Installation
Running JanusGraph inside a Docker container
For virtualization and easy access, JanusGraph provides a Docker image. Docker makes it easier to run servers and clients on a single machine without dealing with multiple installations. For instructions on installing and using Docker, please refer to the docker guide. Let's try running a simple JanusGraph instance in Docker:
$ docker run -it -p 8182:8182 janusgraph/janusgraph
8182 available for us to see.
The server may need a few seconds to start up so be patient and wait for the corresponding log messages to appear.
Example log
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/opt/janusgraph/lib/slf4j-log4j12-1.7.12.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/opt/janusgraph/lib/logback-classic-1.1.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]
0 [main] INFO com.jcabi.manifests.Manifests - 110 attributes loaded from 283 stream(s) in 130ms, 110 saved, 3770 ignored: ["Agent-Class", "Ant-Version", "Archiver-Version", "Automatic-Module-Name", "Bnd-LastModified", "Boot-Class-Path", "Branch", "Build-Date", "Build-Host", "Build-Id", "Build-Java-Version", "Build-Jdk", "Build-Job", "Build-Number", "Build-Timestamp", "Build-Version", "Built-At", "Built-By", "Built-Date", "Built-OS", "Built-On", "Built-Status", "Bundle-ActivationPolicy", "Bundle-Activator", "Bundle-BuddyPolicy", "Bundle-Category", "Bundle-ClassPath", "Bundle-ContactAddress", "Bundle-Description", "Bundle-DocURL", "Bundle-License", "Bundle-ManifestVersion", "Bundle-Name", "Bundle-NativeCode", "Bundle-RequiredExecutionEnvironment", "Bundle-SymbolicName", "Bundle-Vendor", "Bundle-Version", "Can-Redefine-Classes", "Change", "Class-Path", "Created-By", "DSTAMP", "DynamicImport-Package", "Eclipse-BuddyPolicy", "Eclipse-ExtensibleAPI", "Embed-Dependency", "Embed-Transitive", "Export-Package", "Extension-Name", "Extension-name", "Fragment-Host", "Gradle-Version", "Gremlin-Lib-Paths", "Gremlin-Plugin-Dependencies", "Gremlin-Plugin-Paths", "Ignore-Package", "Implementation-Build", "Implementation-Build-Date", "Implementation-Title", "Implementation-URL", "Implementation-Vendor", "Implementation-Vendor-Id", "Implementation-Version", "Import-Package", "Include-Resource", "JCabi-Build", "JCabi-Date", "JCabi-Version", "Java-Vendor", "Java-Version", "Main-Class", "Manifest-Version", "Maven-Version", "Module-Email", "Module-Origin", "Module-Owner", "Module-Source", "Originally-Created-By", "Os-Arch", "Os-Name", "Os-Version", "Package", "Premain-Class", "Private-Package", "Provide-Capability", "Require-Bundle", "Require-Capability", "Scm-Connection", "Scm-Revision", "Scm-Url", "Specification-Title", "Specification-Vendor", "Specification-Version", "TODAY", "TSTAMP", "Time-Zone-Database-Version", "Tool", "X-Compile-Elasticsearch-Snapshot", "X-Compile-Elasticsearch-Version", "X-Compile-Lucene-Version", "X-Compile-Source-JDK", "X-Compile-Target-JDK", "hash", "implementation-version", "mode", "package", "service", "url", "version"]
1 [main] INFO org.apache.tinkerpop.gremlin.server.GremlinServer - 3.4.1
\,,,/
(o o)
-----oOOo-(3)-oOOo-----
100 [main] INFO org.apache.tinkerpop.gremlin.server.GremlinServer - Configuring Gremlin Server from /etc/opt/janusgraph/gremlin-server.yaml
...
...
3965 [gremlin-server-boss-1] INFO org.apache.tinkerpop.gremlin.server.GremlinServer - Gremlin Server configured with worker thread pool of 1, gremlin pool of 8 and boss thread pool of 1.
3965 [gremlin-server-boss-1] INFO org.apache.tinkerpop.gremlin.server.GremlinServer - Channel started at port 8182.
