• MapReduce Service

mrs
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  2. MapReduce Service
  3. User Guide
  4. Overview
  5. Limitations

Limitations

Before using MRS, ensure that you have read and understand the following limitations.

  • MRS clusters must be created in VPC subnets.
  • You are advised to use any of the following browsers to access MRS:
    • Google Chrome 36.0 or later
    • Internet Explorer 9.0 or later

      If you use Internet Explorer 9.0, you may fail to log in to the MRS management console because user Administrator is disabled by default in some Windows systems, such as Windows 7 Ultimate. Internet Explorer automatically selects a system user for installation. As a result, Internet Explorer cannot access the management console. You are advised to reinstall Internet Explorer 9.0 or later as the administrator (recommended) or alternatively run Internet Explorer 9.0 as the administrator.

  • To prevent illegal access, only assign access permission for security groups used by MRS where necessary.
  • Do not perform the following operations because they will cause cluster exceptions:
    • Deleting or modifying the default security group that is created when you create an MRS cluster.
    • Powering off, restarting, or deleting cluster nodes displayed in ECS, changing or reinstalling their OS, or modifying their specifications when you use MRS.
    • Deleting the processes, installed applications or files that already exist on the cluster node.
    • Deleting MRS cluster nodes. Deleted nodes will still be charged.
  • If a cluster exception occurs when no incorrect operations have been performed, contact technical support engineers. The technical support engineers will ask you for your key and then perform troubleshooting.
  • MRS clusters are still charged during exceptions. Contact technical support engineers to handle cluster exceptions.
  • Plan disks of cluster nodes based on service requirements. If you want to store a large volume of service data, add EVS disks or storage space to prevent insufficient storage space from affecting node running.
  • The cluster nodes store only users' service data. Non-service data can be stored in the OBS or other ECS nodes.
  • The cluster nodes only run MRS cluster programs. Other client applications or user service programs are deployed on separate ECS nodes.