Scheduled restart of Service Manager processes

The restart command allows administrators to schedule the restart of one or all Service Manager processes on a host. Restarting one or more processes allows Service Manager to offer high availability without having to restart the entire Service Manager cluster. Typically, administrators want to restart Service Manager processes for one of the following reasons:

• The Service Manager system is running low on system resources while at normal load
• A particular Service Manager processes is consuming a large amount of system resources
• The administrator has some need to regularly restart Service Manager processes

These symptoms may arise from various causes such as faulty tailoring changes or unstable third-party libraries that increase memory consumption on your system. Restarting one or all Service Manager processes allows you to temporarily workaround any performance issues while you diagnosis the root cause and determine a permanent fix.

The restart command has two basic modes of operation:

• Restart a particular process
• Restart all processes on a host

Restart a particular process

If you can identify the processes comsuming system resources, you can restart them individually by process ID with the pid parameter. A process restart uses the following workflow:

1. The restart command notifies the process of a restart request
2. The process operates normally during the restart waiting period
3. The process goes into quiesce mode during the restart grace interval
4. The process restarts

You can schedule when a Service Manager process restarts with the value of the restart command. The value of the restart command determines the minimum amount of minutes a process waits before restarting. By default, there is no restart waiting period value so a process enters restart immediately.

During the restart waiting period, an administrator can cancel the restart by reissuing the restart command with a value of -1. You can specify the same process ID you originally listed with the pid parameter to cancel a process restart. You can only cancel a restart command during the restart waiting period. After a process is in the grace interval, you can no longer cancel a restart command.

After the restart waiting period has expired, the server checks to see if there is a restartGraceInterval value. This parameter determines how long the process will be quiesced and not accept any new connections (not even administrator accounts). This allows users currently connected to the process to complete their work and log off prior to the restart. Service Manager displays the following message to users during the grace interval:

Your Service Manager session is shutting down in %d minutes for maintenance. Please save your work and log out. You can log in again immediately.

Service Manager replaces the variable %d with the restartGraceInterval value. You can edit or localize the restart message from the notification engine.

By default, there is no restartGraceInterval value so all processes immediately restart. If you provide a restartGraceInterval, the process will remain quiesced for a number of minutes up to the value supplied or until all users log off, whichever comes first. If either condition is met the process restarts.

Note: Processes dedicated to Web Services connections or background schedulers ignore the restartGraceInterval value because they are stateless connections that do not require a user to log off. These processes restart immediately after the restart waiting period expires. After restart, the server will only run the background scheduler processes listed in the sm.cfg file or started from the OS command prompt. Background schedulers started from the System Status form are not automatically resumed.

Restart all processes on a host

If you cannot identify particular Service Manager processes that are consuming system resources, you can restart all Service Manager processes on a host with the host parameter.

Note: A host restart command does not restart the load balancer process. The only way to restart a load balancer process is to specify it by process ID.

A host restart uses the following workflow:

1. The restart command notifies all processes on the host of the restart request
2. The restart command randomly assigns a time extenstion to the restart time of each process
3. The processes operates normally during the restart waiting period
4. The processes go into quiesce mode during the restart grace interval
5. The process restarts

When Service Manager processes receive a restart command they first calculate a future restart time based on the values provided with the restart command and the restartRandMax sm.ini parameter. The value of the restart command determines the minimum amount of time a process waits before restarting. By default, there is no restart waiting period value so the server randomly assigns a time extension. The value of the restartRandMax parameter extends the restart waiting period by a random amount of minutes from 0 to the value provided in the command.

The purpose of the random restart time extension is to minimize the chance that two or more processes restart at the same time since each process that restarts briefly reduces system capacity. If you are only restarting one process, there is no need to stagger restart times to preserve capacity and therefore the server ignores any restartRandMax value.

During the restart waiting period, an administrator can cancel the restart by reissuing the restart command with a value of -1. You can only cancel a restart command during the restart waiting period. After a process is in the grace interval, you can no longer cancel a restart command.

After the restart waiting period has expired, the server checks to see if there is a restartGraceInterval value. This parameter determines how long the process will be quiesced and not accept any new connections (not even administrator accounts). This allows users currently connected to the process to complete their work and log off prior to the restart. Service Manager displays the following message to users during the grace interval:

Your Service Manager session is shutting down in %d minutes for maintenance. Please save your work and log out. You can log in again immediately.

Service Manager replaces the variable %d with the restartGraceInterval value. You can edit or localize the restart message from the notification engine. It is IDS_ALERT_RESTART message 126.

By default, there is no restartGraceInterval value so all processes immediately restart. If you provide a restartGraceInterval, the process will remain quiesced for a number of minutes up to the value supplied or until all users log off, whichever comes first. If either condition is met the process restarts.

Note: Processes dedicated to Web Services connections, background schedulers, or the load balancer process ignore the restartGraceInterval value because they are stateless connections that do not require a user to log off. These processes restart immediately after the restart waiting period expires. After restart, the server will only run the background scheduler processes listed in the sm.cfg file or started from the OS command prompt. Background schedulers started from the System Status form are not automatically resumed.

Recommendations

While a process is quiesced, the system loses some connection capacity because there are fewer processes to accept connection requests. Restarting one Service Manager process typically takes a short amount of time, approximately 30 seconds depending upon the system. In general, quiescing processes reduces capacity for longer than restarting them (several minutes quiesce time compared to 30 seconds restart time). For this reason, HPE recommends you set a high restartRandMax value to minimize the chance of two processes restarting at the same time, and a low restartGraceInterval value to minimize the amount of time your system has reduced capacity from quiesced processes.

If you want to regularly schedule the restart of one or all of your Service Manager processes, you must use your operating system's scheduling tools to run the restart command.