Experiment with distributed upload locks

[Acconut]

Currently we only support memory and file locks, whose reach is limited to a single machine. If you want to properly scale horizontally, a distributed lock is needed, such as Redis, Consul, etcd etc.

@Murderlon proposed the use of https://github.com/matryer/vice, which wraps multiple messaging services into a single interface. Maybe that is helpful. More infos at https://medium.com/@matryer/introducing-vice-go-channels-across-many-machines-bcac1147d7e2.

[Murderlon]

After a small attempt myself, I don't think vice is perfect for this use case. Redis can be used as a message broken but it will only be in-memory and no guaranteed arrival confirmation. Meaning, if uploader A sends a lock message over Redis and uploader B isn't listening at the time, it's stuck forever. The other message queue technologies supported by vice likely don't have this problem

In the case of Redis, they designed an algorithm specifically for this called RedLock. Which I'm going to try soon.

[Acconut]

Thanks for the feedback! RedLock does look interesting, so let me know if you have some more insights.

[Acconut]

Thanks, NATS does also look interesting on its own.

[Acconut]

Interesting links, thank you. Let us know if you are interested in trying out NATS for tusd's locks and we can assist you :)

[Acconut]

I am interested because I want to use it with Pocketbase, so that uploads can be resilient

Great idea!

The upload aspect is also handled there but I don’t know if the tusd protocol is conflating things tbh.

Not sure what you mean by this. Do you want to handle file uploads directly via NATS? If so, the tusd might not be necessary for you.

[Acconut]

Interesting approach, but this issue talks about a different use case for distributed systems. We want to look into how a distributed system can be used to lock upload resources and ensure exclusive access in the presence of multiple requests (see https://github.com/tus/tusd/blob/main/docs/locks.md). What you are proposing is something different AFAIU

[cawfeecoder]

Why wouldn't you do a lease and lock on ETCD?

[Acconut]

Tusd would offer multiple implementation for the user to choose from. An etcd-based approach using leases is also a possibility.