FoundationDB

Key "\xFF/coordinators" changed behavior since earlier versions


(Christophe Chevalier) #1

Looking through all my failing tests, I noticed that before the key '\xFF/coordinators' would return a value that would start with 'local:...'. Now it returns a long numerical string which match the one in my fdb.cluster file.

I read this key to expose the list of coordinators via an API that return an FdbClusterFile object with properties exposing the content of this key.

I suspect that the local: prefix was a thing in earlier versions that has been changed a long time ago. Can I safely fix the test to no longer check for this?

For my curiosity, what was “local:” about, and why was it changed?


(David Scherer) #2

I think that when you saw “local:” in there before, it was in your cluster file too. Clusters have a “description” that I guess on installation used to default to “local” and now is randomly generated. Presumably this is because we found people never changed it and production clusters were still named “local” (and hence identically).

If you change the description in the CLI you should see it in the FF keyspace as well:

fdb> coordinators description=hello
Coordination state changed
fdb> option on READ_SYSTEM_KEYS
Option enabled for all transactions
fdb> get \xff/coordinators
`\xff/coordinators' is `hello:2Lcrk0LFZg5oZM1XipUZgW7KlpaE5Pma@127.0.0.1:4500'

(Christophe Chevalier) #3

OK so this was a relic of the past and this test was likely already failing for other people.