Question

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?

Answer 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(); ?>