3.3.5 CTM domains and CTM domain managers

A CTM domain is a range of area in which CTM daemons exchange information about registered business-processing programs and schedule queue load status with each other to share information and perform load balancing. Each CTM domain is identified by a CTM domain name. Requests are distributed and scheduled among the CTM daemons in the same CTM domain. The range of each CTM domain and the information about the CTM daemons in each CTM domain are managed by the CTM domain manager.

Tip: CTM domains are included in the management domain managed by Management Server.

Important note: Adding CTM domains increases information in the file system. For CTM domains that are no longer used, use the ctmdminfo command to delete the CTM domain information.

A CTM domain manager is a daemon process that manages the information about the CTM daemons that exist in the same CTM domain. A CTM domain manager is required on each host on which CTM daemons are deployed.

The way a CTM domain manager distributes information to other CTM domain managers differs depending on whether the other CTM domain managers are in other network segments.

Note that the functionality of CTM domain managers is configured by specifying arguments for the ctmdmstart command executed at startup of CTM daemon managers. In a system set up by using the management portal, configuration can be completed by using logical CTM beforehand. For details about the command, see ctmdmstart (start CTM domain manager) in the uCosminexus Application Server Command Reference Guide.

Important note

To start a CTM domain manager as a Windows service, specify -Dvbroker.orb.isNTService=true as a startup command option.
If a CTM daemon terminates abnormally in Windows, the CTM domain manager forcibly terminates the child processes of the CTM daemon.
If a CTM domain manager terminates abnormally, execute the CTM domain manager normal startup command (ctmdmstart) with the -CTMForceStart or -CTMAutoForce option.

Organization of this subsection

(1) Sharing information with CTM domain managers in the same network segment
(2) Sharing information with CTM domain managers in different network segments
(3) Restarting only the CTM domain manager
(4) Checking the operating status of CTM domain managers

(1) Sharing information with CTM domain managers in the same network segment

A CTM domain manager distributes information about the CTM daemons that exist on the host to the CTM domain managers on other hosts by broadcast. The following figure shows how CTM domain managers in the same network segment share information.

Figure 3‒10: Sharing information with CTM domain managers in the same network segment

To add a new CTM daemon to an existing CTM domain, on a host in that CTM domain, start a CTM domain manager that has the same domain name and port number as other CTM domain managers. A new CTM daemon will then participate in the domain. You do not need to update the environment definitions and other information in the existing CTM domain. Therefore, you can easily scale out the system by simply copying the system environment.

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(2) Sharing information with CTM domain managers in different network segments

Broadcast cannot send information beyond routers, and, therefore, cannot be used to share information between CTM domain managers in different network segments. For these CTM domain managers to share information, the information must be distributed by using Smart Agent.

The following figure shows how CTM domain managers in different network segments share information.

Figure 3‒11: Sharing information with CTM domain managers in different network segments

The following shows the settings that are necessary to create a CTM domain with multiple network segments:

When starting a CTM domain manager, specify the host name or IP address of the CTM domain manager that information is to be shared with.

You can specify the queue in which requests can be registered by using the -CTMSendHost argument of the ctmdmstart command at startup of CTM domain managers. In a system set up by using the management portal, the queue can be set beforehand by using logical CTM.
Connect the Smart Agent in the local network segment to the Smart Agent in the other network segment.

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(3) Restarting only the CTM domain manager

If a CTM domain manager terminates abnormally, you might be able to restart only the CTM domain manager when restart is attempted. Whether restart is possible is automatically determined. If impossible, the entire system terminates abnormally, and you must restart the entire system.

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(4) Checking the operating status of CTM domain managers

A CTM domain manager checks whether the CTM domain managers on other hosts are running. The interval time at which a CTM domain manager performs this check can be changed. To change the check interval time, use the -CTMAliveCheckCount option of the ctmdmstart command.

If a CTM domain manager performs an operating status check and does not receive CTM node information, it judges that the CTM domain managers on those nodes are not running. The CTM domain manager then deletes the CTM information about those nodes. No requests will be distributed to the CTM daemons on those nodes. The following figure shows how a CTM domain manager checks the operating status of other CTM domain managers.

Figure 3‒12: Checking the operating status of CTM domain managers

The host-B CTM domain manager waits for the information about the host-A CTM daemon from the host-A CTM domain manager. The host-B CTM domain manager waits for response for the following time: CTM daemon information transmission interval × dead-or-alive decision monitoring coefficient. If the wait times out, the host-B CTM domain manager deletes the information about the host-A CTM daemon, and notifies the host-B CTM daemon that the information about the host-A CTM daemon was deleted. As a result, the host-B CTM daemon will not distribute any requests to the host-A CTM daemon.

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