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valkey-io / valkey

A flexible distributed key-value datastore that supports both caching and beyond caching workloads.
https://valkey.io
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Don't use master/slave terminology (non-breaking changes only) #36

Open zuiderkwast opened 5 months ago

zuiderkwast commented 5 months ago

Primary and replica are the preferred terms.

The current situation is master/replica, with slave kept as an alias of replica. Some commands like ROLE still returns "master" and "slave".

So far "master" was accepted, so there aren't yet any aliases for "master". Let's introduce aliases and deprecate master.

  1. Add aliases for master (not a breaking change)
  2. Delete master and slave terminology (breaking change) EDIT: After feedback, we've decided to skip the breaking changes. We can only that as a client opt-in. See #751.

Occurrences of "master" where we can add "primary" and make "master" an alias:

Note: This issue was edited to not include any breaking changes. The initial suggestion included breaking changes, but this was not appreciated by the users. Thus, the downvotes.

GaryPWhite commented 5 months ago

Hi! Would this be a decent "first issue" for a techie who's interested in getting more involved with the alt/redis ecosystem? I'd be happy to use this as a way to get more familiar with the repo :)

zuiderkwast commented 5 months ago

@GaryPWhite Yes, that's great, but first we need to analyze and decide exactly what we need to do and in which steps. There are implications like Redis compatibility to consider.

zuiderkwast commented 5 months ago

@GaryPWhite Actually I think you can start with the non-breaking changes of simply adding PRIMARY aliases (or rather make MASTER an alias of PRIMARY) for these:

Look into how SLAVE is already an alias of REPLICA in these commands.

hwware commented 5 months ago

Agree with master as an alias of primary. But suggest to hold the master and slave name, maybe they will remove in future version

zuiderkwast commented 5 months ago

Yes, the breaking change is a "major decision". We should analyze the implications a bit more too. There may be reasons to be compatible with other forks and implementations so we should also keep on eye on them.

We may even consider some possibility for conditional compilation or similar.

PingXie commented 5 months ago

I would vote for "primary" and "replica".

As for changes, I now think more and more that we need a "compat" knob. It can be either compile time or runtime (via config).

We could also consider a staged change:

  1. Anything non-user facing, i.e., comments, function/variable names, etc

  2. Aliasing input to support both terminologies (but also under the "compat" switch)

  3. Changing output. Aliasing would not work in this case. We will default to the new terminology but it can be overridden by the user, again either compile time or runtime (pending decision)

zuiderkwast commented 5 months ago

Yes, 1 and 2 can be done immediately IMO, but in two separate PRs.

stockholmux commented 5 months ago

If there is a compat knob, it would be good to have a pre-determined sequence of deprecation.

E.g. version n introduce knob and optional new terminology, version n+1 new terminology becomes default, old terminology is deprecated, version n+2 remove old terminology.

Otherwise these things just linger. Pull off the bandaid, as they say.

PingXie commented 5 months ago

Pull off the bandaid, as they say

Yes we should do it at some point but I think the timing of it falls in another major decision and we need to give our users ample time to adjust. As much as I am personally in strong favor of ripping this bandaid off asap I also understand that the success of this project is very much dependent on "continuity". It takes time to turn this huge ship around.

stockholmux commented 5 months ago

3 major version would be enough transition time, I'd assume.

But mainly I'm just advocating have a set plan before changes happen so it doesn't languish for an undetermined amount of time.

PingXie commented 5 months ago

I'm just advocating have a set plan before changes happen so it doesn't languish for an undetermined amount of time.

Timing aside, I think one option, as you suggested too, is to just remove this compat knob and we are done. I have yet to think of other options because as far as output is concerned, it is a binary decision. So the plan in my opinion is more about deliberating a timeline with the help of the community, than an engineering plan to help with a smooth transition. In other words, I think https://github.com/placeholderkv/placeholderkv/issues/36#issuecomment-2020632035 is the best we can do. Curious to hear other folks' thoughts.

hpatro commented 5 months ago

de-crapify 😂

DarrenJiang13 commented 5 months ago

Maybe we need to consider some compatibility to SDKs like jedis.

Like "cluster nodes", it may return with "master" field and might be used by some SDKs.

zuiderkwast commented 5 months ago

@alonohana627 May I ask why you down-voted this? Just curious. If it's about compatibility, I'd like to hear it so we can make a better decision.

singlyfy commented 5 months ago

@alonohana627 May I ask why you down-voted this? Just curious. If it's about compatibility, I'd like to hear it so we can make a better decision.

all his (recently) created github repositories are using "master" for branch naming, so I think it is personal preference in this case

alonohana627 commented 5 months ago

@singlyfy @zuiderkwast sry for downvote!!! I don't have an opinion, when I create a repo I don't consider the main's repo name. It was a missclick. I remove the downvote.

I want to contribute but I'm new, I'm not sure if upvote/downvote this suggestion because I sincerely don't understand it. I hope you won't think I tried to troll or anything, sorry for the inconvenient.

Dom4n commented 5 months ago

I have down-voted only because I don't encourage making breaking changes, aliases are totally fine. But please do not force name change by removing old naming conventions.

zuiderkwast commented 5 months ago

@Dom4n It is a very valid concern. I think backward compatibility is very important, especially in this kind of project which has been mostly feature-complete since many years. Let's think about it a bit more.

zuiderkwast commented 5 months ago

@GaryPWhite Are you still interesting in helping out with the non-breaking changes?

We will not do any of the breaking changes at this point.

GaryPWhite commented 4 months ago

absolutely interested -- sorry for the delay. Felt like a lot happened at once -- I'll start taking a look!

GaryPWhite commented 4 months ago

@zuiderkwast , I have taken a look and don't really have time to dig into this and do it right. Other folks should feel free to pick this up :) sorry for whiplast!

robd003 commented 2 months ago

There is zero logical reason to make a breaking name change like this. It's just going to cause issues with 3rd party tools.

Nothing of value will be gained by doing this.

madolson commented 2 months ago

There is zero logical reason to make a breaking name change like this

We're only making the non-breaking changes. Anything part of the API (the command names) or API responses will remain the same.