVAIL mapping between the servlets and the URLs.

AVAIL: Whether the servlet is available.

1.3.2 Threads

The Threads tab displays the ID, NAME, EXEX. POINT, STATE, IN.NATIVE, SUSP., WC, BC, Thread Pool, and Dump All Threads information about the threads running on the current Java Virtual Machine (JVM).

EXEX. POINT: The current execution point for the thread.

IN.NATIVE: Whether the thread is executing native code.

SUSP.: Whether the thread is suspended.

WC: The total number of times the thread was in wait notification state.That is, the number of times a thread has been in java.lang.Thread.State.WAITING or java.lang.Thread.State.TIMED_WAITING state.

BC: The total number of times the thread was blocked. That is, the number of times a thread has been in the java.lang.Thread.State.BLOCKED state.

Threads Pool: Click this link to open the Threads Pools page.

Dump All Threads: Click this link to access the thread dump of the system in its present state. This can be saved on the local machine and opened in any thread dump analyzer.

Threads Pools

The Threads Pools page displays the NAME, CURRENT THREAD COUNT, CURRENT THREADS BUSY, MAX THREADS, MAX SPARE THREADS, and MIN SPARE THREADS thread pool information for the Tomcat process.

1.3.3 System

This page provides links to the following system information:

Overview: Open the System Information page.

Memory utilization: Open the Memory Utilization page.

System properties: Open the System Properties page.

OS information: Open the OS Information page.

System Overview

This page provides information about memory utilization, operating system, and the Tomcat container.

Memory Utilization Panel

This panel displays the CURRENT MEMORY USAGE IS, FREE, TOTAL, MAX and Advice GC and Dump Heap memory utilization information.

TOTAL: The total memory space.

MAX: The maximum memory space available.

Advice GC: Click this link to advise the JVM to perform garbage collection.

Dump Heap: Click this link to generate the memory dump of the JVM. This is stored in the machine where the target JVM is running.

OS Information Panel

This panel displays the JVM, OS, PROCESSORS, CURRENT TIME, and WORKING DIR OS information.

JVM: The Java platform and version.

OS: The operating system name and version.

PROCESSORS: The number of processors.

WORKING DIR: The working directory for the Tomcat server.

Container information Panel

This panel displays the CONTAINER, CATALINA.BASE, CATALINA.HOME, APPLICATION BASE, and CONFIGURATION BASE Tomcat container information.

Memory Utilization

This page displays the memory utilization for Java objects in different generations and based on the usage, can even advise for garbage collection. This page has the following panels:

CURRENT MEMORY USAGE:

NAME: The name of the pool.
USAGE SCORE: The usage scope bar chart.
PLOT: Hides or unhides the memory usage graph.
USED: The amount of memory currently used, including the memory occupied by all objects, both reachable and unreachable.
COMMITTED: The amount of memory guaranteed to be available for use by the JVM. The amount of committed memory may change over time. For example, the Java virtual machine might release memory to the system, so the amount of committed memory could be less than the amount of memory initially allocated at start up. The amount of committed memory will always be greater than or equal to the amount of used memory.
MAXIMUM: The maximum amount of memory that can be used for memory management. Its value could change or be undefined. A memory allocation could fail if the Java VM attempts to increase the used memory to an amount greater than committed memory, even if the amount used is less than or equal to maximum value (for example, when the system is low on virtual memory).
INITIAL: The initial memory allocated.
TOTAL: The total memory allocated.

MEMORY USAGE HISTORY:

Permanent Generation (non-heap): The pool containing all of the reflective data on the virtual machine itself, such as class and method objects. With Java VMs that use class data sharing, this generation is divided into read-only and read-write areas.
Tenured Generation (heap): The pool containing objects that have existed for some time in the survivor space.
Survivor Space (heap): The pool containing objects that have survived the garbage collection of the Eden space.
Code Cache (non-heap): The HotSpot JVM also includes a code cache, containing memory that is used for the compilation and storage of native code.
Eden Space (heap): The pool from which memory is initially allocated for most objects.

System Properties

This page displays the following Java system properties information:

PROPERTY NAME: The system property name.

PROPERTY VALUE: The property value.

OS Information

This page displays the following operating system information:

OS Information: This panel displays the OS name, Version, Total RAM, Free RAM, Committed JVM memory (the amount of virtual memory guaranteed to be available to the running process), Total swap, and Free swap.

HISTORICAL CHARTS: This panel displays the JVM CPU UTILIZATION (%) chart, OS & JVM MEMORY USAGE(KB) chart, and SWAP USAGE(KB) chart.

1.3.4 Connectors

This page provides the list of connectors and its information for Tomcat servers. The charts in this tab helps users to find out the number of incoming requests for each connector and how much time it took to process at each interval and the amount of data that got transferred at each interval. The user can find the remote IP which is requesting for a particular URL and the time it took for processing that request.

The following chart is displayed for each connector type:

NUMBER OF REQUESTS IN EACH INTERVAL: The number of requests in each interval.

PROCESSING TIME (MS) IN EACH INTERVAL: The processing time spent for the requests in each interval.

TRAFFIC VOLUME (BYTES) IN EACH INTERVAL: The traffic volume in each interval.

Other information: The remote IP of the request, the stage of the request, processing time for the request, and the originating URL of the request has come.