>From within...
class MyTransactionListener extends TransactionListenerAdapter {
public void commit(TransactionEvent event) {
List<CacheEvent<?, ?>> cacheEvents = event.getEvents();
// Null check shouldn't be necessary but...
// I don't trust the Geode API to do the right thing and...
// I have seen issues like this before, so better safe than sorry!
if (events != null) {
cacheEvents.stream()
.filter(Objects::nonNull) // Also should not be necessary but...
.filter(CacheEvent::isOriginRemote)
.ifPresent(cacheEvent -> // now persist the event or do
whatever you need to do);
}
}
-j
On Mon, Jan 20, 2020 at 5:29 AM Alberto Bustamante Reyes
<alberto.bustamante.re...@est.tech> wrote:
> Thanks Charlie! In that case, what could be a good approach to
> differentiate locally generated events from replicated events?
> If you use a TransactionListener and a region to store and replicate
> transaction objects, you would need that differentiation for not applying
> twice the local transactions.
> ------------------------------
> *De:* Charlie Black <cbl...@pivotal.io>
> *Enviado:* sábado, 18 de enero de 2020 0:32
> *Para:* user@geode.apache.org <user@geode.apache.org>
> *Asunto:* Re: WAN replication of transactions
>
> Take a look at Transaction Listener - the tranaction listener can get all
> of the objects in the transaction. That could then be put into a
> transaction object that gets transmitted over wan as single message. Just
> do a put of all that you need to another region.
>
> Just a thought.
>
>
>
> On Fri, Jan 17, 2020 at 1:36 PM Alberto Bustamante Reyes
> <alberto.bustamante.re...@est.tech> wrote:
>
> Thanks for your answers, thats what I understood from documentation.
>
> Then I see a potential point of failure. If a transaction in site-1 is not
> completely sent to site-2, you have to ensure that applications using the
> inconsistent data of site-2 are able to detect that or are prepared to
> handle it.
>
> After reading the documentation, I was wondering if it could be possible
> to send all events of a transaction using the same dispatcher thread of a
> serial sender with "partition" policy taking into account that regions
> involved on the transaction are colocated. Doing this, each batch of events
> sent would contain almost only complete transactions.
>
> BR/
>
> Alberto
> ------------------------------
> *De:* Eric Shu <e...@pivotal.io>
> *Enviado:* viernes, 17 de enero de 2020 19:35
> *Para:* user@geode.apache.org <user@geode.apache.org>
> *Asunto:* Re: WAN replication of transactions
>
> The transaction is not supported across the wan sites.
>
> If inconsistent state occurred due to a network problem between the wan
> sites, the inconsistency would exist during the network outage. However,
> once the network problem is resolved, the wan gateway would resume sending
> the events again. Two sides would be eventually consistent.
>
> The persistence and redundancy mentioned by Anil would be useful if the
> senders are down (HA scenario).
>
> Regards,
> Eric
>
> On Fri, Jan 17, 2020 at 6:48 AM Anilkumar Gingade <aging...@pivotal.io>
> wrote:
>
> Currently in Geode events are not transactional (WAN events, Client/server
> subscription events). To enable guaranteed event delivery It provides
> capability like persistence and redundancy.
>
> -Anil.
>
> On Fri, Jan 17, 2020 at 3:01 AM Alberto Bustamante Reyes
> <alberto.bustamante.re...@est.tech> wrote:
>
> Hi all,
>
> I have a question about transactions and WAN replication. If a transaction
> generates an event for each operation, is it possible to ensure that those
> operations are received together on the other site?
>
> There is a risk of having a site with an inconsistent state if there is a
> network problem. Lets say you have two sites, and communication between
> them is broken when not all events of a transaction on site 1 where sent to
> site 2. How are you dealing with this risk? Have someone experimented this?
>
> Thanks,
>
> BR/
>
> Alberto
>
>
> --
> Charlie Black | cbl...@pivotal.io
>
--
-John
Spring Data Team
