Storing data in memory

[thdxr]

Is there a better way to do this than tmpfs and is it even worth doing this or are there better solutions when I don't care about the data being durable?

I see this: https://github.com/cockroachdb/cockroach/blob/master/storage/engine/in_mem.go

[thdxr]

Found it here:

cockroach/cli/flags.go

Line 130 in 016136e

"stores": `

[thdxr]

Unfortunately could not get it to work, any guidance would be appreciated

[tbg]

I'm assuming your node just sat there with a message like

connected to gossip but missing sentinel. Has the cluster been initialized? Use "cockroach init" to initialize.

We do support in-memory engines (as you noticed) but have been using them mostly for our unit tests. The problem in practice is that while you can start such a node, you can't bootstrap one (that would mean running cockroach init for that engine, but the engine gets destroyed when that process ends, so the subsequent start wouldn't behave any differently).

One way to get around it is bootstrapping with an on-disk store which can be removed once you have an otherwise in-mem cluster running, but honest support for this likely entails changes to how the initialization process is exposed through the command line tool.

So, short answer - what you're asking for is going to work at some point, but not yet. You can have a single-node in-mem instance for playing around with though; see the --dev flag.

[thdxr]

Thanks for that response, that's exactly the same conclusion that I arrived that.

[knz]

This is now possible thanks to #4027.
You can start a new node ready for replication with a memory-only data store using this command:

   cockroach start --stores=mem=12312312 

(or possibly with --join if joining an existing cluster) and this will not store the data persistently.