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Subject: Re: Change data by an external process (non cayenne)
From: Andrus Adamchik <andrus@objectstyle.org>
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Date: Thu, 16 May 2013 20:34:45 +0300
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To: user@cayenne.apache.org

Actually if cross-context events are in effect (which is the default), =
invalidating an object from a given ObjectContext will automatically =
invalidate it across peers.=20

I would still approach it via query cache and cache groups though. All =
that is needed is that all contexts access those objects via a query =
instead of storing a direct reference.

Andrus

On May 16, 2013, at 12:14 PM, Markus Reich <markus.reich@markusreich.at> =
wrote:

> :-) sorry, I try it more detailed
>=20
> I have a multiuser Tomcat Webapp, the DB (Oracle) is also updated by =
other
> processes. A refresh is not enough to show the changed data, so my =
idea is
> to make a servlet, which invalidates certain DataObjects (mostly it's =
just
> one) of all thread binded contexts.
> So when the user refreshes the UI and the data gets selected again, =
the
> changed values are shown.
> So it would be enough to make object hollow.
>=20
> Markus
>=20
>=20
> 2013/5/16 Andrus Adamchik <andrus@objectstyle.org>
>=20
>> The question is too generic, so the answer is "yes" :) Could you =
describe
>> the scenario in a bit more detail?
>>=20
>> Also does your interface needs to know when an object is invalidated =
right
>> at that moment or is it enough to make the object "hollow" so that it =
is
>> refetched lazily on next access?
>>=20
>> Andrus
>>=20
>> On May 16, 2013, at 7:52 AM, Markus Reich =
<markus.reich@markusreich.at>
>> wrote:
>>> would it be possible to work with a servlet to invalidate certain
>> objects?
>>>=20
>>> Is there a way to get all ObjectStores of all Threads or is the only
>>> solution to set the DataContext as attribute in the session?
>>>=20
>>>=20
>>> 2013/5/15 Andrus Adamchik <andrus@objectstyle.org>
>>>=20
>>>> I'd use query.setCacheStrategy(..) / query.setCacheGroups(..) to =
cache
>> the
>>>> results, and then define expiration time for a given set of cache =
groups
>>>> for whatever cache provider is in use (EhCache most likely, so this
>> will go
>>>> into ehcache.xml).
>>>>=20
>>>> If you want real-time refresh, EhCache might be configured to =
listen to
>>>> cache group refresh events via JMS. Your external process would =
send
>> such
>>>> events via ActiveMQ (that supports a bunch of command-line friendly
>>>> protocols, not just JMS) whenever the data is changed.
>>>>=20
>>>> Andrus
>>>>=20
>>>>=20
>>>> On May 15, 2013, at 4:28 PM, Markus Reich =
<markus.reich@markusreich.at>
>>>> wrote:
>>>>=20
>>>>> Hi,
>>>>>=20
>>>>> is there really no better way than described here:
>>>>> http://markmail.org/message/plnaj4zj4gxrt6hk
>>>>>=20
>>>>> regards
>>>>> Meex
>>>>=20
>>>>=20
>>>=20
>>>=20
>>> --
>>> *Markus Reich*
>>> Moosbach 28/2
>>> 6392 St. Jakob i.H.
>>> www.markusreich.at / www.meeximum.at
>>> markus.reich@markusreich.at
>>=20
>>=20
>=20
>=20
> --=20
> *Markus Reich*
> Moosbach 28/2
> 6392 St. Jakob i.H.
> www.markusreich.at / www.meeximum.at
> markus.reich@markusreich.at