浅析关于PHP中Sphinx长连接问题

SphinxClient::open

(PECL sphinx >= 1.0.3)

SphinxClient::open — 建立到搜索服务端的持久连接

说明

public bool SphinxClient::open ( void )

建立到搜索服务端的持久连接.

参数

此函数没有参数。

返回值

成功时返回 TRUE， 或者在失败时返回 FALSE.

今日在做PHP系统代码优化时，对sphinx的长连接做了一些分析发现php的sphinx api并不是我们想象中的那样会在php-fpm的fastcgi状态下一直与sphinx的searchd进程保持长连接，sphinx的api接口中open()方法仅仅提供了在一次会话请求中保证多个sphinx调用在单个php进程中是共用一个sphinx tcp连接通道，当php解释运行完，与sphinx的连接也会自动断开，而不是保持连接状态。

这篇帖子也佐证了楼主的这个想法：http://sphinxsearch.com/forum/view.html?id=7200

> So it seems that the definition of 'persistent connection' in Sphinx is different from

> persistent MySql connections when using a PhP API : the persistence is only across

> multiple calls *in the same php
request execution* and not persistence within the client

> process i.e. across multiple php requests.

我们可以做一个这样的实验来证明我的观点：

给php增加sphinx.so扩展，然后写如下测试代码：

<!--?php<br /-->

$s = new SphinxClient();

var_dump($s);

$s->setServer('192.168.1.108','9312');

//$s->open();

var_dump($s->query('abxxxx'));

var_dump($s->query('abxxxx'));

注意这里$s->open()先屏蔽，然后我们在cli状态下利用strace命令跟踪执行此php脚本，收集系统调用信息会发现：

在系统调用中出现了两次connect到192.168.1.108的请求。也就是说在没调用open方法的时候，在同一个php运行时中会导致两次对sphinx产生的tcp请求。

611 fcntl64(3, F_SETFL, O_RDONLY|O_NONBLOCK) = 0

612 connect(3, {sa_family=AF_INET, sin_port=htons(9312), sin_addr=inet_addr("192.168.1.108")}, 16) = -1 EINPROGRESS (Operation now in progress)

613
select(4, NULL, [3], NULL, {60, 0}) = 1 (out [3], left {59, 999996})

614 fcntl64(3, F_SETFL, O_RDONLY) = 0

615 send(3, "1", 4, MSG_NOSIGNAL) = 4

616 recv(3, "1", 4, 0) = 4

617 send(3, "1312241", 16, MSG_NOSIGNAL) = 16

618 send(3, "246abxx"..., 140, MSG_NOSIGNAL) = 140

619 recv(3, "131`", 8, 0) = 8

620 recv(3, "25title4text2"..., 96, 0) = 96

621 close(3)

。。。。。。。。。。。。。。。。。。。

。。。。。。。。。。。。。。。。。。。

756 socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 3

757 fcntl64(3, F_SETFL, O_RDONLY|O_NONBLOCK) = 0

758 connect(3, {sa_family=AF_INET, sin_port=htons(9312), sin_addr=inet_addr("192.168.1.108")}, 16) = -1 EINPROGRESS (Operation now in progress)

759 select(4, NULL, [3], NULL, {60, 0}) = 1 (out [3], left {59, 999997})

760 fcntl64(3, F_SETFL, O_RDONLY) = 0

761 send(3, "1", 4, MSG_NOSIGNAL) = 4

762 recv(3, "1", 4, 0) = 4

763 send(3, "1312241", 16, MSG_NOSIGNAL) = 16

764 send(3, "246abxx"..., 140, MSG_NOSIGNAL) = 140

765 recv(3, "131`", 8, 0) = 8

766 recv(3, "25title4text2"..., 96, 0) = 96

767 close(3) = 0

768 write(1, "array(9) {n", 11array(9) {

然后我们取消open调用的注释，继续strace，会发现这时候依然是连续调用两次query方法，但在第一次query调用后api不会立即close掉tcp连接，而是继续给到第二次query调用使用。

611 fcntl64(3, F_SETFL, O_RDONLY|O_NONBLOCK) = 0

612 connect(3, {sa_family=AF_INET, sin_port=htons(9312), sin_addr=inet_addr("192.168.1.108")}, 16) = -1 EINPROGRESS (Operation now in progress)

613 select(4, NULL, [3], NULL, {60, 0}) = 1 (out [3], left {59, 999996})

614 fcntl64(3, F_SETFL, O_RDONLY) = 0

615 send(3, "1", 4, MSG_NOSIGNAL) = 4

616 recv(3, "1", 4, 0) = 4

617 send(3, "441", 12, MSG_NOSIGNAL) = 12

618 select(4, [3], NULL, [3], {0, 0}) = 0 (Timeout)

619 send(3, "1312241", 16, MSG_NOSIGNAL) = 16

620 send(3, "246abxx"..., 140, MSG_NOSIGNAL) = 140

621 recv(3, "131`", 8, 0) = 8

622 recv(3, "25title4text2"..., 96, 0) = 96

623 write(1, "array(9) {n", 11array(9) {

624 ) = 11