AWS Documentation » Amazon EMR Documentation » Amazon EMR Release Guide » Presto » Considerations with Presto on Amazon EMR

Considerations with Presto on Amazon EMR

Consider the following differences and limitations when you run Presto on Amazon EMR.

Some Presto Deployment Properties not Configurable

Depending on the version of Amazon EMR that you use, some Presto deployment configurations may not be available. For more information about these properties, see Deploying Presto in Presto Documentation. The following table shows the configuration status for Presto properties files.

File	Configurable
log.properties	Configurable in all Amazon EMR release versions. Use the presto-log configuration classification in Amazon EMR release version 4.0.0 and later.
config.properties	Configurable in all Amazon EMR release versions. Use the presto-config configuration classification in Amazon EMR release version 4.0.0 and later.
hive.properties	Configurable in Amazon EMR release version 4.1.0 and later. Use the presto-connector-hive configuration classification.
node.properties	Configurable in Amazon EMR release version 5.6.0 and later. Use the presto-node configuration classification.
jvm.config	Not configurable.

EMRFS and PrestoS3FileSystem Configuration

With Amazon EMR release version 5.12.0 and later, Presto can use EMRFS, and this is the default configuration. For more information, see Using EMR File System (EMRFS) in the Amazon EMR Management Guide. With earlier release versions, PrestoS3FileSystem is the only option.

Using EMRFS has benefits. You can use a security configuration to set up encryption for EMRFS data in Amazon S3. You can also use IAM roles for EMRFS requests to Amazon S3. For more information, see Understanding Encryption Options and Configure IAM Roles for EMRFS Requests to Amazon S3 in the Amazon EMR Management Guide.

Note

A configuration issue can cause Presto errors when querying underlying data in Amazon S3 with Amazon EMR release version 5.12.0. This is because Presto fails to pick up configuration classification values from emrfs-site.xml. As a workaround, create an emrfs subdirectory under usr/lib/presto/plugins/hive-hadoop2/, create a symlink in usr/lib/presto/plugins/hive-hadoop2/emrfs to the existing /usr/share/aws/emr/emrfs/conf/emrfs-site.xml file, and then restart the presto-server process (sudo presto-server stop followed by sudo presto-server start).

You can override the EMRFS default and use the PrestoS3FileSystem instead. To do this, use the presto-connector-hive configuration classification to set hive.s3-file-system-type to PRESTO as shown in the following example. For more information, see Configuring Applications.

[
   {
      "Classification": "presto-connector-hive",
      "Properties": {
         "hive.s3-file-system-type": "PRESTO"
      }
   }
]

If you use PrestoS3FileSystem, use the presto-connector-hive configuration classification to configure PrestoS3FileSystem properties. For more information about available properties, see Amazon S3 Configuration in the Hive Connector section of Presto documentation. These settings do not apply to EMRFS.

Default Setting for End User Impersonation

By default, Amazon EMR version 5.12.0 and later enables end user impersonation for accessing HDFS. For more information, see End User Impersonation in the Presto documentation. You can change this setting using the presto-config configuration classification to set the hive.hdfs.impersonation.enabled property to false.

Default Port for Presto Web Interface

By default, Amazon EMR configures the Presto web interface on the Presto coordinator to use port 8889. You can change this using the presto-config configuration classification to set the http-server.http.port property. For more information, see Config Properties in the Deploying Presto section of Presto Documentation.

Issue with Hive Bucket Execution in Some Releases

Presto version 152.3 has an issue with Hive bucket execution that causes significantly slower Presto query performance in some circumstances. This version is included with Amazon EMR release versions 5.0.3, 5.1.0, and 5.2.0. To mitigate this issue, use the presto-connector-hive configuration classification to set the hive.bucket-execution property to false as shown in the following example.

[
   {
      "Classification": "presto-connector-hive",
      "Properties": {
         "hive.bucket-execution": "false"
      }
   }
]