Gearman Summary

为什么要用 gearman

gearman 非常适合来做异步的任务调度和分发，我们项目组采用gearman来做性能优化，将耗时上报、更新db、更新redis等相关的封装成一个个job ,采用doBackground提交给job server 集群, 启动多个job worker来从job server 集群拉取job进行处理。

gearman的内部机制

gearman 分为 client 、server 和 worker 3 个角色，client 将job 提交给server ,server 将job 派发给空闲的worker，3个通过tcp来通讯。 使用gearman需要安装一个gearman server , 负责接收客户端提交的job,job默认保存在内存中， job可以持久化到mysql 等storage里面，保证job server 重启数据不丢，下面整理下linux开发机上相关的安装。

gcc 版本

gcc version 4.9.4 (GCC)

安装依赖

boost
yum install boost-devel

gperf
yum install gperf

libevent
yum install libevent-devel

libuuid
yum install libuuid-devel

gearman server 安装

下载最新的包
wget https://github.com/gearman/gearmand/releases/download/1.1.18/gearmand-1.1.18.tar.gz
tar zxvf gearmand-1.1.18.tar.gz
cd gearmand-1.1.18
./configure make && make install

start gearman server ,myslq 作为持久化

/usr/local/sbin/gearmand -d -Lx.x.x.x -p x –log-file–log-file=/data/logs/gearman/gearmand.log \
–queue-type=MySQL \
–mysql-host=x.x.xx.xx \
–mysql-port=x \ –mysql-user=db_gearman \
–mysql-password=pwd \
–mysql-db=user ;

php gearman 扩展安装

wget http://pecl.php.net/get/gearman-1.1.2.tgz tar zxf gearman-1.1.2.tgz
/usr/php/bin/phpize
./configure –with-php-config=/usr/php/bin/php-config
make && make install

测试gearman

php worker

<?php    
$worker = new GearmanWorker();  
$worker->addServer("127.0.0.1", '4730');  
$worker->addFunction("reverse", "reverse_fn");      
while (1) {  
    print "Waiting for job...\n";  
    $ret = $worker->work();  
    if ($worker->returnCode() != GEARMAN_SUCCESS) {  
        break;    
    }  
}    
function reverse_fn(GearmanJob $job) {  
    $workload = $job->workload();  
    echo "Received job: " . $job->handle() . "\n";  
    echo "Workload: $workload\n";  
    $result = strrev($workload);  
    echo "Result: $result\n";  
    return $result;  
}  

php client

<?php     
    $client = new GearmanClient();  
    $client->addServer("127.0.0.1", '4730');    
    echo "Sending job\n";  
    $result = $client->doNormal("reverse", "Hello!");  
    if ($result) {  
          echo "Success: $result\n";  
    }

环境迁移注意的问题

线上环境需要和测试环境的保持一致，避免版本不一致带来问题。

###参考文档

• http://gearman.org/