4. Configure a Process Controller

Storm administrators should install and configure a process controller to monitor and run Apache Storm under supervision. Storm is a fail-fast application, meaning that it is designed to fail under certain circumstances, such as a runtime exception or a break in network connectivity. Without a watchdog process, these events can quickly take down an entire Storm cluster in production. A watchdog process prevents this by monitoring for failed Storm processes and restarting them when necessary.

This section describes how to configure supervisord to manage the Storm processes, but administrators may use another process controller of their choice, such as monit or daemontools.

Add the following stanzas to the /etc/supervisord.conf to configure Supervisor to start and stop all of the Storm daemons:

...
[program:storm-nimbus] 
command=storm nimbus 
directory=/home/storm
autorestart=true
user=storm

[program:storm-supervisor] 
command=storm supervisor
directory=/home/storm
autorestart=true
user=storm

[program:storm-ui]
command=storm ui
directory=/home/storm
autorestart=true
user=storm

[program:storm-logviewer]
command=storm logviewer
autorestart=true
user=storm

[program:storm-drpc]
command=storm drpc
directory=/home/storm
autorestart=true
user=storm

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