Hi,

On the subject of parallel gateway sender receivers, according to the Geode 
documentation:

[1]:
Although parallel gateway senders provide the best throughput for WAN 
distribution, they provide less control for event ordering. Event ordering for 
the region as a whole is not preserved, because multiple Geode servers 
distribute the regions events at the same time. However, the ordering of events 
for a given partition can be preserved. See Configuring Multi-Site (WAN) Event 
Queues.

[2]:
You cannot configure the order-policy for a parallel event queue, because 
parallel queues cannot preserve event ordering for regions. Only the ordering 
of events for a given partition (or in a given queue of a distributed region) 
can be preserved.


Given that the documentation seems to state that the ordering of events can be
preserved for a given partition when using parallel gateway senders, my 
question is how can this be achieved when using several gateway receivers.

Example:
Suppose we have a WAN deployment with 2 clusters, one with parallel gateway 
senders and a remote one with several gateway receivers.

Entry1 is updated twice consecutively as follows:
- First update: attribute1 = 3
- Second update: attribute1 = 5

As a result of the previous updates on Entry1, the gateway sender running on 
the server hosting the bucket where Entry1 is stored will send two events to 
the remote cluster that has several gateway receivers.

Could each event be sent to a different server or to the same server but over 
two different connections?
If this is possible, the order of arrival of the events to the server hosting 
the primary replica would not be guaranteed to be the same as the original one. 
Right? If this is the case, how would the ordering be preserved? Would 
timestamps be used?

Thanks in advance,

/Alberto G.


[1] 
https://geode.apache.org/docs/guide/12/topologies_and_comm/topology_concepts/multisite_overview.html

[2] 
https://geode.apache.org/docs/guide/12/developing/events/configuring_gateway_concurrency_levels.html


Reply via email to