Edit report at https://bugs.php.net/bug.php?id=74178&edit=1
ID: 74178
User updated by: alex at alex-at dot ru
Reported by: alex at alex-at dot ru
Summary: Suggestion/Idea: Stateful / Application Script
Status: Open
Type: Feature/Change Request
Package: FPM related
PHP Version: Next Major Version
Block user comment: N
Private report: N
New Comment:
Elaborating further (of course don't know if the idea is viable as a whole, but nevertheless).
max_execution_time may (should) be counted anew for each request. Something like
max_stateful_execution_time should control total execution time, but only inside run_as_stateful()
code, not at any moment, to make sure last request is complete.
run_as_stateful() never exits but may also be extended with optional $eventHandler and
$eventInterval. If no requests come under $eventInterval microseconds, $eventHandler callback may be
called to process i.e. external ZeroMQ or other events periodically, updating internal state.
From scripts developer perspective, applications handling a lot of state and serving lots of clients
would benefit a lot from lack of 1) code reloading, 2) PHP engine initialization, 3) internal class
reinitialization. Some messaging queues like ZeroMQ can also be used to synchronize state between
running stateful scripts, reducing need to reload any state even further. Also similar mechanisms
can potentially be used for i.e. websocket handling in parallel with handling requests.
Previous Comments:
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[2017-02-27 18:34:41] alex at alex-at dot ru
Description:
------------
Many current PHP scripts suffer from necessity of (re)initializing lots of state from startup to
real serving. Even using Opcache/Memcached/whatever, initialization of all database/cache/etc.
connections and classes takes ages.
So why just not bring common 'appserver' paradigm to PHP?
Basically, it all boils to implementation of a single function: run_as_stateful($callback, $timeout
= null) or something like that.
What should it do: it should clean up all volatile request and session variables, and make server
know script is ready to accept new request to it. Everything else related to process should remain
intact: variables, classes, objects, database/cache connections, open files, other resources,
whatever.
When a new request to the same script comes, and there is some stateful script process idling,
request gets scheduled to one of these processes. Request variables get filled (session ones do not,
until new session_start call in PHP code), and $callback gets executed. Basically, that's all.
This will allow $callback to skip all the unnecessary initialization, getting through only to
request-based serving.
Once $callback executes, it can either "exit", causing script process to terminate, or
just "return", causing script to wait for a new request, or call run_as_stateful() anew,
refreshing $timeout. Any error of course causes script process to terminate.
$timeout here is a timeout for script process to be waiting for requests (idling) in total (each
period counts, or may be refreshed within $callback), after which process terminates.
If there are no running stateful script processes at the moment of request, request is scheduled to
normal PHP execution strategy, without any changes required.
File change detection can be optionally either ignored or delegated to opcache with its change
detection strategy, and terminate all idling stateful script processes / set terminate flag to all
running stateful script processes so they terminate at next idle loop.
The idea/suggestion is mainly intended for FPM I think, because it has process control and can be
extended with any tunables needed, like maximum lifetime of a stateful script, maximum count of
stateful scripts running (total and per script), list of scripts that are allowed to run as
stateful, etc.
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Edit this bug report at https://bugs.php.net/bug.php?id=74178&edit=1