On Thu, Apr 19, 2012 at 11:51 PM, Dan Frincu <df.clus...@gmail.com> wrote: > 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
But pacemaker doesn't use scp... or is this in relation to the clusters from scratch document? -ECONFUSED > >> 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 _______________________________________________ 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
