Noteworthy at Compose - Working with hosted JanusGraph

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This is your weekly summary of Compose news for those changes and updates which can make your life easier. In this edition, we look at how Compose JanusGraph makes creating graphs easier and we look at the past week's Compose Articles.

JanusGraph Tips

A lot of users have had a look at JanusGraph on Compose, the Scylla-backed graph database, and they've been having a great time with it. But some people have been caught out by how we host the database and how that affects some of the JanusGraph commands.

TL;DR: Never use JanusGraphFactory, always use ConfiguredGraphFactory.

When you create a graph in a locally installed JanusGraph, you use JanusGraphFacory. It uses the local filesystem to store information about how that graph is configured, no matter what backend database it is stored on. When hosting JanusGraph imaged containers, that kind of local storage is not really safe to use; it can be erased easily, even just by restarting the database and its hard to backup. With that in mind, the JanusGraph engineering team at IBM Compose created a new way to store that information - in the backend database and in its own graph.

Effectively, JanusGraph on Compose is hard wired to connect to the Scylla backend. This allows a new Graph Factory, ConfiguredGraphFactory to use the backend to store all the graph metadata in a graph dedicated to configuration information. That means that when you create a graph with ConfiguredGraphFactory there's no writing to local file systems and the metadata is backed up with the rest of the data making it much easier to manage.

An added bonus is that where JanusGraphFactory accepts all sorts of configuration settings as parameters, all that's needed for a ConfiguredGraphFactory is the name of your graph as a parameter.

One note though, when you do come to delete a graph from the ConfiguredGraphFactory, with the current JanusGraph implementation, there's a couple of steps to removing the graph. Consult the documentation for details on how to do this.

Compose Articles

In the last week, Compose Articles showed the latest functionality in the Bach command line tool, and rounded up the database and developer news from around the internet:

That's the week in Noteworthy at Compose and now we're ready for another week!


Read more articles about Compose databases - use our Curated Collections Guide for articles on each database type. If you have any feedback about this or any other Compose article, drop the Compose Articles team a line at articles@compose.com. We're happy to hear from you.

Dj Walker-Morgan
Dj Walker-Morgan was Compose's resident Content Curator, and has been both a developer and writer since Apples came in II flavors and Commodores had Pets. Love this article? Head over to Dj Walker-Morgan’s author page to keep reading.

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