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Re: syncrepl multicast MMR

Le 09/02/15 05:15, Howard Chu a écrit :
> Emmanuel Lécharny wrote:
>> Le 08/02/15 13:52, Howard Chu a écrit :
>>> Been thinking this would be worth trying for a while now. Set a config
>>> option for syncprov to send Persist messages to a multicast group
>>> instead of the original TCP session. All the consumers would also join
>>> the group and listen for updates. This would also exercise the
>>> cldap:// support in libldap.
>>>
>>> Implementation details: since datagrams are unreliable, we need to
>>> include sequence numbers on each message, which the consumer can check
>>> to make sure it hasn't missed an update. Moreover, it should be able
>>> to send a request to the provider to resend (over the TCP session) the
>>> message corresponding to a given sequence number.
>>
>> Ok but how do you detect that a consumer has missed an update, if no
>> other update occurs ? You may have some desunchronized server for quite
>> a long period of time if you don't have a mechinism for the consumer to
>> regularly check if it is up to date.
>
> Good point, but easily solved with a periodic keepalive msg.

One more thing : you will have to deal with TLS at some point. There is
a RFC draft
(https://tools.ietf.org/html/draft-keoh-tls-multicast-security-00) that
proposes something, it seems to be 3 years old, and not active anymore.