Gearman client failed in webpage,but succeed in command line interface? - c++

Question

The client.php example using command "php client.php" , in http://gearman.org/getting-started/ can successfully communicate to worker.php, but using in webbrowser failed to communicated to worker.php, Does anyone know why and how to configure the gearmand or work around?
OS:CentOS 6.7
Gearmand version:1.1.8.
Gearmand started with "gearmand -l stderr --verbose DEBUG"
when Clients communicate using "gearman -f work < /somedir/somefile" command, the information return as predicted, terminal displays informations as follow,
DEBUG 2015-10-30 11:56:01.371309 [ 1 ] Received GEARMAN_GRAB_JOB_ALL ::58ca:3fa1:77f:0%4234047483:2705334353 -> libgearman-server/thread.cc:310
DEBUG 2015-10-30 11:56:01.371317 [ 1 ] ::58ca:3fa1:77f:0%4234047483:41704 Watching POLLIN -> libgearman-server/gearmand_thread.cc:151
DEBUG 2015-10-30 11:56:01.371334 [ proc ] ::58ca:3fa1:77f:0%4234047483:41704 packet command GEARMAN_CAN_DO -> libgearman-server/server.cc:111
DEBUG 2015-10-30 11:56:01.371344 [ proc ] Registering function: work -> libgearman-server/server.cc:522
DEBUG 2015-10-30 11:56:01.371352 [ proc ] ::58ca:3fa1:77f:0%4234047483:41704 packet command GEARMAN_GRAB_JOB_ALL -> libgearman-server/server.cc:111
DEBUG 2015-10-30 11:56:01.371371 [ 1 ] Received RUN wakeup event -> libgearman-server/gearmand_thread.cc:610
but when webbrowser navigates to "http://localhost/client.php",no information showed in web browser, terminal displays nothing too.
information in error.log of nginx as follow:
2015/10/30 04:59:10 [error] 2756#0: *2 FastCGI sent in stderr: "PHP message: PHP Warning: GearmanClient::doNormal(): send_packet(GEARMAN_COULD_NOT_CONNECT) Failed to send server-options packet -> libgearman/connection.cc:485 in /usr/share/nginx/html/client.php on line 4" while reading response header from upstream, client: 127.0.0.1, server: localhost, request: "GET /client.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "localhost"
[root#localhost html]# cat client.php
<?php
$client= new GearmanClient();
$client->addServer("127.0.0.1",4730);
print $client->doNormal("reverse", "Hello World!");
?>
[root#localhost html]# cat worker.php
<?php
$worker= new GearmanWorker();
$worker->addServer("127.0.0.1",4730);
$worker->addFunction("reverse", "my_reverse_function");
while ($worker->work());
function my_reverse_function($job)
{
return strrev($job->workload());
}
?>
maybe the problem is that the webpage has limits or permission on socket operation?
I think configuration with --http-port option maybe now not mature and stable,So my prefered solution is that php webpages as client can submit job directly to Gearmand, to be processed by a C++ complied worker program. And the c++ worker program should serve many request without call and run and exit per request to save time.
Can this solution possible.
Please help me.
Thanks a lot!

Answer 1

With guidance from tom and Wali Usmani and Clint, finally the Cause was narrowed down to the permission problem in SELinux.
Details can be refered to https://groups.google.com/forum/#!topic/gearman/_dW8SRWAonw.
many thanks to tom and Wali Usmani and Clint.