[389-users] Re: Expected Write/Read Behavior in a Supplier/Consumer scenario...

On 07/03/2018 10:25 AM, David Boreham wrote:
>
>
> On 7/2/2018 2:54 PM, Artur Lojewski wrote:
>> Question: If I issue a delete operation to a read-only replica, and
>> the delete request ist properly resend to the actual supplier, can I
>> expect (?) that an immediate read to the consumer does not find the
>> deleted object?
> Note : you wrote "ist" above. I'm assuming this should be "is" (not
> "isn't")
> No. Nothing will have changed in the consumer's database (hence :
> read-only).
>> Or do I have to wait until the supplier initiated replication
>> (immediate) has taken place?
> Yes.
>>
>> The current behavior his that I still can read back the "deleted"
>> object from the read-only replica until the replication is over. Is
>> that correct behavior?
> Yes.
>> Or can I 'tweak' things that even on a read-only replica a deleted
>> object is immediately not available, even before replication starts.
>>
> No.
>
> The servers implement "async" or "eventually consistent" replication.
> Clients have to deal with stale reads.
What you can do is instead of having a read-only consumer is you could
just use two masters.  Then the delete would be intimidate on that
server, but you'd still have to wait for replication to send the delete
to the other master.

The issue is if you plan to add a lot of replicas.  You don't want to
have 20 masters, although people do it.  It's just a lot of repl
agreements and changelog contention, etc.

Regards,
Mark
>
>
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