Matt Lord

@rohit-nayak-ps and @shlomi-noach this removes all of the `stallHandler` related code: https://github.com/vitessio/vitess/pull/15797/commits/c666b1442b216413bd36f31926489cc0581af511 What we lose w/o it is the ability to perform out-of-band monitoring and errors. Meaning that the heartbeat...

Good news is that I can repeat the exact scenario and symptoms seen in production with the `Test case which demonstrates a more typical scenario that would be seen in...

@rohit-nayak-ps and @shlomi-noach OK, now that I'm able to repeat the exact issue seen in production (which kicked off this work) — I was missing a detail in that test...

> It says this in the description: > > > It's quite some time before that error surfaces when in this stalled state and when in the state leading up...

The vschema has a timestamp in it. But more importantly it's versioned in the topology server (e.g. etcd). I'm going to close this for now as it's not clear to...

Thanks! I think you are correct here and we’re not providing serializability (although we could via etcd key versions and revisions) so you could read an old version, update it,...

We should be able to enforce serializable changes across vtgates by leveraging the topo key version. For an example of where we're doing this today, look at the topo `Tablet`...

Thank you for the detailed issue @TonySparc ! There isn't currently a well defined behavior here — other than the code which will effectively not switch traffic if you have...

I also agree, FWIW. The fact that it uses a vtgate's healthcheck cache for this info poses a more serious issue (this had come up in an internal discussion previously)....

I think that the noted roadmap document answers this question. There's no hard commitment to anything, but it's definitely something that we've wanted to do. I'll let @deepthi comment as...