starman - Man Page

  starman --listen :5001 --listen /tmp/starman.sock
  starman --workers 32 --port 8080

-l,  --listen

  --listen HOST:PORT --listen :PORT --listen UNIX_SOCKET
  --listen HOST:PORT:ssl

Specifies the TCP address, ports and UNIX domain sockets to bind to wait for requests. You can repeat as many times as you want and mix TCP and UNIX domain sockets.

For TCP sockets you can append :ssl after the port to specify that connections on that port should use SSL. Note that the SSL support is experimental and hasn't been widely tested.

Defaults to any IP address and port 5000.

--host

  --host 127.0.0.1

Specifies the address to bind.

This option is for a compatibility with plackup and you're recommended to use --listen instead.

--port

  --port 8080

Specifies the port to bind.

This option is for a compatibility with plackup and you're recommended to use --listen instead.

-S,  --socket

  -S /tmp/starman.sock

Specifies the path to UNIX domain socket to bind.

This option is for a compatibility with plackup and you're recommended to use --listen instead.

--workers

Specifies the number of worker pool. Defaults to 5.

Starman by default sets up other spare server configuration based on this workers value, making sure there are always only N worker processes running. So even if there're no idle workers, Starman won't spawn off spare processes since that's mostly what you want to do by fine tuning the memory usage etc. in the production environment.

--backlog

Specifies the number of backlog (listen queue size) of listener sockets. Defaults to 1024.

On production systems, setting a very low value can allow failover on frontend proxy (like nginx) to happen more quickly, if you have multiple Starman clusters.

If you're doing simple benchmarks and getting connection errors, increasing this parameter can help avoid them. You should also consider increasing net.core.somaxconn. Note that this is not recommended for real production system if you have another cluster to failover (see above).

--max-requests

Number of the requests to process per one worker process. Defaults to 1000.

--preload-app

This option lets Starman preload the specified PSGI application in the master parent process before preforking children. This allows memory savings with copy-on-write memory management. When not set (default), forked children loads the application in the initialization hook.

Enabling this option can cause bad things happen when resources like sockets or database connections are opened at load time by the master process and shared by multiple children.

Since Starman 0.2000, this option defaults to false, and you should explicitly set this option to preload the application in the master process.

Alternatively, you can use -M command line option (plackup's common option) to preload the modules rather than the <application> itself.

  starman -MCatalyst -MDBIx::Class myapp.psgi

will load the modules in the master process for memory savings with CoW, but the actual loading of myapp.psgi is done per children, allowing resource managements such as database connection safer.

If you enable this option, sending HUP signal to the master process will not pick up any code changes you make. See "Signals" for details.

--disable-keepalive

Disable Keep-alive persistent connections. It is an useful workaround if you run Starman behind a broken frontend proxy that tries to pool connections more than a number of backend workers (i.e. Apache mpm_prefork + mod_proxy).

--keepalive-timeout

The number of seconds Starman will wait for a subsequent request before closing the connection if Keep-alive persistent connections are enabled. Setting this to a high value may cause performance problems in heavily loaded servers. The higher the timeout, the more backend workers will be kept occupied waiting on connections with idle clients.

Defaults to 1.

--read-timeout

The number of seconds Starman will wait for a request on a new connection before closing it. Setting this to a high value may cause performance problems in heavily loaded servers. The higher the timeout, the more backend workers will be kept occupied waiting on connections with idle clients. You may need this if your proxy / load balancer likes to keep a pool of open connections while waiting for clients (eg. Amazon ELB).

Defaults to 5.

--user

To listen on a low-numbered (<1024) port, it will be necessary to start the server as root. Use the --user option to specify a userid or username that the server process should switch to after binding to the port.

Defaults to the current userid.

--group

Specify the group id or group name that the server should switch to after binding to the port.  This option is usually used with --user.

Defaults to the current group id.

--pid

Specify the pid file path. Use it with -D|--daemonize option, described in plackup -h.

--error-log

Specify the pathname of a file where the error log should be written. This enables you to still have access to the errors when using --daemonize.

--ssl-cert

Specify the path to SSL certificate file.

--ssl-key

Specify the path to SSL key file.

--enable-ssl

Enable SSL on all TCP sockets. This is an experimental feature.

--disable-proctitle

Disable the behavior to set proctitle to "starman (master)" and "starman (worker)" respectively on master and workers.

Starman passes through other options given to Plack::Runner, the common backend that plackup uses, so the most options explained in plackup -h such as --access-log or --daemonize works fine in starman too.

Setting the environment variable STARMAN_DEBUG to 1 makes the Starman server running in the debug mode.

HUP

Sending HUP signal to the master process will restart all the workers gracefully (meaning the currently running requests will shut down once the request is complete), and by default, the workers will pick up the code changes you make by reloading the application.

If you enable --preload-app option, however, the code will be only loaded in the startup process and will not pick up the code changes you made. If you want to preload the app and do graceful restarts by reloading the code changes, you're recommended to use Server::Starter, configured to send QUIT signal when superdaemon received HUP, i.e:

    start_server --interval 5 --port 8080 --signal-on-hup=QUIT -- \
      starman --preload-app myapp.psgi

You will then send the HUP signal to start_server process to gracefully reload the starman cluster (master and workers).

With Server::Starter 0.12 or later, you should also be able to set --signal-on-term to QUIT so that you can safely shutdown Starman first and then stop the start_server daemon process as well.

TTIN, TTOU

Sending TTIN signal to the master process will dynamically increase the number of workers, and TTOU signal will decrease it.

INT, TERM

Sending INT or TERM signal to the master process will kill all the workers immediately and shut down the server.

QUIT

Sending QUIT signal to the master process will gracefully shutdown the workers (meaning the currently running requests will shut down once the request is complete).

You're recommended to use signals (see above) to reload the application, and are strongly discouraged to use -r or -R (reloading flag) from plackup. These options will make a separate directory watcher process, and makes your life difficult if you want to combine with other process daemon tools such as Server::Starter.

starman executable is basically the equivalent of using plackup with Starman server handler i.e. plackup -s Starman, except that starman delay loads the application with the Delayed loader by default, which can be disabled with --preload-app.

starman command also automatically sets the environment (-E) to the value of deployment.

You're recommended to use starman unless there's a reason to stick to plackup for compatibility.

Starman

public-inbox-daemon(8).