Hi,
> it created a near cache on each server node
There are two Near Cache modes:
* Server Node Near Cache - configured once before cache start for all
server nodes
* Client Node Near Cache - configured dynamically on per-node basis
Please make sure to use the second mode, like explained in the docs [1]:
ignite.getOrCreateNearCache("myCache", nearCfg);
https://ignite.apache.org/docs/latest/configuring-caches/near-cache#creating-near-cache-dynamically-on-client-nodes
On Sat, Feb 20, 2021 at 4:06 AM tschauenberg <tschauenb...@invidi.com>
wrote:
> Hi,
>
> I have a use case where I want a fully copy of a replicated cache on a
> subset of my thick clients. In this example, I have an ETL thick client
> that creates and updates a replicated cache in my server grid. I then have
> a series of webserver thick clients that I always want a fully up to date
> copy of that cache.
>
> NearCache Attempt:
> =============
> I tried using a NearCache on the webserver thick clients but this had two
> undesireable problems:
> * it created a near cache on each server node which I have no use for since
> this is already an replicated cache
> * the near cache never received new entries from the replicated cache, it
> was only updated with entries it had already had stored in it.
>
> Is there a way I can resolve either of these two undesireable problems of
> the NearCache for my situation?
>
>
> Continuous Query Attempt:
> =================
> This lead me to instead consider Continuous Queries (CQ) where I would have
> each webserver maintain it's own Map of the server cache data where upon
> startup it uses the CQ initial query to get the current server state on
> startup and then uses the CQ local listener.
>
> Trying to get the CQ working I followed the examples in text in
> https://ignite.apache.org/docs/latest/configuring-caches/near-cache
> however
> I can only see the local listener updates if I run the query in my own
> thread that I never let finish.
>
> What am I doing wrong in the code below?
>
> Continuous Query code:
> ---------------------------
>
> // Create new continuous query.
> val qry = ContinuousQuery<Int, String>()
>
> // have it return all data in its initial query
> // Setting an optional initial query.
> qry.setInitialQuery(ScanQuery())
>
> // don't set a remote filter as we want all data returned
> // qry.setRemoteFilterFactory()
>
> // Callback that is called locally when update notifications are received.
> qry.setLocalListener { events ->
> println("Update notifications
> starting...[thread=${Thread.currentThread()}]")
> for (e in events) {
> println("Listener event: [thread=${Thread.currentThread()},
> key=${e.key}, val=${e.value}]")
> }
> println("Update notifications finished
> [thread=${Thread.currentThread()}]")
> }
>
> val executor = Executors.newSingleThreadExecutor()
> executor.submit {
> myCache.query(qry).use { cur ->
>
> // Iterating over initial query results
> println("Initial query cursor
> starting...[thread=${Thread.currentThread()}]")
> for (e in cur) {
> println("Cursor value: [thread=${Thread.currentThread()},
> key=${e.key}, val=${e.value}]")
> }
> println("Initial query cursor finished
> [thread=${Thread.currentThread()}]")
>
> println("Starting holding continuous query cursor open so we can
> get
> callback data... [thread=${Thread.currentThread()}]")
> val shouldBeRunning = true
> while (shouldBeRunning) {
> // hold this thread open forever so the local listener callback
> can keep processing events
> try {
> Thread.sleep(5000)
> } catch (e: InterruptedException) {
> println("Continuous query sleep interrupted
> [thread=${Thread.currentThread()}]")
> throw e
> }
> }
> println("Stopping holding continuous query cursor open because we
> got shutdown signal [thread=${Thread.currentThread()}]")
> }
> }
>
>
>
>
>
> --
> Sent from: http://apache-ignite-users.70518.x6.nabble.com/
>
