NAME
thrall - Simple PSGI/Plack HTTP server that uses threads
SYNOPSIS
$ thrall --max-workers=20 --max-reqs-per-child=100 app.psgi
$ thrall --port=80 --ipv6=1 app.psgi
$ thrall --port=443 --ssl=1 --ssl-key-file=file.key --ssl-cert-file=file.crt app.psgi
$ thrall --socket=/tmp/thrall.sock app.psgiDESCRIPTION
Thrall is a standalone HTTP/1.1 server with keep-alive support. It uses threads instead pre-forking, so it works correctly on Windows. It is a pure-Perl implementation that doesn't require any XS package.
Thrall was started as a fork of Starlet server. It has almost the same code as Starlet and it was adapted to use threads instead fork().
OPTIONS
In addition to the options supported by plackup, thrall accepts following options(s).
--access-log
Specifies the pathname of a file where the access log should be written. By default, in the development environment access logs will go to STDERR. See plackup. (default: none)
--daemonize
Makes the process run in the background. It doesn't work (yet) in native Windows (MSWin32). (default: 0)
-E, --env
Specifies the environment option. See plackup. (default: "deployment")
--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. (default: none)
--group
Changes the group ids or group names that the server should switch to after binding to the port. The ids or names can be separated with commas or space characters. (default: none)
-o, --host
Binds to a TCP interface. Defaults to undef, which lets most server backends bind to the any (*) interface. This option is only valid for servers which support TCP sockets.
-I
Specifies Perl library include paths, like perl's -I option. You may add multiple paths by using this option multiple times. See plackup.
--ipv6
Enables IPv6 support. The IO::Socket::IP module is required. (default: 1 if IO::Socket::IP is available or 0 otherwise)
--keepalive-timeout
Timeout for persistent connections. (default: 2)
-L, --loader
Starlet changes the default loader to Delayed to make lower consumption of the children and prevent problems with shared IO handlers. It might be set to Plack::Loader to restore the default loader.
-M
Loads the named modules before loading the app's code. You may load multiple modules by using this option multiple times. See plackup. (default: none)
--main-process-delay
The Thrall does not synchronize its processes and it requires a small delay in main process so it doesn't consume all CPU. (default: 0.1)
--max-keepalive-reqs
Max. number of requests allowed per single persistent connection. If set to one, persistent connections are disabled. (default: 1)
--max-reqs-per-child
Max. number of requests to be handled before a worker process exits. (default: 1000)
--max-workers
A number of worker threads. (default: 10)
--min-reqs-per-child
If set, randomizes the number of requests handled by a single worker process between the value and that supplied by --max-reqs-per-chlid. (default: none)
-p, --port
Binds to a TCP port. Defaults to 5000. This option is only valid for servers which support TCP sockets.
Note: default port 5000 may conflict with AirPlay server on MacOS 12 (Monterey) or later.
--pid
Specify the pid file path. Use it with -D|--daemonize option. (default: none)
-q, --quiet
Suppress the message about starting a server.
-r, --reload
Makes plackup restart the server whenever a file in your development directory changes. See plackup. (default: none)
-R, --Reload
Makes plackup restart the server whenever a file in any of the given directories changes. See plackup. (default: none)
--socket
Enables UNIX socket support. The IO::Socket::UNIX module is required. The socket file has to be not yet created. The first character @ or \0 in the socket file name means that an abstract socket address will be created. (default: none)
--spawn-interval
If set, worker processes will not be spawned more than once every given second. Also, when SIGHUP is being received, no more than one worker process will be collected every given second. This feature is useful for doing a "slow restart". (default: none)
--ssl
Enables SSL support. The IO::Socket::SSL module is required. (default: 0)
--ssl-ca-file
Specifies the path to the SSL CA certificate file which will be a part of server's certificate chain. (default: none)
--ssl-cert-file
Specifies the path to the SSL certificate file. (default: none)
--ssl-client-ca-file
Specifies the path to the SSL CA certificate file for client verification. (default: none)
--ssl-key-file
Specifies the path to the SSL key file. (default: none)
--ssl-verify-mode
Specifies the verification mode for the client certificate. See "SSL_verify_mode" in IO::Socket::SSL for details. (default: 0)
--timeout
Seconds until timeout. (default: 300)
--umask
Changes file mode creation mask. The "umask" in perlfunc is an octal number representing disabled permissions bits for newly created files. It is usually 022 when a group shouldn't have permission to write or 002 when a group should have permission to write. (default: none)
--user
Changes the user id or user name that the server process should switch to after binding to the port. The pid file, error log or unix socket also are created before changing privileges. This option is usually used if the main process is started with root privileges because binding to the low-numbered (<1024) port. (default: none)
SEE ALSO
LIMITATIONS
See "BUGS AND LIMITATIONS" in threads and "Thread-Safety of System Libraries" in perlthrtut to read about limitations for PSGI applications started with Thrall and check if you encountered a known problem.
Especially, PSGI applications should avoid: changing the current working directory, catching signals, and starting new processes. Environment variables might (Linux, Unix) or might not (Windows) be shared between threads.
Thrall is very slow on the first request for each thread. It is because spawning new threads is slow in Perl itself. Thrall is very fast on another request and generally is faster than any implementation which uses fork.
BUGS
There is a problem with Perl threads implementation which occurs on Windows. Some requests can fail with the message:
failed to set socket to nonblocking mode:An operation was attempted on something that is not a socket.
or
Bad file descriptor at (eval 24) line 4.
Cygwin version seems to be correct.
This problem was introduced in Perl 5.16 and fixed in Perl 5.19.5.
See https://rt.perl.org/rt3/Public/Bug/Display.html?id=119003 and https://github.com/dex4er/Thrall/issues/5 for more information about this issue.
MacOS
MacOS High Sierra and newer shows error:
objc[12345]: +[__NSCFConstantString initialize] may have been in progress in another thread when fork() was called. objc[12345]: +[__NSCFConstantString initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.
This error is caused by an added security to restrict multithreading.
To override the limitation, run export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES before using this server.
Reporting
If you find the bug or want to implement new features, please report it at https://github.com/dex4er/Thrall/issues
The code repository is available at http://github.com/dex4er/Thrall
AUTHORS
Piotr Roszatycki <dexter@cpan.org>
Based on Starlet by:
Kazuho Oku
miyagawa
kazeburo
Some code based on Plack:
Tatsuhiko Miyagawa
Some code based on Net::Server::Daemonize:
Jeremy Howard <j+daemonize@howard.fm>
Paul Seamons <paul@seamons.com>
LICENSE
Copyright (c) 2013-2017, 2023 Piotr Roszatycki <dexter@cpan.org>.
This is free software; you can redistribute it and/or modify it under the same terms as perl itself.