Hello Valentin, and thank you. On 30/10/15 23:55, "vkulichenko" <[email protected]> wrote:
>The list of addresses in the IP finder is the list of addresses that node a >node will try to make initial connect when joining topology. Actually, this >list is usually the same on all nodes and there is no need to provide >addresses of all nodes in the system. Even one is enough, you just need to >make sure that the node on this address is started first. But of course, >it's a good practice to add 2-3 more for redundancy. This is what I deduced from the code. Assuming a moderate size installation (say, 10-20 servers, dozens of persistent nodes per server), each installation governed by an automated controller/watchdog, how would one go about starting that one special initial case? From my perspective, nodes have to be equal, and there is no manual intervention after software updates or disaster recoveries - there are lots of installations, and everything has to be automated. (It would be rare for everything to be down at once, that's true, but it could happen in some special updates, or recovering from a catastrophic power failure.) In an ideal world, I would just use multicast discovery, where none of this is an issue, but that is not an option here. I could derive a trivial or fancy leader election process to launch that initial seed at the controller/watchdog level. Or, I could write a TcpDiscoveryIpFinder extension that works with an already existing discovery system (but I suspect I'd have to elect a leader anyway to avoid a split cluster scenario). Or, I could look into decoupling the announce/join logic in org.apache.ignite.spi.discovery.tcp.ServerImpl and submitting a patch. Just to confirm, what would the Ignite topology be after the following sequences? Node A starts (no peers) Node B starts (no peers) Node C starts, connects to A Node D starts, connects to B -- I assume here we will have two isolated clusters Node E starts, connects to A, B -- Do we now get a unified topology spanning all nodes? >If anything is still unclear, please provide your current configuration and >details of your deployment (how many physical servers and how many nodes per >server you have). Any use of Ignite is hypothetical at this point, but I hope the above gives some context. Cheers, //eb
