Ozone

    This guide describes how to configure Ozone as Alluxio’s under storage system. Ozone is a scalable, redundant, and distributed object store for Hadoop. Apart from scaling to billions of objects of varying sizes, Ozone can function effectively in containerized environments such as Kubernetes and YARN.

    To run an Alluxio cluster on a set of machines, you must deploy Alluxio binaries to each of these machines. You can either with the correct Hadoop version (recommended), or compile the binaries from Alluxio source code (for advanced users).

    In preparation for using Ozone with Alluxio, follow the to install a Ozone cluster, and follow the Volume Commands and to create volume and bucket for Ozone cluster.

    To configure Alluxio to use Ozone as under storage, you will need to modify the configuration file . If the file does not exist, create the configuration file from the template.

    1. alluxio.master.mount.table.root.ufs=o3fs://<OZONE_BUCKET>.<OZONE_VOLUME>/

    Start the Alluxio servers:

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

    Run a simple example program:

    1. $ ./bin/alluxio runTests

    Use the HDFS shell or Ozone shell to Visit your Ozone directory o3fs://<OZONE_BUCKET>.<OZONE_VOLUME>/<OZONE_DIRECTORY> to verify the files and directories created by Alluxio exist. For this test, you should see files named like <OZONE_BUCKET>.<OZONE_VOLUME>/<OZONE_DIRECTORY>/default_tests_files/BasicFile_CACHE_PROMOTE_MUST_CACHE.

    An Ozone location can be mounted at a nested directory in the Alluxio namespace to have unified access to multiple under storage systems. Alluxio’s can be used for this purpose. For example, the following command mounts a directory inside an Ozone bucket into Alluxio directory /ozone:

    1. $ ./bin/alluxio fs mount \
    2.   --option alluxio.underfs.hdfs.configuration=<DIR>/ozone-site.xml:<DIR>/core-site.xml \
    3.   /ozone o3fs://<OZONE_BUCKET>.<OZONE_VOLUME>/

    Possible and ozone-site.xml

    • core-site.xml
    1. <configuration>
    2.   <property>
    3.     <name>ozone.scm.names</name>
    4.     <value>localhost</value>
    5.   </property>
    6.   <property>
    7.     <name>scm.container.client.max.size</name>
    8.     <value>256</value>
    9.   </property>
    10.   <property>
    11.     <name>scm.container.client.idle.threshold</name>
    13.   <property>
    14.     <name>hdds.ratis.raft.client.rpc.request.timeout</name>
    15.     <value>60s</value>
    16.   </property>
    17.   <property>
    18.     <name>hdds.ratis.raft.client.async.outstanding-requests.max</name>
    19.     <value>32</value>
    20.   </property>
    21.   <property>
    22.     <name>hdds.ratis.raft.client.rpc.watch.request.timeout</name>
    23.     <value>180s</value>
    24.   </property>

    Make sure the related config file is on all servers nodes running Alluxio.

    Supported Ozone Versions

    Currently, the only tested Ozone version with Alluxio is .