Hi Steve, Just to make it clear. Do you mean that in the above case If N3 is part of the network, it should have connectivity to both N2 and N1 and if it happens so that N3 has connectivity to N2 only, corosync doesnot take care of the same.
Regards, Ranjith On Sat, Sep 25, 2010 at 9:39 AM, Steven Dake <sd...@redhat.com> wrote: > On 09/24/2010 08:20 PM, Ranjith wrote: > >> Hi , >> It is hard to tell what is happening without logs from all 3 nodes. Does >> this only happen at system start, or can you duplicate 5 minutes after >> systems have started? >> >>> >> The cluster is never stabilizing. It keeps on switching between the >>> >> membership and operational state. >> Below is the test network which i am using: >> >> Untitled.png >> >>> >> N1 and N3 does not reveive any packets from each other. Here what i >>> >> expected was that either (N1,N2) or (N2, N3) forms a two node cluster >> and stabilizes. But the cluster is never stabilizing even though 2 node >> clusters are forming, it is going back to membership [I checked the logs >> and it looks like because of the steps i mentioned in the previous mail, >> this seems to be happening] >> >> >> > ...... Where did you say you were testing a byzantine fault in your > original bug report? Please be more forthcoming in the future. Corosync > does not protect against byzantine faults. Allowing one way connectivity in > network connection = this fault scenario. You can try coro-netctl (the > attached script) which will atomically block a network ip in the network to > test split brain scenarios without actually pulling network cables. > > Regards > -steve > > >> Regards, >> Ranjith >> On Fri, Sep 24, 2010 at 11:36 PM, Steven Dake <sd...@redhat.com >> <mailto:sd...@redhat.com>> wrote: >> >> It is hard to tell what is happening without logs from all 3 nodes. >> Does this only happen at system start, or can you duplicate 5 >> minutes after systems have started? >> >> If it is at system start, you may need to enable "fast STP" on your >> switch. It looks to me like node 3 gets some messages through but >> then is blocked. STP will do this in it's default state on most >> switches. >> >> Another option if you can't enable STP is to use broadcast mode (man >> openais.conf for details). >> >> Also verify firewalls are properly configured on all nodes. You can >> join us on the irc server freenode on #linux-cluster for real-time >> assistance. >> >> Regards >> -steve >> >> >> On 09/22/2010 11:33 PM, Ranjith wrote: >> >> Hi Steve, >> I am running corosync 1.2.8 >> I didn't get what u meant by blackbox. I suppose it is >> logs/debugs. >> I just checked logs/debugs and I am able to understand the below: >> 1--------------2--------------3 >> 1) Node1 and Node2 are already in a 2node cluster >> 2) Now Node3 sends join with ({1} , {} ) (proc_list/fail_list) >> 3) Node2 sends join ({1,2,3} , {}) and Node 1/3 updates to >> ({1,2,3}, {}) >> 4) Now Node 2 gets consensus after some messages [But 1 is the rep] >> 5) Consensus timeout fires at node 1 for node 3, node1 sends join >> as >> ({1,2}, {3}) >> 6) Node2 updates because of the above message to ({1,2}, {3}) >> and sends >> out join. This join received by node 3 causes it to update >> ({1,3}, {2}) >> 7) Node1and Node2 enter operational (fail list cleared by node2) >> but >> node 3 join timeout fires and again membership state. >> 8) This will continue to happen until consensus fires at node3 >> for node1 >> and it moves to ({3}, {1,2}) >> 9) Now Node1and Node2 from 2 node cluster and 3 forms a single >> node cluster >> 10) Now node 2 broadcast a Normal message >> 11) This message is received by Node3 as a foreign message which >> forces >> it to go to gather state >> 12) Again above steps .... >> The cluster is never stabilizing. >> I have attached the debugs for Node2: >> (1 - 10.102.33.115, 2 - 10.102.33.150, 3 -10.102.33.180) >> Regards, >> Ranjith >> >> On Wed, Sep 22, 2010 at 10:53 PM, Steven Dake <sd...@redhat.com >> <mailto:sd...@redhat.com> >> <mailto:sd...@redhat.com <mailto:sd...@redhat.com>>> wrote: >> >> On 09/21/2010 11:15 PM, Ranjith wrote: >> >> Hi all, >> Kindly comment on the above behaviour >> Regards, >> Ranjith >> >> On Tue, Sep 21, 2010 at 9:52 PM, Ranjith >> <ranjith.nath...@gmail.com <mailto:ranjith.nath...@gmail.com> >> <mailto:ranjith.nath...@gmail.com >> <mailto:ranjith.nath...@gmail.com>> >> <mailto:ranjith.nath...@gmail.com <mailto: >> ranjith.nath...@gmail.com> >> <mailto:ranjith.nath...@gmail.com >> <mailto:ranjith.nath...@gmail.com>>>> wrote: >> >> Hi all, >> I was testing the corosync cluster engine by using the >> testcpg exec >> provided along with the release. I am getting the below >> behaviour >> while testing some specific scenarios. Kindly >> comment on the >> expected behaviour. >> 1) 3 Node cluster >> 1---------2---------3 >> a) suppose I bring the nodes 1&2 up, it will form >> a >> ring (1,2) >> b) now bring up 3 >> c) 3 sends join which restarts the membership >> process >> d) (1,2) again forms the ring , 3 forms self >> cluster >> e) now 3 sends a join (due to join or other >> timeout) >> f) again membership protocol is started as 2 >> responds >> to this >> by going to gather state ( i believe 2 should not >> accept >> this as 2 >> would have earlier decided that 3 is failed) >> I am seeing a continuous loop of the above >> behaviour ( >> operational -> membership -> operational -> ) due to >> which the >> cluster is not becoming stabilized >> 2) 3 Node Cluster >> 1---------2-----------3 >> a) bring up all the three nodes at the same >> time (None >> of the >> nodes have seen each other before this) >> b) Now each node forms a cluster by itself .. >> (Here i >> think it >> should from either a (1,2) or (2,3) ring ) >> Regards, >> Ranjith >> >> >> >> >> Ranjith, >> >> Which version of corosync are you running? >> >> can you run corosync-blackbox and attach the output? >> >> Thanks >> -steve >> >> >> _______________________________________________ >> Openais mailing list >> Openais@lists.linux-foundation.org >> <mailto:Openais@lists.linux-foundation.org> >> <mailto:Openais@lists.linux-foundation.org >> <mailto:Openais@lists.linux-foundation.org>> >> >> https://lists.linux-foundation.org/mailman/listinfo/openais >> >> >> >> >> >> >
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