RTmon, a Visual IPC Tool

The GDI portion of RTmon has been deprecated and may be removed in a future release.

RTmon is a very powerful tool that you can use to monitor and control your entire distributed application through a graphical interface, called the RTmon GDI or through a command-mode interface, called the RTmon Command Interface (CI). The RTmon GDI provides a point-and-click tool for monitoring your application in real time, allowing you to watch critical IPC information such as the number of messages a process has in its message queue. The RTmon Main window presents an animated graphical tree of a project, with nodes in the tree representing RTclients, the subjects to which they are subscribed, and the RTservers running. As changes occur, such as a process leaves the project, the Project Tree is updated in real time. The RTmon GDI even allows you to look at individual messages and their contents as they are passed from program to program.

One of the principal features of RTmon is that it is non-intrusive. It allows you to monitor, debug, and log information in a project without changing the running processes. RTmon also provides real-time system usage information on processes, such as CPU and memory resources. This is useful for stopping a process that is using excessive system resources (with a CONTROL message whose data part consists of the string "quit force").

You can even build a message in RTmon GDI, using only the point-and-click interface, and send it to one or more processes in the project.

The best way to learn how to use RTmon is to get it up and running.

You need a project to monitor first, so start the send2 and receive programs each in separate windows.

Step 27

Start the receiving program

First start the receiving program:

$ receive.x 

$ run receive 

$ receive 

Step 28

Start the sending program

Then, after a few moments, start the sending program:

$ send2.x 

$ run send2 

$ send2 

Step 29

Copy the rtmon.cm file

Copy the file rtmon.cm into your working directory. The rtmon.cm file stores commands executed by the rtmon program during initialization.

Step 30

Start the RTmon GDI

Start the RTmon GDI running in your third window using the rtmon command, which is the same for all three platforms presented in this tutorial:

$ rtmon 

It takes a moment for RTmon to initialize.

Step 31

Go to the Project Browser window

You are presented with an Information dialog box telling you that you did not set the Project. Click OK. The Project Browser window appears.

Step 32

Create an rtmon.com startup command file

To prevent this Information dialog box from coming up in the future, create an rtmon.cm startup command file (text) with the Project option set as shown:

setopt project smartsockets 

The Project Browser window presents a list of available projects (once you set your rtmon.cm file, smartsockets is listed as one of the projects.)

Step 33

Change the selected project

Click smartsockets, then click Change Project. When the Confirmation dialog comes up to disconnect from the RTserver, click OK. To close the Project Browser window, click Close.

You are now monitoring the project in real time.

The Main RTmon window is shown in Figure 8.

The content and function of the RTmon GDI are identical between the Windows and Motif platforms.

Notice the graphical tree of the project. From left to right, it shows the name of the project, then all the RTservers running in the project, followed by the RTclients, and at the far-right the subjects to which each of the RTclients are subscribing are displayed.

The Project Tree should be showing three RTclients: sender, receiver, and RTmon. Note that RTmon is just another RTclient, and, in fact, you can even use RTmon to monitor other RTmons, including itself.

This Project Tree is animated. As changes occur in the project, the tree is updated in real time. For example, if a process unsubscribes from a subject, you would see that subject disappear from the tree. This tree is an excellent way of getting a visual picture of your complete project.

All the items in the Project Tree are selectable. Double click on any item in the tree and a window appears from which you can poll or watch more information.

Let’s make a change in the tree by sending a CONTROL message to the sending program (specified in the tree by its unique subject, /lesson5/sender) to "quit force", which stops the process.

Step 34

Go to the Send Message window

In the middle of the Main window, right below the Project Tree, there are a series of buttons. Click Send.... This brings up the Send Message window, shown in Figure 9. (Figure 9 shows the Motif Send Message window but the Windows version has the same functions.)

To build the message, first set the subject to where the message is going to be sent.

Step 35

Select a subject

Click Select.... In the Subject Selection box, click /lesson5/sender and click OK (or simply type /lesson5/sender in the Publish to Subject field located to the right of the Select button).

Now the destination subject is set. You are sending the message to the /lesson5/sender subject.

Step 36

Select the message type to send

In the Select Message Type scroll box, select the control message type. In the bottom part of this window, a text entry box for Field: 1 appears. Enter this string:

quit force 

The Send Message window should look similar to the window displayed in Figure 9.

Step 37

Send the message

Now click Send to send the message to the remote process to terminate it.

An Information box appears, notifying you that the message was sent successfully.

Step 38

Click OK

Upon receipt of the CONTROL message, send2 stops and the Project Tree in the Main window is updated in real time to reflect the fact that the process is no longer running.

Step 39

Start the sending program again

In a separate window, start the sending program again:

$ send2.x 

$ run send2 

$ send2 

Notice how the Project Tree is again updated when the process joins the project.

Step 40

Stop all running processes

To clean up and stop all the running processes, including RTmon, construct another CONTROL message, sending this message to the _all subject that all processes automatically subscribed to. In the Field box, enter quit force again. Click Send to stop all the processes.

RTmon disappears from your screen when it receives the CONTROL message.