Introduction

The use of the word ‘Jenkins’ typically refers to the Jenkins Controller (formerly ‘Master’) which is the central build process coordinator that stores configuration and renders the various Jenkins user interfaces. This Controller achieves its aims using a combination of local and remote resources, the latter of which are made available to the Controller through Agents (formerly ‘Slaves’) that are processes sitting on various machines on your network.

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Executors: An executor is a slot for execution of tasks; effectively, it is a thread in the agent. The number of executors on a node defines the number of concurrent tasks that can be executed on that node at one time. In other words, this determines the number of concurrent Pipeline stages that can execute on that node at one time. Data Migrators do not recommend running more than one Executor per Jenkins Node as this could permit the definition of Pipelines which cause to resource contention with underlying DataStage components.

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Assigning Pipeline operations to specific Agents using Labels

In the case of the supplied Upgrade Pipeline certain Pipeline operations need to happen in specific Agents - i.e. some operations must execute on your environment’s legacy Agent, whilst others need to be assigned to a target Agent. To achieve this the MettleCI Sample Jenkins Pipeline assumes the availability of two Agent labels which you should have created and assigned:

You’ll see the labels used in the Pipeline definitions like this:

stages {
    stage("Some Pipeline Stage") {
        agent {
            label 'mettleci:datastage11.5.1'
        }
        environment {
            ENVID = "ci"
            DATASTAGE_PROJECT = "${env.IIS_BASE_PROJECT_NAME}_${env.ENVID}"
        }
        steps { ... }           

Note that the DevOps Pipeline only assumes the presence of a single Agent with the