Azure Data Lake Storage

Azure Data Lake Storage

This guide describes how to configure Alluxio with Azure Data Lake Storage Gen1 as the under storage system.

Prerequisites

The Alluxio binaries must be on your machine. You can either compile the binaries from Alluxio source code, or download the precompiled binaries directly.

In preparation for using Azure Data Lake storage with Alluxio, create a new Data Lake storage in your Azure account or use an existing Data Lake storage. You should also note the directory you want to use, either by creating a new directory, or using an existing one. You also need to set up Service-to-service authentication for your storage account. For the purposes of this guide, the Azure storage account name is called <AZURE_ACCOUNT> and the directory in that storage account is called <AZURE_DIRECTORY>. For more information about Azure storage account, Please see here.

Basic Setup

Root Mount

To use Azure Data Lake Storage as the UFS of Alluxio root mount point, you need to configure Alluxio to use under storage systems by modifying conf/alluxio-site.properties. If it does not exist, create the configuration file from the template.

$ cp conf/alluxio-site.properties.template conf/alluxio-site.properties

Specify the underfs address by modifying conf/alluxio-site.properties to include:

alluxio.master.mount.table.root.ufs=adl://<AZURE_ACCOUNT>.azuredatalakestore.net/<AZURE_DIRECTORY>/

Specify the application ID, authentication key and tenant ID for the Azure AD application used for the Azure account of the root mount point by adding the following properties in conf/alluxio-site.properties:

For instructions on how to retrieve the application ID and authentication key (also called the client secret) for your application, see Get application ID and authentication key.
For instructions on how to retrieve the tenant ID, see Get tenant ID.

alluxio.master.mount.table.root.option.fs.adl.account.<AZURE_ACCOUNT>.oauth2.client.id=<APPLICATION_ID>
alluxio.master.mount.table.root.option.fs.adl.account.<AZURE_ACCOUNT>.oauth2.credential=<AUTHENTICATION_KEY>
alluxio.master.mount.table.root.option.fs.adl.account.<AZURE_ACCOUNT>.oauth2.refresh.url=https://login.microsoftonline.com/<TENANT_ID>/oauth2/token

Nested Mount

An Azure Data Lake store location can be mounted at a nested directory in the Alluxio namespace to have unified access to multiple under storage systems. Alluxio’s Command Line Interface can be used for this purpose.

$ ./bin/alluxio fs mount \
  --option fs.adl.account.<AZURE_ACCOUNT>.oauth2.client.id=<APPLICATION_ID>
  --option fs.adl.account.<AZURE_ACCOUNT>.oauth2.credential=<AUTHENTICATION_KEY>
  --option fs.adl.account.<AZURE_ACCOUNT>.oauth2.refresh.url=https://login.microsoftonline.com/<TENANT_ID>/oauth2/token
  /mnt/adls adl://<AZURE_ACCOUNT>.azuredatalakestore.net/<AZURE_DIRECTORY>/

After these changes, Alluxio should be configured to work with Azure Data Lake storage as its under storage system, and you can run Alluxio locally with it.

Running Alluxio Locally with Data Lake Storage

Start up Alluxio locally to see that everything works.

./bin/alluxio format
./bin/alluxio-start.sh local

This should start an Alluxio master and an Alluxio worker. You can see the master UI at http://localhost:19999.

Run a simple example program:

./bin/alluxio runTests

Visit your directory <AZURE_DIRECTORY> to verify the files and directories created by Alluxio exist. For this test, you should see files named like:

<AZURE_DIRECTORY>/default_tests_files/BASIC_CACHE_PROMOTE_CACHE_THROUGH

To stop Alluxio, you can run:

./bin/alluxio-stop.sh local