Repository: tinkerpop Updated Branches: refs/heads/TINKERPOP-939 [created] 622065386
Added docs for Neo4j HA configuration. Project: http://git-wip-us.apache.org/repos/asf/tinkerpop/repo Commit: http://git-wip-us.apache.org/repos/asf/tinkerpop/commit/62206538 Tree: http://git-wip-us.apache.org/repos/asf/tinkerpop/tree/62206538 Diff: http://git-wip-us.apache.org/repos/asf/tinkerpop/diff/62206538 Branch: refs/heads/TINKERPOP-939 Commit: 6220653868fc0c00a397456f9b7cceae82c3cb4a Parents: 84f2d63 Author: Stephen Mallette <sp...@genoprime.com> Authored: Thu Jun 16 11:54:02 2016 -0400 Committer: Stephen Mallette <sp...@genoprime.com> Committed: Thu Jun 16 11:54:02 2016 -0400 ---------------------------------------------------------------------- .../reference/implementations-neo4j.asciidoc | 74 ++++++++++++++++++++ 1 file changed, 74 insertions(+) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/tinkerpop/blob/62206538/docs/src/reference/implementations-neo4j.asciidoc ---------------------------------------------------------------------- diff --git a/docs/src/reference/implementations-neo4j.asciidoc b/docs/src/reference/implementations-neo4j.asciidoc index 2e47180..998eb74 100644 --- a/docs/src/reference/implementations-neo4j.asciidoc +++ b/docs/src/reference/implementations-neo4j.asciidoc @@ -259,3 +259,77 @@ gremlin.neo4j.directory=/tmp/neo4j gremlin.neo4j.conf.node_auto_indexing=true gremlin.neo4j.conf.relationship_auto_indexing=true ---- + +High Availability Configuration +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +TinkerPop supports running Neo4j with its fault tolerant master-slave replication configuration, referred to as its +link:http://neo4j.com/docs/operations-manual/current/#_neo4j_cluster_install[High Availability (HA) cluster]. From the +TinkerPop perspective, configuring for HA is not that different than configuring for embedded mode as shown above. The +main difference is the usage of HA configuration options that enable the cluster. Once connected to a cluster, usage +from the TinkerPop perspective is largely the same. + +In configuring for HA the most important thing to realize is that all Neo4j HA settings are simply passed through the +TinkerPop configuration settings given to the `GraphFactory.open()` or `Neo4j.open()` methods. For example, to +provide the all-important `ha.server_id` configuration option through TinkerPop, simply prefix that key with the +TinkerPop Neo4j key of `gremlin.neo4j.conf`. + +The following properties demonstrates one of the three configuration files required to setup a simple three node HA +cluster on the same machine instance: + +[source,properties] +---- +gremlin.graph=org.apache.tinkerpop.gremlin.neo4j.structure.Neo4jGraph +gremlin.neo4j.directory=/tmp/neo4j.server1 +gremlin.neo4j.conf.ha.server_id=1 +gremlin.neo4j.conf.ha.initial_hosts=localhost:5001\,localhost:5002\,localhost:5003 +gremlin.neo4j.conf.ha.cluster_server=localhost:5001 +gremlin.neo4j.conf.ha.server=localhost:6001 +---- + +Assuming the intent is to configure this cluster completely within TinkerPop (perhaps within three separate Gremlin +Server instances), the other two configuration files will be quite similar. The second will be: + +[source,properties] +---- +gremlin.graph=org.apache.tinkerpop.gremlin.neo4j.structure.Neo4jGraph +gremlin.neo4j.directory=/tmp/neo4j.server2 +gremlin.neo4j.conf.ha.server_id=2 +gremlin.neo4j.conf.ha.initial_hosts=localhost:5001\,localhost:5002\,localhost:5003 +gremlin.neo4j.conf.ha.cluster_server=localhost:5002 +gremlin.neo4j.conf.ha.server=localhost:6002 +---- + +and the third will be: + +[source,properties] +---- +gremlin.graph=org.apache.tinkerpop.gremlin.neo4j.structure.Neo4jGraph +gremlin.neo4j.directory=/tmp/neo4j.server3 +gremlin.neo4j.conf.ha.server_id=3 +gremlin.neo4j.conf.ha.initial_hosts=localhost:5001\,localhost:5002\,localhost:5003 +gremlin.neo4j.conf.ha.cluster_server=localhost:5003 +gremlin.neo4j.conf.ha.server=localhost:6003 +---- + +IMPORTANT: The backslashes in the values provided to `gremlin.neo4j.conf.ha.initial_hosts` prevent that configuration +setting as being interpreted as a `List`. + +Create three separate Gremlin Server configuration files and point each at one of these Neo4j files. Since these Gremlin +Server instances will be running on the same machine, ensure that each Gremlin Server instance has a unique `port` +setting in that Gremlin Server configuration file. Start each Gremlin Server instance to bring the HA cluster online. + +NOTE: `Neo4jGraph` instances will block until all nodes join the cluster. + +Neither Gremlin Server nor Neo4j will share transactions across the cluster. Be sure to either use Gremlin Server +managed transactions or, if using a session without that option, ensure that all requests are being routed to the +same server. + +This example discussed use of Gremlin Server to demonstrate the HA configuration, but it is also easy to setup with +three Gremlin Console instances. Simply start three Gremlin Console instances and use `GraphFactory` to read those +configuration files to form the cluster. Furthermore, keep in mind that it is possible to have a Gremlin Console join +a cluster handled by two Gremlin Servers or Neo4j Enterprise. The only limits as to how the configuration can be +utilized are prescribed by Neo4j itself. Please refer to their +link:http://neo4j.com/docs/operations-manual/current/#ha-setup-tutorial[documentation] for more information on how +this feature works. +
