Where is Circuit Breaker State stored?

[nareshkhatri81]

Hi Team,
i would like to know where Circuit Breaker state is stored.
is it stored in memory ?
is it possible to extend that and store it in external storage like redis ?
i have multiple containers running and if one container has tried calling service and it has tripped the circuit then i don't want other containers to call the service again which is tripped already by one container till circuit is opened again ?

Thanks,
Naresh Khatri

[reisenberger]

Hi @nareshkhatri81 . Thank you for your interest in Polly! CircuitState is stored in memory.

See #215 for discussion of external storage for Circuit Breaker State - let us know what you think!

One issue that has concerned me, with just saving the circuit state in eg Redis, is that it could lead to the "single bad node poisons other good nodes" problem discussed here, if the problem is in fact with the upstream node rather than the downstream system.

If that does occur - if the problem is in fact only with that single upstream node, but the shared storage 'applies' the problem also to the sibling upstream nodes - this effectively writes off the value of having the other horizontally-scaled nodes. Thus, discussion for implementing a distributed circuit breaker in Polly has tended towards (/I haven't wanted to implement it without) a quorum-driven approach: break locally if any >=N upstream nodes in the distributed circuit have broken.

Do you think the quorum aspect is important, or am I over-egging this?

[reisenberger]

Proposal for DistributedCircuitBreaker now posted as #287

[reisenberger]

Closing as duplicate, main discussion now on #287