stream_select(): You MUST recompile PHP with a larger value of FD_SETSIZE

[monsieurchico]

Hello,

I known there already are closed issues on the subject but I encounter this error on one of my project. I tried to downgrade the version to 2.7.0 and it worked.

But it's not really a reliable solution....

May be a retry system could be implemented ?

My stack :

• php 7.1.28 (docker alpine version)
• symfony 4.2
• swarrot bundle

The full error :

[2019-05-22 11:23:38] app.ERROR: Uncaught exception of type PhpAmqpLib\Exception\AMQPIOWaitException {"exception_message":"stream_select(): You MUST recompile PHP with a larger value of FD_SETSIZE.\nIt is set to 1024, but you have descriptors numbered at least as high as 1610.\n --enable-fd-setsize=2048 is recommended, but you may want to set it\nto equal the maximum number of open files supported by your system,\nin order to avoid seeing this error again at a later date.","class":"PhpAmqpLib\Exception\AMQPIOWaitException","code":0,"file":"/app/vendor/php-amqplib/php-amqplib/PhpAmqpLib/Wire/IO/AbstractIO.php:89","app_code":"INTERNAL_SERVER_ERROR"} []

[ramunasd]

Hi @monsieurchico , can You try latest version with disabled tcp_nodelay ? I think #517 is the only one change which can cause this type of error.

[monsieurchico]

How can I disable tcp_nodelay ?

[ramunasd]

$context = stream_context_create();
$connection = new AMQPStreamConnection($host, $port, $user, $password, $vhost, false, 'AMQPLAIN', null, 'en_US', 3, 130, $context);

[monsieurchico]

Is there a way to do it in swarrot ?

[ramunasd]

@monsieurchico please ask there :)

[lukebakken]

Assuming addressed by @ramunasd 's comment here.

[ym2048]

@lukebakken I also meet the problem。Our enviroment is as follow:
php: 7.1.2
php-amqplib：2.11.0

I tried your suggestion，
$context = stream_context_create();
$connection = new AMQPStreamConnection($host, $port, $user, $password, $vhost, false, 'AMQPLAIN', null, 'en_US', 3, 130, $context);

create a stream_context object and pass into AMQPStreamConnection construction method,
but it doesn't solve the probleam.

Can you give me more suggestion, thank you very mush!

[ym2048]

@monsieurchico
we also downgrade the version to 2.7.0, is that you final solution?

[ramunasd]

@ym2048 can You prepare example on how to reproduce this issue?

[ym2048]

@ramunasd we tried millions times using apache ab tool in development environment, but we did not reproduce the problem. in product environment, it occurs frequently

[ramunasd]

@ym2048 So in which sapi you get this error? CLI or CGI?
I guess there is something wrong in Your client code. You either spinning up too much processes or each process opens too much connections. Single process single connection consumes only one file descriptor.

More context:
https://bugs.php.net/bug.php?id=69637
https://bugs.php.net/bug.php?id=37025

[gitsrc]

Centos operating system can try to adjust the LimitNPROC parameter of systemd or kernel。

# Specifies the maximum number of processes
LimitNPROC=4096