Restricting the Maximum Number of Maps for Hive Tasks

Scenario

• This function applies to Hive.
• This function is used to limit the maximum number of maps for Hive tasks on the server to avoid performance deterioration caused by overload of the HiveSever service.

Procedure

1. The Hive service configuration page is displayed.
   • For versions earlier than MRS 3.x, click the cluster name. On the cluster details page that is displayed, choose Components > Hive > Service Configuration, and select All from the Basic drop-down list.
     

     If the Components tab is unavailable, complete IAM user synchronization first. (On the Dashboard page, click Synchronize on the right side of IAM User Sync to synchronize IAM users.)

   • For MRS 3.x or later, log in to FusionInsight Manager. For details, see Accessing FusionInsight Manager (MRS 3.x or Later). And choose Cluster > Name of the desired cluster > Services > Hive > Configurations > All Configurations.

2. Choose MetaStore(Role) > Customization, add a customized parameter to the hivemetastore-site.xml parameter file, set Name to hive.mapreduce.per.task.max.splits, and set the parameter to a large value. Restart all Hive instances after the modification.