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From Udo Kohlmeyer <...@apache.org>
Subject Re: [DISCUSS] TTL setting on WAN
Date Wed, 20 Mar 2019 17:51:38 GMT
-1, I don't believe this is a feature that we should support. IF a 
client is experiencing slow WAN replication and users only care about 
the "latest" data, then maybe the user should use "conflation".

With a TTL model, we are messing with our consistency tenet. I'm am NOT 
in support of a setting that can cause inconsistency.

Dead-letter queues is another area that WILL cause data/site 
inconsistency. I think we really have to take a step back, think about 
WHAT tenets are important to GEODE and then act accordingly.

--Udo

On 3/20/19 10:46, Bruce Schuchardt wrote:
> IDK Anil, we'll figure that out in the implementation.  I was thinking 
> it would be in the dispatch threads, so if distribution is need that 
> will happen as it does now.  I'm hopeful that this won't perturb the 
> code too much.
>
> One thing that was brought up to me in person was the Dead Letter 
> Queue 
> <https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=80452478> 
> initiative that seems to have stalled.  That seems like a very similar 
> idea though it's reacting to errors coming from the receiving side and 
> not a local condition.  I like the callback, stats, gfsh and cluster 
> config integration in that write-up & think they might be useful 
> here.  There is also relevant discussion in that page about things 
> like PDX registrations.  Is that initiative going to move forward at 
> some point or is it off the boards?
>
> On 3/20/19 10:25 AM, Anilkumar Gingade wrote:
>> +1. Will the expiration (destroy) be applied on local queues or the
>> expiration will be replicated (for both serial and parallel)?
>>
>> -Anil.
>>
>>
>> On Wed, Mar 20, 2019 at 8:59 AM Bruce Schuchardt 
>> <bschuchardt@pivotal.io>
>> wrote:
>>
>>> We've seen situations where the receiving side of a WAN gateway is slow
>>> to accept data or is not accepting any data.  This can cause queues to
>>> fill up on the sending side.  If disk-overflow is being used this can
>>> even lead to an outage.  Some users are concerned more with the latest
>>> data and don't really care if old data is thrown away in this
>>> situation.  They may have set a TTL on their Regions and would like to
>>> be able to do the same thing with their GatewaySenders.
>>>
>>> With that in mind I'd like to add this method to GatewaySenderFactory:
>>>
>>> /** * Sets the timeToLive expiration attribute for queue entries for 
>>> the
>>> next * {@code GatewaySender} created. * * @param timeToLive the
>>> timeToLive ExpirationAttributes for entries in this region * @return a
>>> reference to this GatewaySenderFactory object * @throws
>>> IllegalArgumentException if timeToLive is null * @see
>>> RegionFactory#setEntryTimeToLive */ public GatewaySenderFactory
>>> setEntryTimeToLive(ExpirationAttributes timeToLive);
>>>
>>> The exact implementation may not be the same as for Regions since we
>>> probably want to expire the oldest entries first and make sure we do so
>>> in their order in the queue.
>>>
>>>
>

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