Thoth's additions to JanusGraph

The content of this directory should land at /opt/janusgraph-0.3.1-hadoop2/, it contains the Thoth specific configuration of JanusGraph.

Running JanusGraph instance locally

First, make sure you have buildah and podman installed:

dnf install -y podman buildah

Note, currently all the commands have to be run as root (prepend "sudo).

You can run JanusGraph locally on your workmachine if you would like to experiment with schema, graph queries or graph-related stuff in Thoth. To do so, you need to first build a JanusGraph container. There is provided a handy utility local.sh which helps you to manage a local JanusGraph instance.

./local.sh build

The command above will produce a container image with JanusGraph without any schema and indexes being created. To initialize JanusGraph with schema and indexes, run the following command after the build command:

./local.sh init

With this command you will have an initialized local JanusGraph instance which you can run using the run command:

./local.sh run

During the init command, there is used schema and indexes from the local Git repository so if you make any changes to them, they will be propagated to the built JanusGraph instance (handy for local tests and development). If you would like to rebuild the container with new changes made to the schema, you can simply do by repeating the init command (note the un-initialized JanusGraph instance is kept untouched).

To simply run all of the above to have a coffee meanwhile, just run:

./local.sh all

To clean your local development environment, just run:

./local.sh clean

See the following command for more help:

./local.sh help

The commands discussed above will run the JanusGraph on your machine, which will be accessible on 8182 port (default for JanusGraph). To interact with this instance, you can export JANUSGRAPH_SERVICE_HOST=localhost and all the libraries and CLIs in Thoth will automatically talk to this instance. See Thoth's Developer Guide for more info.

Connecting to a remote instance using Gremlin shell

First, download JanusGraph release which provides gremlin shell:

./local.sh download

Adjust entry in hosts so that it points to an instance you would like to talk to:

vim janusgraph-*-hadoop2/conf/remote.yaml
# Adjust "hosts", e.g. from:
#   hosts: [localhost]
# to:
#   hosts: [janusgraph.test.thoth-station.ninja]
# sed -i s/localhost/janusgraph.test.thoth-station.ninja/ janusgraph-*-hadoop2/conf/remote.yaml

Run Gremlin shell:

./janusgraph-0.3.1-hadoop2/bin/gremlin.sh

And execute following commands to connect to a remote instance:

:remote connect tinkerpop.server conf/remote.yaml session
:remote console

To profile a query:

g.V().count().profile()

Troubleshooting local instance

Q: I'm getting an error message that the JanusGraph instance has too many files opened.

Place the following configuration into your /etc/security/limits.conf:

* soft nofile 4096
* hard nofile 4096

And verify the new configuration is applied:

$  ulimit -Sn