Persistence

[bketelsen]

Add (maybe optional?) persistence to Doozerd. Needs much thought and discussion.

[darkhelmet]

Even just a good way to dump/load everything. Would be useful to do backups (my use case is config data I'd rather not have to repopulate if something terrible happened, even with multiple nodes).

[cespare]

You could implement dump/load using the API now.

[mreiferson]

If you read through the commits from @4ad in https://github.com/4ad/doozerd he essentially comes to the conclusion that something like this doesn't belong (or need to be) in the core. I agree with this viewpoint.

I'm all for making it easy to backup (I happen to just use shell scripts with the command line client) but I think persistence as this issue intends should be handled separately (ie outside core doozerd).

[bernerdschaefer]

@mreiferson -- We at soundcloud are also doing out-of-band snapshot/journaling (with doozer-journal).

But this kind of solution -- and any alternative given the current core features -- has one major problem: sequence numbers are not preserved. If the cluster is restarted and rebuilt from an external source, all clients who attempt to use API calls which accept revisions will observe unexpected behavior.