Thank you Ben, Yabin I understood the rejoin was illegal. I expected this rejoin would fail with the exception. But I could add the failure node to the cluster without the exception after 2) and 3). I want to know why the rejoin succeeds. Should the exception happen?
Regards, On Tue, Oct 18, 2016 at 1:51 AM, Yabin Meng <yabinm...@gmail.com> wrote: > The exception you run into is expected behavior. This is because as Ben > pointed out, when you delete everything (including system schemas), C* > cluster thinks you're bootstrapping a new node. However, node2's IP is > still in gossip and this is why you see the exception. > > I'm not clear the reasoning why you need to delete C* data directory. That > is a dangerous action, especially considering that you delete system > schemas. If in any case the failure node is gone for a while, what you need > to do is to is remove the node first before doing "rejoin". > > Cheers, > > Yabin > > On Mon, Oct 17, 2016 at 1:48 AM, Ben Slater <ben.sla...@instaclustr.com> > wrote: > >> To cassandra, the node where you deleted the files looks like a brand new >> machine. It doesn’t automatically rebuild machines to prevent accidental >> replacement. You need to tell it to build the “new” machines as a >> replacement for the “old” machine with that IP by setting >> -Dcassandra.replace_address_first_boot=<dead_node_ip>. See >> http://cassandra.apache.org/doc/latest/operating/topo_changes.html. >> >> Cheers >> Ben >> >> On Mon, 17 Oct 2016 at 16:41 Yuji Ito <y...@imagine-orb.com> wrote: >> >>> Hi all, >>> >>> A failure node can rejoin a cluster. >>> On the node, all data in /var/lib/cassandra were deleted. >>> Is it normal? >>> >>> I can reproduce it as below. >>> >>> cluster: >>> - C* 2.2.7 >>> - a cluster has node1, 2, 3 >>> - node1 is a seed >>> - replication_factor: 3 >>> >>> how to: >>> 1) stop C* process and delete all data in /var/lib/cassandra on node2 >>> ($sudo rm -rf /var/lib/cassandra/*) >>> 2) stop C* process on node1 and node3 >>> 3) restart C* on node1 >>> 4) restart C* on node2 >>> >>> nodetool status after 4): >>> Datacenter: datacenter1 >>> ======================= >>> Status=Up/Down >>> |/ State=Normal/Leaving/Joining/Moving >>> -- Address Load Tokens Owns (effective) Host ID >>> Rack >>> DN [node3 IP] ? 256 100.0% >>> 325553c6-3e05-41f6-a1f7-47436743816f rack1 >>> UN [node2 IP] 7.76 MB 256 100.0% >>> 05bdb1d4-c39b-48f1-8248-911d61935925 rack1 >>> UN [node1 IP] 416.13 MB 256 100.0% >>> a8ec0a31-cb92-44b0-b156-5bcd4f6f2c7b rack1 >>> >>> If I restart C* on node 2 when C* on node1 and node3 are running >>> (without 2), 3)), a runtime exception happens. >>> RuntimeException: "A node with address [node2 IP] already exists, >>> cancelling join..." >>> >>> I'm not sure this causes data lost. All data can be read properly just >>> after this rejoin. >>> But some rows are lost when I kill&restart C* for destructive tests >>> after this rejoin. >>> >>> Thanks. >>> >>> -- >> ———————— >> Ben Slater >> Chief Product Officer >> Instaclustr: Cassandra + Spark - Managed | Consulting | Support >> +61 437 929 798 >> > >
