Hi Mikhail,


Thanks for the clarifications.



Yes, I knew setting active was only required when using the persistence
layer, which is the topic of the question J



I was interested if there were best practices or approaches for determining
when the grid had fully initialized. I realise this is somewhat application
specific, but was looking for an established pattern before I invented one
myself.



In my case I have an affinity function that responds to topology changes
which intrinsically would know when it had a ‘quorum’. Is this a typical
place for setting active to true.



Thanks,

Raymond.



*From:* Mikhail Cherkasov [mailto:mcherka...@gridgain.com]
*Sent:* Tuesday, August 1, 2017 11:59 PM
*To:* user@ignite.apache.org
*Subject:* Re: Best practise for setting Ignite.Active to true when using
persistence layer in Ignite 2.1



Hi Raymond,



Ignite cluster is inactive on startup only if persistence is enabled. This
is done to avoid unnecessary partition exchanges between nodes,

for example, if you have 3 nodes and 1 backup enabled and you start only 2
of 3 nodes, then they will treat the third node as dead and start process

of restoring data from backup and rebalance data to spread them among 2
nodes, when you add the missed third node back the process will be repeated.



So we start cluster as in active. When all nodes are started and ready, so
no cluster topology changes aren't expected, you should activate cluster.



Also when you turn off cluster, some nodes can still accept request for
data update and other nodes won't see it, so understand which node has the
latest

data we need to start all nodes first and only then activate cluster.



Thanks,

Mikhail.



On Tue, Aug 1, 2017 at 5:05 AM, Raymond Wilson <raymond_wil...@trimble.com>
wrote:

Hi,



I am experimenting with a POC looking into using the Ignite persistence
layer.



One aspect of this is setting the grid to be ‘Active’ after all cache grid
nodes have instantiated.



In practical terms, what is the best practice for ensuring the cluster is
running and in a good state to be set to active? What is the downside of
setting active to true before all grid nodes are running?



Thanks,

Raymond.







-- 

Thanks,

Mikhail.

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