Hi, On Thu, Apr 19, 2012 at 3:56 PM, Parshvi <parshvi...@gmail.com> wrote: > 1) What is the use of ssh without pass key between cluster nodes in pacemaker > ? > a. Use case: > i. Two nodes in a cluster (Call them Node-1 and Node-2) > ii. One interface configured in corosync.conf for its heartbeat or > messaging. Eg. Bind net addr : 192.168.10.0 > iii. Another interface configured in /etc/hosts for hostname resolution. > Eg. IP: 192.168.129.10 Hostname: Node-1 > Eg. IP: 192.168.129.11 Hostname: Node-2 > iv. Hence for all ssh communication between the two nodes, hostname > resolves > to subnet 129 address. > v. 12 services configured in active/passive mode > vi. 1 service configured in master/slave mode > vii. 8 services are non-sticky (they failback) in active/passive > viii. 4 services are sticky (do not failback) in active/passive > ix. Distribution: Node-1 is primary for 8 services (of which 4 are non- > sticky), Node-2 is preferred for 4 services of a total 12 (non-sticky) > > b. Observations: > i. On Node-2, the interface was down over which IP: 192.168.129.11 > Hostname: > Node-2 was configured. > ii. On Node-1 all interfaces were up. > iii. Interface used by corosync for hearbeat/messaging was up at all times > (Bind net addr : 192.168.10.0) > iv. In crm_mon: Node-1 sees Node-2 as offline > cibadmin --query fails to work (remote node did not respond) > v. In crm_mon: Node-2 sees Node-1 as online > vi. All the services were seen active on Node-1 (including those that were > preferred for Node-2). Observed in crm_mon output. > vii. 4 services for which Node-2 was preferred were seen active Node-2 also > (hence 4 services active on both the nodes). > Observed in crm_mon output: Only 4 services were shown active, the status > of > the rest of the services active on Node-1 did not reflect in crm_mon > Even though crm_mon on Node-2 sees Node-1 as “online”. > c. Errors in log file: > i. On Node-2: > 1. Resource ocf::RscRA:rsc appears to be active on 2 nodes > 2. The above error appears for all the resources configured in pacemaker. > > > Query: > 1) For what purpose does Pacemaker require “ssh without a pass key” to be > enabled between the nodes in a cluster ?
scp > 2) For what purpose does Pacemaker use Node “hostname” for ? how Node > “hostname” > come into picture ? When choosing where to allocate resources not explicitly tied to a node. See http://www.clusterlabs.org/doc/en-US/Pacemaker/1.1/html-single/Pacemaker_Explained/#node-score-equal and http://www.clusterlabs.org/doc/en-US/Pacemaker/1.1/html-single/Pacemaker_Explained/#_background > 3) Let’s say in a two node cluster two communication paths are available > between > the two nodes. > a. Eth1 and eth2. > b. The hostname of the node resolves to IP Address on eth1. > c. Consider, eth1 (network cable disconnected) goes down. > d. Eth2 is up, but hostname does not resolve to the IP on eth2 (resolves to > eth1 addr). Inter-node communication is usually specified by IP address, and redundant connections (as in your case) is recommended. > e. Will this (hostname) have any issue ? > > > > > _______________________________________________ > Pacemaker mailing list: Pacemaker@oss.clusterlabs.org > http://oss.clusterlabs.org/mailman/listinfo/pacemaker > > Project Home: http://www.clusterlabs.org > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf > Bugs: http://bugs.clusterlabs.org -- Dan Frincu CCNA, RHCE _______________________________________________ Pacemaker mailing list: Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
