System status

Introduction

In the Operations tab of the administration area, there are 3 tools that let you check system status and performance:

• General, to view the general status of the system,
• Properties, to view the system properties for launching the virtual machine java,
• Monitoring, to view system status monitoring curves.

Click on one of the 3 buttons to view details.

General

The General tool lists global information about the server deploying the application:

The System section provides information on operating system, processor type and server date.

The Java section provides information on the installed version of Java and the start-up date.

The Ametys provides the path to the directory containing allAmetys internal data.

Memory usage shows the current memory status:

• Main: This is the memory used to store objects Java. In general, this is the memory we usually talk about. On Sun's JVM, this memory can be configured using the -Xmx and -Xms parameters.
• Internal: This is a lesser-known secondary memory used to load application code into the JVM. It is sometimes necessary to modify this value if you load a lot of applications into your servlet engine. This memory can be configured using the -server or -XX:[MaxPermSize] parameters.

For more details on JVM configuration, please refer to the JDK6/Virtual Machine documentation.

The "Recycle garbage can" icon to the right of the "Main memory" section allows you to force memory cleaning(garbage collecting). This feature can be used, for example, to highlight possible memory leaks.

The Server processing section details how the server is currently being used:

• Open sessions: Shows the number of users who have recently used the application. (Connection to the administration interface is also counted).
• Queries in progress: Displays the number of queries currently being processed (this total includes the query displaying this screen).
• Current threads: Displays the total number of threads in the JVM. This gives a good indication of the number of requests being processed simultaneously.

A label is displayed to alert you if a Thread isdeadlocked.

Remember that memory is shared between all applications deployed in the servlet engine.

Properties

The Properties tool lets you view the system properties for launching a virtual machine java :

Some interesting properties:

• java.io.tmpdir: Path to the temporary directory on the server.

• file.encoding: Character encoding used by default by Java.

   

Monitoring

The Monitoring tool lets you visualize the curves used to monitor system status. Select the graph you wish to study in the left-hand column:

The requested graph is displayed on the right-hand side of the screen:

You can hold down the mouse button and drag up, down, left or right. These actions change the time scale of each graph (from the last hour to the last year).

Annotate a chart

You can annotate a graph. To do so, activate the graph annotation by clicking on the Annotate graph button:

You can then draw on the graph using a stylus:

When chart annotation is activated, you can no longer set the chart zoom or scroll to the current position.

To deactivate the graph annotation, click the button again.

Download a chart

You can export a graphic in PNG format by clicking on the Download button:

Scroll to now

The Scroll to now button allows you to return to the curve you were navigating at time t :

Reload graphics

To update the graphics, click on the Reload graphics button :

Set chart zoom

In the Monitoring contextual menu, the Zoom levels buttons allow you to define the zoom of your graphs: