Check exact equality for worker state

[bnaul]

Per #3321 (comment), I agree it makes more sense to check for exact equality instead of relying on the hash (just in case 🙂).

I could see an argument for wrapping this tuple in a property so it can be reused, do we think that's preferable? I'd originally wanted to use identity for hash and eq but that has a bit too much going on IMO.

[bnaul]

cc @StephanErb

[mrocklin]

Thanks for picking this up @bnaul

This looks good to me. I'll merge after either a +1 from @StephanErb or a couple days.

[mrocklin]

My guess is that all of the test failures are intermittent. When we changed to spawn by default it unearthed a bunch of things. Squashing down a couple now.

[mrocklin]

Well, this one is interesting

    @gen_cluster(timeout=1000, client=True)
    def test_recompute_released_key(c, s, a, b):
        x = c.submit(inc, 100)
        result1 = yield x
        xkey = x.key
        del x
        import gc
    
        gc.collect()
        yield gen.moment
>       assert c.refcount[xkey] == 0
E       assert 1 == 0
E         -1
E         +0

[StephanErb]

Thanks for doing the follow up. As you have requested my review I have looked into the code a bit deeper. Please see my questions below.

[StephanErb]

I am wondering if using name and host is correct in all cases:

• name is optional and could be None
• host is not necessary unique as multiple workers could be running on the same machine

I am lacking necessary Dask context, so I am wondering why you have not picked address instead? It is used for indexing the WorkerState and the documentation says it is [t]his worker's unique key..

So I would assume, this here should work as expected:

def __hash__(self):
    return hash(self.address)	       

def __eq__(self, other):
    return type(self) == type(other) and self.address == other.address	

[bnaul]

I was just pulling items from the identity() dictionary, no personal reason to prefer one to the other. @TomAugspurger @mrocklin would you agree address makes more sense here?

[mrocklin]

Yes, address is probably the best thing to do in both cases.

…

On Sun, Feb 16, 2020 at 1:23 PM Brett Naul ***@***.***> wrote: ***@***.**** commented on this pull request. ------------------------------ In distributed/scheduler.py <#3483 (comment)>: > + return type(self) == type(other) and (self.name, self.host) == ( + other.name, + other.host, + ) I was just pulling items from the identity() function, no personal reason to prefer one to the other. @TomAugspurger <https://github.com/TomAugspurger> @mrocklin <https://github.com/mrocklin> would you agree address makes more sense here? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#3483?email_source=notifications&email_token=AACKZTHHWYYG6RFFP5E66PLRDGVFTA5CNFSM4KV3HXIKYY3PNVWWK3TUL52HS4DFWFIHK3DMKJSXC5LFON2FEZLWNFSXPKTDN5WW2ZLOORPWSZGOCVWHPWY#discussion_r379934436>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AACKZTAXOVLPZTZ4VHWKZBLRDGVFTANCNFSM4KV3HXIA> .

[bnaul]

thanks @StephanErb @mrocklin , updated w/ your suggestions