On Thu, Jan 14, 2021 at 02:46:35PM -0800, Quanah Gibson-Mount wrote:
Hi Janne,
And thank you for the answer. I found out that the replication source is actually a redundant two node installation with MirrorMode [1] replication between the nodes.
Is this game changer? Can I add two syncrepl providers to the consumer's slapd configuration? If it's not possible I think one provider is enough.
You can have multiple syncrepl stanzas on a consumer. However it's not clear to me how things will behave with what you're proposing, so YMMV.
Yeah. The way I've solved something like this is that I have two consumers that form a redundant pair using keepalived, and both of them have one half of the mirrormode-replicating pair as a provider. In my case, I don't actually care that the active consumer may be following an inactive provider (and so have old data). If that's a problem with you, you could figure out a way for the consumers' keepalived to follow what's going on with the providers, and relinquish master status in the consumer pair if the provider they're following is out.
I don't know if the openldap proxy can be used as a syncrepl provider - if it can, you might experiment with that: you could have the consumer use the proxy as the provider, and the proxy could have both members of the mirrored pair as backends. The proxy code selects the backend that is quicker to respond, so always replies if at least one of the backends is alive.
Best,
Janne