Authors:

Kanagaraj Mayilsamy

Sahina Bose

Shubhendu Tripathi

Feature pages are design documents that developers have created while collaborating on oVirt.

Most of them are outdated, but provide historical design context.

They are not user documentation and should not be treated as such.

Documentation is available here.

Gluster Geo Replication

Summary

This document describes the design for geo replication feature under gluster. For overview of this feature, refer Features/Gluster_Geo_Replication

Design

Geo-replication feature is designed to enable creation and maintenance of geo-replication sessions across clusters in GlusterFS. A geo-replication session can be setup between a GlusterFS managed source cluster and remote (destination) GlusterFS managed cluster.

Entity Description

Gluster Geo Replication Sessions

This entity stores the details of geo-replication sessions that are set up for gluster volumes

Column name	Type	description
session_id	UUID	Primary Key
master_volume_id	UUID	Id of the master gluster volume
session_key	String	Session key of the form `<masternode uuid>:<ssh url for slave volume>` For instance, `11ae7a03-e793-4270-8fc4-b42def8b3051:<ssh://192.168.122.14>::slave2`
slave_host_uuid	UUID	UUID of VDS in destination cluster used to create session
slave_host_name	String	Hostname of host in destination cluster used to create session
slave_volume_id	UUID	Volume id of destination volume
slave_volume_name	String	Volume name of destination volume
status	String	Status of geo-replication session. One of INITIALIZING, NOTSTARTED, ACTIVE, PASSIVE, STOPPED, PARTIAL_FAULTY, UNKNOWN, FAULTY (in GeoRepSessionStatus)

Gluster Geo Replication Session Details

This entity stores the details of the individual geo-replication sessions

Column name	Type	description
session_id	UUID	Ref to gluster_georep_session
master_brick_id	UUID	Ref to gluster_volume_bricks
slave_host_uuid	uuid	UUID of VDS host in destination cluster that brick is syncing to
slave_host_name	String	hostname of VDS host in destination cluster that brick is syncing to
status	String	status of brick connection. one of GeoRepSessionStatus
checkpoint_status	String
crawl_status	String
files_synced	bigint
files_pending	bigint
bytes_pending	bigint
deletes_pending	bigint
files_skipped	bigint

Gluster Geo Replication Session Configuration

This entity stores the configuration details of the individual geo-replication sessions

Column name	Type	description
config_key	String	Configuration key
config_value	String	Configuration value

REST APIs

The details of the REST for gluster geo-replication feature are as below -

Listing APIs

api/clusters/{id}/glustervolumes/{id}/georeplication-sessions - lists all the geo-replication sessions for a gluster volume

Output:

    <georeplication-sessions>
      <georeplication-session>
        <id>id</id>
        <host>Cluster Id</host>
        <slavevolume>Slave volume</slavevolume>
        <status>status</status>
      </georeplication-session>
      ...
    </georeplication-session>

api/clusters/{id}/glustervolumes/{id}/georeplication-sessions/{id} - lists the details of the individual geo-replication session

Output:

       <georeplication-session>
        <id>id</id>
        <host>Cluster Id</host>
        <slavevolume>Slave volume</slavevolume>
        <status>status</status>
        <session_details>
            <session_detail>
                 <brick>brick entity</brick>
                 <slaveNode>host</slaveNode>
                  <status>
                  <checkpoint_status></checkpoint_status>
                  <crawl_status></crawl_status>
                  <filesSkipped>Statistic</filesSkipped>
                  <filesPending>Statistic</filesPending>
                 <filesSynced>Statistic</filesSynced>
             <session_detail>
    ...
       </session_details>
      </georeplication-session>

api/clusters/{id}/glustervolumes/{id}/georeplication-sessions/{id}/options - lists all the configuration options for a geo-replication session

Output:

    <georeplication_options>
      <option>
        <id>Configuration Id</id>
        <key>Name of the configuration</key>
        <value>Value of the configuration</value>
      </option>
    </georeplication_options>

Actions Supported

POST api/clusters/{id}/glustervolumes/{id}/georeplication-sessions - creates a new geo-replication session for the cluster
- Parameter GeoRepSession type
api/clusters/{id}/glustervolumes/{id}/georeplication-sessions/{id}/start - starts the given geo-replication session
api/clusters/{id}/glustervolumes/{id}/georeplication-sessions/{id}/stop - stops the given geo-replication session
api/clusters/{id}/glustervolumes/{id}/georeplication-sessions/{id}/pause - pauses the given geo-replication session
api/clusters/{id}/glustervolumes/{id}/georeplication-sessions/{id}/resume - resumes the given geo-replication session

Gluster Geo Replication