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Starman(3pm) User Contributed Perl Documentation Starman(3pm)


Starman - High-performance preforking PSGI/Plack web server


  # Run app.psgi with the default settings
  > starman
  # run with Server::Starter
  > start_server --port -- starman --workers 32 myapp.psgi
  # UNIX domain sockets
  > starman --listen /tmp/starman.sock

Read more options and configurations by running `perldoc starman` (lower-case s).


Starman is a PSGI perl web server that has unique features such as:

Uses the fast XS/C HTTP header parser
Spawns workers preforked like most high performance UNIX servers do. Starman also reaps dead children and automatically restarts the worker pool.
Supports "HUP" for graceful worker restarts, and "TTIN"/"TTOU" to dynamically increase or decrease the number of worker processes, as well as "QUIT" to gracefully shutdown the worker processes.
Supports Server::Starter for hot deploy and graceful restarts.
Able to listen on multiple interfaces including UNIX sockets.
Preloading the applications with "--preload-app" command line option enables copy-on-write friendly memory management. Also, the minimum memory usage Starman requires for the master process is 7MB and children (workers) is less than 3.0MB.
Can run any PSGI applications and frameworks
Supports chunked requests and responses, keep-alive and pipeline requests.
This server does not support Win32.


Here's a simple benchmark using "Hello.psgi".

  -- server: Starman (workers=10)
  Requests per second:    6849.16 [#/sec] (mean)
  -- server: Twiggy
  Requests per second:    3911.78 [#/sec] (mean)
  -- server: AnyEvent::HTTPD
  Requests per second:    2738.49 [#/sec] (mean)
  -- server: HTTP::Server::PSGI
  Requests per second:    2218.16 [#/sec] (mean)
  -- server: HTTP::Server::PSGI (workers=10)
  Requests per second:    2792.99 [#/sec] (mean)
  -- server: HTTP::Server::Simple
  Requests per second:    1435.50 [#/sec] (mean)
  -- server: Corona
  Requests per second:    2332.00 [#/sec] (mean)
  -- server: POE
  Requests per second:    503.59 [#/sec] (mean)

This benchmark was processed with "ab -c 10 -t 1 -k" on MacBook Pro 13" late 2009 model on Mac OS X 10.6.2 with perl 5.10.0. YMMV.


Because Starman runs as a preforking model, it is not recommended to serve the requests directly from the internet, especially when slow requesting clients are taken into consideration. It is suggested to put Starman workers behind the frontend servers such as nginx, and use HTTP proxy with TCP or UNIX sockets.



Starman exposes a callback named "psgix.informational" that can be used for sending an informational response. The callback accepts two arguments, the first argument being the status code and the second being an arrayref of the headers to be sent. Example below sends an 103 Early Hints response before processing the request to build a final response.

    sub {
        my $env = shift;
        $env->{'psgix.informational'}->( 103, [
            "Link" => "</style.css>; rel=preload"
        ] );
        my $rest = ...


Tatsuhiko Miyagawa <>

Andy Grundman wrote Catalyst::Engine::HTTP::Prefork, which this module is heavily based on.

Kazuho Oku wrote Net::Server::SS::PreFork that makes it easy to add Server::Starter support to this software.

The "psgix.informational" callback comes from Starlet by Kazuho Oku.


Tatsuhiko Miyagawa, 2010-


This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.


Plack Catalyst::Engine::HTTP::Prefork Net::Server::PreFork

2023-09-14 perl v5.40.0