We can now start a Gremlin Console on our local device and try to connect to the new server:
$ bin/gremlin.sh
\,,,/
(o o)
-----oOOo-(3)-oOOo-----
gremlin> :remote connect tinkerpop.server conf/remote.yaml
==>Configured localhost/127.0.0.1:8182
Conveniently, it's also possible to run both the server and the client within separate Docker containers. We therefore instantiate a container for the server:
$ docker run --name janusgraph-default janusgraph/janusgraph:latest
$ docker run --rm --link janusgraph-default:janusgraph -e GREMLIN_REMOTE_HOSTS=janusgraph \
-it janusgraph/janusgraph:latest ./bin/gremlin.sh
\,,,/
(o o)
-----oOOo-(3)-oOOo-----
gremlin> :remote connect tinkerpop.server conf/remote.yaml
==>Configured janusgraph/172.17.0.2:8182
Local Installation
In order to run JanusGraph, Java 8 SE is required.
Make sure the $JAVA_HOME environment variable points to the correct location where either JRE or JDK is installed.
JanusGraph can be downloaded as a .zip archive from the Releases section of the project repository.
$ unzip janusgraph-0.4.1-hadoop2.zip
Archive: janusgraph-0.4.1-hadoop2.zip
creating: janusgraph-0.4.1-hadoop2/
...
Once you have unzipped the downloaded archive, you are ready to go.
Running the Gremlin Console
The Gremlin Console is an interactive shell that gives you access to the data managed by JanusGraph.
You can reach it by running the gremlin.sh script which is located in the project's bin directory.
$ cd janusgraph-0.4.1-hadoop2
$ bin/gremlin.sh
\,,,/
(o o)
-----oOOo-(3)-oOOo-----
09:12:24 INFO org.apache.tinkerpop.gremlin.hadoop.structure.HadoopGraph - HADOOP_GREMLIN_LIBS is set to: /usr/local/janusgraph/lib
plugin activated: tinkerpop.hadoop
plugin activated: janusgraph.imports
gremlin>
The Gremlin Console interprets commands using Apache Groovy, which is a superset of Java. Gremlin-Groovy extends Groovy by providing a set of methods for basic and advanced graph traversal funcionality. For a deeper dive into Gremlin language's features, please refer to our introduction to Gremlin.
Running the Gremlin Server
In most real-world use cases, queries to a database will not be run from the exact same server the data is stored on. Instead, there will be some sort of client-server hierarchy in which the server runs the database and handles requests while multiple clients create these requests and thereby read and write entries within the database independently of one another. This behavior can also be achieved with JanusGraph.
In order to start a server on your local machine, simply run the gremlin-server.sh script instead of the gremlin.sh script.
You can optionally pass a configuration file as a parameter.
The default configuration is located at conf/gremlin-server/gremlin-server.yaml.
$ ./bin/gremlin-server.sh start
$ ./bin/gremlin-server.sh /conf/gremlin-server/[...].yaml
Info
By default, JanusGraph will try to use a CQL-compatible storage backend. To use another backend, the following line within the earlier mentioned default configuration must be altered:
graphs: {
graph: conf/gremlin-server/janusgraph-cql-es-server.properties
}
inmemory backend provided by conf/janusgraph-inmemory.properties is the easiest option to use.
For further information about storage backends, visit the corresponding section of the documentation.
You are also encouraged to look into janusgraph.sh, which by defaults starts a more sophisticated server than gremlin-server.sh.
Further documentation on server configuration can be found in the JanusGraph Server section.
A Gremlin server is now running on your local machine and waiting for clients to connect on the default port 8182.
To instantiate a client -- as done before -- run the gremlin.sh script.
Again, a local Gremlin Console will show up.
This time, instead of using it locally, we will connect the Gremlin Console to a remote server and redirect all of it's queries to this server.
This is done by using the :remote command:
gremlin> :remote connect tinkerpop.server conf/remote.yaml
==>Configured localhost/127.0.0.1:8182
conf/remote.yaml file.
Warning
The above command only establishes the connection to the server.
It does not forward the following commands to the server by default!
As a result, further commands will still be executed locally unless preceeded by :>.
To forward every command to the remote server, use the :remote console command.
Further documentation can be found in the TinkerPop reference docs