Procmap and Cron

Procmap and the Auto–restarter

The process mapper, a.k.a. PROCMAP, is a program which stores state information on the processes which are currently running in the Auto–Nowcast Environment. The procmap window (shown below) displays the current process status.

Each line in the procmap window identifies a separate process in the Auto-Nowcast Environment.

• In the Name column is a list of the executables (or applications) which make up the Auto–Nowcast Environment.
• Instance is an additional descriptor which allows for unique identification of the executable processes. For example, the MDV_server appears multiple times in the process mapper, but the instance name distinguishes between each MDV_server by indicating on which dataset the server is operating.
• The Host column identifies the machine on which the process is running. It is useful to note that the procmap window orders processes alphabetically by host name first, then by executable name on each host.
• The User column indicates the login name under which a process is running. Since the Auto–Nowcast Environment is operated under the "nowcast" account, that username will appear for all of the processes.
• The Pid is the UNIX process identifier in the operating system's process table.
• Heartbeat indicates the length of time since the process last registered with procmap. Processes are configured to register once every minute.
• Uptime shows the length of time since the process was last restarted.

PROCMAP works together with the auto–restarter to keep processes up and running in the Auto–Nowcast Environment. The role of the auto–restarter is to make sure that all of the required processes are running and registering a regular heartbeat with the process mapper. Any process which is missing from the procmap or which has not registered a recent heartbeat is killed and restarted by the auto–restarter.

The auto–restarter makes a full check of the process list every minute. Any process which gets restarted is entered into a log file which is summarized nightly and mailed to the operator for daily maintenance checks.