Lock with leases

[connor4312]

I was browsing through this client while working on a version for Node.js. I noticed that your locking is implemented on a straight k/v without using a lease. I suggest you consider using a lease for this, so that if something happens to the server or application which makes the lock, the resource isn't abandoned indefinitely. The downside is that it's possible that a lock is 'lost' while a process thinks it has it, but the set of situations in which that can occur and cause issues is a strict subset of the situations (only one I can think of: a partial network partition) in which the lock would otherwise be held indefinitely.

My implementation and little more reasoning is here, if you're interested: microsoft/etcd3#5

[kragniz]

The lock code is pretty dodgy, but it does use a lease https://github.com/kragniz/python-etcd3/blob/master/etcd3/locks.py#L57

It's mostly a stop-gap until etcd-io/etcd#7444 is released, at which point I'll switch to using that.

[connor4312]

Ah, great. Somehow I skimmed over that. Nevermind then! 😄