问题
Problem: I want to implement several php-worker processes who are listening on a MQ-server queue for asynchronous jobs. The problem now is that simply running this processes as daemons on a server doesn't really give me any level of control over the instances (Load, Status, locked up)...except maybe for dumping ps -aux. Because of that I'm looking for a runtime environment of some kind that lets me monitor and control the instances, either on system (process) level or on a higher layer (some kind of Java-style appserver)
Any pointers?
回答1:
Here's some code that may be useful.
<?
define('WANT_PROCESSORS', 5);
define('PROCESSOR_EXECUTABLE', '/path/to/your/processor');
set_time_limit(0);
$cycles = 0;
$run = true;
$reload = false;
declare(ticks = 30);
function signal_handler($signal) {
switch($signal) {
case SIGTERM :
global $run;
$run = false;
break;
case SIGHUP :
global $reload;
$reload = true;
break;
}
}
pcntl_signal(SIGTERM, 'signal_handler');
pcntl_signal(SIGHUP, 'signal_handler');
function spawn_processor() {
$pid = pcntl_fork();
if($pid) {
global $processors;
$processors[] = $pid;
} else {
if(posix_setsid() == -1)
die("Forked process could not detach from terminal\n");
fclose(stdin);
fclose(stdout);
fclose(stderr);
pcntl_exec(PROCESSOR_EXECUTABLE);
die('Failed to fork ' . PROCESSOR_EXECUTABLE . "\n");
}
}
function spawn_processors() {
global $processors;
if($processors)
kill_processors();
$processors = array();
for($ix = 0; $ix < WANT_PROCESSORS; $ix++)
spawn_processor();
}
function kill_processors() {
global $processors;
foreach($processors as $processor)
posix_kill($processor, SIGTERM);
foreach($processors as $processor)
pcntl_waitpid($processor);
unset($processors);
}
function check_processors() {
global $processors;
$valid = array();
foreach($processors as $processor) {
pcntl_waitpid($processor, $status, WNOHANG);
if(posix_getsid($processor))
$valid[] = $processor;
}
$processors = $valid;
if(count($processors) > WANT_PROCESSORS) {
for($ix = count($processors) - 1; $ix >= WANT_PROCESSORS; $ix--)
posix_kill($processors[$ix], SIGTERM);
for($ix = count($processors) - 1; $ix >= WANT_PROCESSORS; $ix--)
pcntl_waitpid($processors[$ix]);
} elseif(count($processors) < WANT_PROCESSORS) {
for($ix = count($processors); $ix < WANT_PROCESSORS; $ix++)
spawn_processor();
}
}
spawn_processors();
while($run) {
$cycles++;
if($reload) {
$reload = false;
kill_processors();
spawn_processors();
} else {
check_processors();
}
usleep(150000);
}
kill_processors();
pcntl_wait();
?>
回答2:
It sounds like you already have a MQ up and running on a *nix system and just want a way to manage workers.
A very simple way to do so is to use GNU screen. To start 10 workers you can use:
#!/bin/sh
for x in `seq 1 10` ; do
screen -dmS worker_$x php /path/to/script.php worker$x
end
This will start 10 workers in the background using screens named worker_1,2,3 and so on.
You can reattach to the screens by running screen -r worker_ and list the running workers by using screen -list.
For more info this guide may be of help: http://www.kuro5hin.org/story/2004/3/9/16838/14935
Also try:
- screen --help
- man screen
- or google.
For production servers I would normally recommend using the normal system startup scripts, but I have been running screen commands from the startup scripts for years with no problems.
回答3:
Do you actually need it to be continuously running?
If you only want to spawn new process on request, you can register it as a service in xinetd.
回答4:
a pcntl plugin type server daemon for PHP
http://dev.pedemont.com/sonic/
回答5:
Bellow is our working implementation of @chaos answer. Code to handle signals was removed as this script lives usually just few milliseconds.
Also, in code we added 2 functions to save pids between calls: restore_processors_state() and save_processors_state(). We've used redis there, but you can decide to use implementation on files.
We run this script every minute using cron. Cron checks if all processes alive. If not - it re-run them and then dies. If we want to kill existing processes then we simply run this script with argument kill: php script.php kill.
Very handy way of running workers without injecting scripts into init.d.
<?php
include_once dirname( __FILE__ ) . '/path/to/bootstrap.php';
define('WANT_PROCESSORS', 5);
define('PROCESSOR_EXECUTABLE', '' . dirname(__FILE__) . '/path/to/worker.php');
set_time_limit(0);
$run = true;
$reload = false;
declare(ticks = 30);
function restore_processors_state()
{
global $processors;
$redis = Zend_Registry::get('redis');
$pids = $redis->hget('worker_procs', 'pids');
if( !$pids )
{
$processors = array();
}
else
{
$processors = json_decode($pids, true);
}
}
function save_processors_state()
{
global $processors;
$redis = Zend_Registry::get('redis');
$redis->hset('worker_procs', 'pids', json_encode($processors));
}
function spawn_processor() {
$pid = pcntl_fork();
if($pid) {
global $processors;
$processors[] = $pid;
} else {
if(posix_setsid() == -1)
die("Forked process could not detach from terminal\n");
fclose(STDIN);
fclose(STDOUT);
fclose(STDERR);
pcntl_exec('/usr/bin/php', array(PROCESSOR_EXECUTABLE));
die('Failed to fork ' . PROCESSOR_EXECUTABLE . "\n");
}
}
function spawn_processors() {
restore_processors_state();
check_processors();
save_processors_state();
}
function kill_processors() {
global $processors;
foreach($processors as $processor)
posix_kill($processor, SIGTERM);
foreach($processors as $processor)
pcntl_waitpid($processor, $trash);
unset($processors);
}
function check_processors() {
global $processors;
$valid = array();
foreach($processors as $processor) {
pcntl_waitpid($processor, $status, WNOHANG);
if(posix_getsid($processor))
$valid[] = $processor;
}
$processors = $valid;
if(count($processors) > WANT_PROCESSORS) {
for($ix = count($processors) - 1; $ix >= WANT_PROCESSORS; $ix--)
posix_kill($processors[$ix], SIGTERM);
for($ix = count($processors) - 1; $ix >= WANT_PROCESSORS; $ix--)
pcntl_waitpid($processors[$ix], $trash);
}
elseif(count($processors) < WANT_PROCESSORS) {
for($ix = count($processors); $ix < WANT_PROCESSORS; $ix++)
spawn_processor();
}
}
if( isset($argv) && count($argv) > 1 ) {
if( $argv[1] == 'kill' ) {
restore_processors_state();
kill_processors();
save_processors_state();
exit(0);
}
}
spawn_processors();
来源：https://stackoverflow.com/questions/752214/php-daemon-worker-environment