On Thu, Mar 04, 2021 at 01:09:55PM +0100, Michael Ströder wrote:
On 3/4/21 12:20 PM, Ondřej Kuzník wrote:
If it takes 1 second to replicate a change and a previous change happened x seconds before this one there's going to be a window of 1 second where you see an x second CSN difference between the provider and consumer. In no way does it mean the consumer is x seconds behind.
I'm talking about the contextCSN difference being visible for several *hours* while the changes have been already successfully replicated. Replication delay is very short, syncrepl type is refreshAndPersist.
Don't think I've ever seen this outside slapcat (only checkpoints affect the on-disk version). Please submit a bug if you can replicate this.
If there's an acceptable delay of n seconds, you better wait for that amount of time before raising an alarm,
And what's an appropriate value for n? 86400? ;-]
Depends where in the galaxy you place your replicas :)
See the logic in syncmonitor[0]
Ideally I'd like to query cn=monitor whether slapd thinks replication is in a healthy state.
Consumer will never think its replication is slow/broken (unless it gets an actual error and you can already see that in cn=monitor). Provider might want to expose some information but that's not implemented yet and will not be able to spot many issues if other providers exist.