when all nodes are up, so in latest topology snapshot you can see servers count == servers count you run, then cluster can be activated.
2017-08-02 0:51 GMT+03:00 Raymond Wilson <[email protected]>: > 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:[email protected]] > *Sent:* Tuesday, August 1, 2017 11:59 PM > *To:* [email protected] > *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 <[email protected]> > 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. >
