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Jenkins pipeline控制并行执行job个数

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pipeline中,可以通过parallel,并行跑多个job。但是如果想限制并行跑的job个数,应该如何做呢?

比如说有10个job,要并行跑,但是目前资源有限,只允许最多3个同时跑,那这种情况下,应该如何修改Jenkinsfile,来满足这个需求?

通过自己的摸索,发现用以下方法,可以实现。

下图有6个job,test1-test6,这6个job,是希望并行跑的,但是在一个时刻,最多只有2个job能够并行跑。

直接上Jenkinsfile代码:

pipeline {

    agent any

    stages {

        stage("parallel test") {

            steps {

                script {

                    def branches = [:]

                    MAX_CONCURRENT = 2

                    //创建fifo

                    latch = new java.util.concurrent.LinkedBlockingDeque(MAX_CONCURRENT)

                    

                    //往fifo中,填入最大个数元素

                    for(int i=0; i<MAX_CONCURRENT; i++)

                        latch.offer("$i")

                    

                    def job_list = [

                        "test1",

                        "test2",

                        "test3",

                        "test4",

                        "test5",

                        "test6"

                    ]

                    

                    for(int i=0; i<job_list.size(); i++) {

                        def name = job_list[i]

                        branches[name] = {

                            def thing = null

                            waitUntil {

                                //获取一个资源

                                thing = latch.pollFirst();

                                return thing != null;

                            }

                            try {

                                //执行job

                                build(job: name, propagate: false)

                            }

                            finally {

                                //释放一个资源

                                latch.offer(thing)

                            }        

                        }

                    }

                    timestamps {

                        parallel branches

                    }

                }

            }

        }

    }

}

本质上,利用了java的LinkedBlockingDeque这个类,以下网站是介绍这个类:

http://tool.oschina.net/uploads/apidocs/jdk-zh/java/util/concurrent/LinkedBlockingDeque.html

将以上代码,写入到pipeline job配置的pipeline选项框中,注意,不能勾选Use Groovy Sandbox。

当然也可以把代码,写入到Jenkinsfile文件中,然后执行job需要执行的Jenkinsfile即可。

执行log如下,test1和test2首先执行,能够获取到资源,得到执行,之后的job,获取不到资源,然后被阻塞。

test1和test2执行完毕后,会释放资源,test3和test4获取到资源,然后开始执行。

执行完后,blueocean显示如下:

从blueocean看出,test1和test6是并行执行的,但是在真实环境中,他们并不是同时执行的。