stream_select timeout on newly opened socket - php

Question

I use thrift php client to connect to java thrift server. But got the error of
TSocket: timed out writing 78 bytes from 10.0.1.151:1234
I dig into the php source of thrift and find it was caused from timeout on function stream_select.
/**
* Write to the socket.
*
* #param string $buf The data to write
*/
public function write($buf)
{
$null = null;
$write = array($this->handle_);
// keep writing until all the data has been written
while (TStringFuncFactory::create()->strlen($buf) > 0) {
// wait for stream to become available for writing
$writable = #stream_select($null, $write, $null, $this->sendTimeoutSec_, $this->sendTimeoutUsec_);
if ($writable > 0) {
// write buffer to stream
$written = #stream_socket_sendto($this->handle_, $buf);
if ($written === -1 || $written === false) {
throw new TTransportException('TSocket: Could not write '.TStringFuncFactory::create()->strlen($buf).' bytes '.
$this->host_.':'.$this->port_);
}
// determine how much of the buffer is left to write
$buf = TStringFuncFactory::create()->substr($buf, $written);
} elseif ($writable === 0) {
throw new TTransportException('TSocket: timed out writing '.TStringFuncFactory::create()->strlen($buf).' bytes from '.
$this->host_.':'.$this->port_);
} else {
throw new TTransportException('TSocket: Could not write '.TStringFuncFactory::create()->strlen($buf).' bytes '.
$this->host_.':'.$this->port_);
}
}
}
That means the socket was blocked and was not able to write. But the socket is just open and should not be blocked. I try select immediately after pfsockopen
if ($this->persist_) {
$this->handle_ = #pfsockopen($this->host_,
$this->port_,
$errno,
$errstr,
$this->sendTimeoutSec_ + ($this->sendTimeoutUsec_ / 1000000));
} else {
$this->handle_ = #fsockopen($this->host_,
$this->port_,
$errno,
$errstr,
$this->sendTimeoutSec_ + ($this->sendTimeoutUsec_ / 1000000));
}
// Connect failed?
if ($this->handle_ === FALSE) {
$error = 'TSocket: Could not connect to '.$this->host_.':'.$this->port_.' ('.$errstr.' ['.$errno.'])';
if ($this->debug_) {
call_user_func($this->debugHandler_, $error);
}
throw new TException($error);
}
$write = array($this->handle_);
$writable = #stream_select($null, $write, $null, $this->sendTimeoutSec_, $this->sendTimeoutUsec_);
if ($writable === 0) {
die('123');
}
The result show that it is block right after it is opened!
When restart php-fpm, the error disappear for a while and come up again.
Here is the client code:
$socket = new TSocket('10.0.1.151', 1234, true);
$framedSocket = new TFramedTransport($socket);
$transport = $framedSocket;
$protocol = new TCompactProtocol($transport);
$transport->open();
$client= new userservice\UserServiceProxyClient($protocol);
$result = $client->findUser($id);
If I adjust the php-fpm configuration pm.max_children from 200 to 2, the error also disappear.
I tried increase timeout to 10 seconds and it timeout after 10 seconds.
Any idea for what's the cause of the problem and how to fix it?

Answer 1

I modify the php thrift lib. Change from
$writable = #stream_select($null, $write, $null, $this->sendTimeoutSec_, $this->sendTimeoutUsec_);
to
$writable = 1;
And the same for read.
The problem get fixed.
That means the connection is established ( I even use tcpdump to confirm the tcp connection is established) and writable, but select timeout. Strange things!