Tez is a computing framework that is built on Apache Hadoop and supports distributed directed acyclic graphs (DAGs). Tez can use a complex DAG to describe and process big data tasks.

Background information

Tez is used in Apache Hive. Tez serves as a runtime engine of Hive and can optimize the query engine of Hive SQL. Hive on Tez features higher query performance and stability than Hive on MapReduce.

The following figure shows how Hive submits tasks based on MapReduce and Tez.Hive-MapReduce-Tez

For more information about Tez, see Apache TEZ.

Enable the Tez engine

Hive allows you to use Tez to execute SQL statements. Before you execute an SQL statement, you must perform the following steps to enable the Tez engine:

  1. Go to the Cluster Overview page of your cluster.
    1. Log on to the Alibaba Cloud EMR console.
    2. In the top navigation bar, select the region where your cluster resides and select a resource group based on your business requirements.
    3. Click the Cluster Management tab.
    4. On the Cluster Management page, find your cluster and click Details in the Actions column.
  2. In the left-side navigation pane, choose Cluster Service > Hive.
  3. On the Hive service page, click the Configure tab.
  4. Modify configurations.
    1. Enter hive.execution.engine in the search box and click Search.
    2. Set the hive.execution.engine parameter to tez.
  5. Save the configurations.
    1. Click Save in the upper-right corner of the Hive service page.
    2. In the Confirm Changes dialog box, specify Description and click OK.
  6. Restart HiveServer2.
    1. On the Hive service page, choose Actions > Restart HiveServer2 in the upper-right corner.
    2. In the Cluster Activities dialog box, specify Description and click OK.
    3. In the Confirm message, click OK.

Access the web UI of Tez

You can click the URL of Tez on the Public Connect Strings page to access the web UI of Tez.