@Mike - correct me if I am wrong, and I wouldn't recommend this, but... You could emulate a pub/sub system even with peers by taking advantage of a Subscription <http://geode.incubator.apache.org/docs/guide/reference/topics/cache_xml.html#subscription-attributes> [1] policy on peer *Regions* (REPLICATE or PARTITION, either or). I.e. a Region's Subscription policy controls what data is replicated between them, which in effect, could serve a similar purpose to topics and what data events a peer Region receives. Then a CacheListener registered on the Region could process events when entries (of interests expressed through the Region Subscription policy) are updated.
Of course, this is a superficially limited approach and not advisable for any practical use of a Region's Subscription policy, IMO. First, you would need to pre-populate the Region with keys (for events) you are interested in. Then, you would set the Subscription interest-policy to "cache-content" where your peer would then be notified of updates from any other peer also defining the same Region and, as well, also storing the same key/value. So, as you can see, this is not a intended use of this feature, but it is doable. You can read additional information here <http://geode.incubator.apache.org/docs/guide/developing/events/configure_p2p_event_messaging.html> [2]. As @Mike points out, a better approach it to use the client/server topology <http://geode.incubator.apache.org/docs/guide/topologies_and_comm/cs_configuration/chapter_overview.html> [3] and Register Interests <http://geode.incubator.apache.org/docs/guide/developing/events/configure_client_server_event_messaging.html> [4], or better yet, use CQs <http://geode.incubator.apache.org/docs/guide/developing/continuous_querying/chapter_overview.html> [5]. Hope this helps. Cheers, John [1] http://geode.incubator.apache.org/docs/guide/reference/topics/cache_xml. html#subscription-attributes [2] http://geode.incubator.apache.org/docs/guide/developing/events/configure_p2p_event_messaging.html [3] http://geode.incubator.apache.org/docs/guide/topologies_and_comm/cs_configuration/chapter_overview.html [4] http://geode.incubator.apache.org/docs/guide/developing/events/configure_client_server_event_messaging.html [5] http://geode.incubator.apache.org/docs/guide/developing/continuous_querying/chapter_overview.html On Mon, Nov 14, 2016 at 2:57 PM, Michael Stolz <mst...@pivotal.io> wrote: > Ok Got it. > But Peer caches can't do pub/sub unless they go to the extra trouble of > setting up a pool, whereas clients get a pool automatically. > > -- > Mike Stolz > Principal Engineer, GemFire Product Manager > Mobile: 631-835-4771 > > On Mon, Nov 14, 2016 at 3:02 PM, John Blum <jb...@pivotal.io> wrote: > >> Well, what I think Amit means (correct me if I am wrong) is the Geode >> embedded peer cache use case, meaning the application is also a peer cache >> in the cluster, while not the most common UC (nor maybe recommended in most >> UCs), it is a valid UC none-the-less. >> >> It is to have your application participate a peer in the Geode cluster by >> simply constructing a peer Cache using the CacheFactory >> <http://geode.incubator.apache.org/releases/latest/javadoc/org/apache/geode/cache/CacheFactory.html> >> [1], >> and setting the locators property have your application join existing >> cluster, something like so... >> >> Cache peerCache = new CacheFactory().set("locators", >> "<host>[<port>]").set(..)...create(); >> >> You can also do this in SDG with... >> >> <util:properties id="geodeProperties"> >> <prop key="name">MyApplication</prop> >> <prop key="mcast-port">0</prop> >> <prop key="log-level">${geode.log.level:config}</prop> >> <prop key="locators">${geode.locators.host-port:localhost[10334]}</prop> >> <prop key="start-locator">${geode.locator.embedded.host-port:}</prop> >> </util:properties> >> >> <gfe:cache properties-ref="geodeProperties"/> >> >> The <gfe:cache> element created a "peer" cache (as opposed to the >> <gfe:client-cache> element). >> >> You are then free to create Regions used by your application as necessary. >> >> I have examples of both GemFire peer and client/server configurations >> here <https://github.com/jxblum/pivotal-gemfire-clientserver-examples> [2] >> and here >> <https://github.com/jxblum/contacts-application/tree/apache-geode> [3] >> (see configuration examples). >> >> Hope this helps. >> >> Cheers, >> John >> >> [1] http://geode.incubator.apache.org/releases/latest/javado >> c/org/apache/geode/cache/CacheFactory.html >> [2] https://github.com/jxblum/pivotal-gemfire-clientserver-examples >> [3] https://github.com/jxblum/contacts-application/tree/apache-geode >> >> >> On Mon, Nov 14, 2016 at 11:28 AM, Michael Stolz <mst...@pivotal.io> >> wrote: >> >>> Geode clients have the ability to registerInterest(key) which works a >>> lot like a topic. >>> >>> Not sure what you mean by using Geode embedded and with a cluster of >>> external processes, but what I THINK you're asking is, can you use the >>> Geode client/server model where the client is embedded into your >>> application process and the servers that are responsible for holding all >>> the data are in a separate cluster. The answer is YES, that is the most >>> common configuration for Geode usage. >>> >>> >>> >>> -- >>> Mike Stolz >>> Principal Engineer, GemFire Product Manager >>> Mobile: 631-835-4771 >>> >>> On Sat, Nov 12, 2016 at 12:41 PM, Amit Pandey <amit.pandey2...@gmail.com >>> > wrote: >>> >>>> Hi Guys, >>>> >>>> Is there any example of public subscribe with geode? Hazelcast and >>>> Ignite seem to have topics, is there any such thing in Geode. >>>> >>>> Also I want to use Geode embedded. Can I use it with a cluster of >>>> external processes as well. >>>> >>>> Regards >>>> >>> >>> >> >> >> -- >> -John >> 503-504-8657 >> john.blum10101 (skype) >> > > -- -John 503-504-8657 john.blum10101 (skype)
