Help Center/ MapReduce Service/ Component Operation Guide (LTS)/ Using JobGateway/ Adding JobServer Instances to Master Nodes and Deleting Them from Core Nodes
Updated on 2025-07-16 GMT+08:00
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Adding JobServer Instances to Master Nodes and Deleting Them from Core Nodes

This section applies to MRS 3.3.0-LTS and MRS 3.3.0-LTS.1.

Scenarios

In MRS 3.3.0-LTS and MRS 3.3.0-LTS.1, JobServer instances are deployed on Core nodes by default. JobServer is mainly used to submit jobs, and two instances are enough. You are advised to migrate the instances to Master nodes.

This section applies only to custom clusters. If you use analysis clusters, contact O&M personnel.

Procedure

  1. Add two JobServer instances to Master nodes. Specifically, add one JobServer instance to each of the Master2 and Master3 nodes by default.

    1. Log in to the MRS management console. On the displayed page, click the name of the target MRS cluster.
    2. Click the Components tab. On this tab, click the JobGateway service. On the displayed page, click Instances. Click Add Instance and add JobServer instances to the Master nodes.

      Ensure that Master2 and Master3 nodes each have more than 4 GB of reserved memory. Otherwise, the JobServer instance process may fail to start.

  2. After the instances are added, select the JobBalancer instances on the Instances tab page and choose More > Instance Rolling Restart.

    Perform the rolling restart during off-peak hours to minimize the risks of job submission failures.

  3. Check whether the JobServer instances newly added to the Master nodes are running properly. If not, contact O&M personnel.

    Log in to the Master nodes where the JobServer instances are located and check whether the requests in the /var/log/Bigdata/job-gateway/balance/access_http.log file of each JobBalancer instance are forwarded to the IP addresses of the JobServer instances added to the Master nodes.

  4. Stop the JobServer instances on the Core nodes in batches.

    On the Instances tab page, select a JobServer instance on a Core node and choose More > Stop Instance.

    Stop the instances during off-peak hours to minimize the risks of job submission failures.

  5. Delete the JobServer instances on the Core nodes in batches.

    On the Instances tab page, select a JobServer instance on a Core node, choose More > Delete Instance.

  6. Check whether the JobGateway service is functioning properly by submitting a job on the Jobs tab of the MRS console.
Parent topic: Using JobGateway