Thanks for your replies. I seemed to have found the solution. Perhaps this will help others, so I'll send along what I've found:
I have a VIP on all db servers using IPAddr2. I found this link (to follow) before but executed the instructions on ALL machines, which was my stupidity... http://kb.linuxvirtualserver.org/wiki/Using_arp_announce/arp_ignore_to_disable_ARP Instead, the instructions should be followed for all machines with a VIP *not* running LVS/director. That solves the problem of the wrong machines replying to who-is requests. The only thing left is to make sure the web servers update their arp cache. So, I can execute SendArp on the web servers via an order constraint to they re-ask for the arp address for the director machine. In testing, I had found that the SendArp tool (contrary to what it says) actually *asks* for the arp address, it doesn't send a gratuitous arp like advertised. I hope this helps someone. Thank you all so much for your input! Justin On Wed, 2009-09-09 at 11:13 -0400, E-Blokos wrote: > ----- Original Message ----- > From: <darren.mans...@opengi.co.uk> > To: <pacema...@clusterlabs.org> > Sent: Wednesday, September 09, 2009 10:39 AM > Subject: Re: [Pacemaker] Arp and configuration advice > > > >> Greetings, > >> > >> I have a two webserver/two database server clustered setup. I've got > >> ldirector and LVS managed by pacemaker and configured to be able to > > run > >> on either database machine. > >> > >> I know how to disable ARP for the machine not running ldirector, > >> unfortunately I'm not sure how to dynamically get the webservers to > >> update their ARP cache when ldirector gets moved upon failure. > >> > >> Is it possible to set up a service for the two web servers to delete > >> the > >> ARP cache for the VIP on the event that ldirector gets moved? > > > > The IPaddr2 RA runs send_arp when the start action is called I believe: > > > > > > # > > # Run send_arp to note peers about new mac address > > # > > run_send_arp() { > > ARGS="-i $ARP_INTERVAL_MS -r $ARP_REPEAT -p $SENDARPPIDFILE $NIC > > $BASEIP auto not_used not_used" > > if [ "x$IP_CIP" = "xyes" ] ; then > > if [ x = "x$IF_MAC" ] ; then > > MY_MAC=auto > > else > > MY_MAC=`echo ${IF_MAC} | sed -e 's/://'` > > fi > > ARGS="-i $ARP_INTERVAL_MS -r $ARP_REPEAT -p $SENDARPPIDFILE > > $NIC $BASEIP $MY_MAC not_used not_used" > > fi > > ocf_log info "$SENDARP $ARGS" > > case $ARP_BACKGROUND in > > yes) > > ($SENDARP $ARGS || ocf_log err "Could not send > > gratuitous arps" &) >&2 > > ;; > > *) > > $SENDARP $ARGS || ocf_log err "Could not send gratuitous > > arps" > > ;; > > esac > > } > > > > > > So when the VIP is started on another node, other nodes should be > > notified the IP has changed hosts. Doesn't it work for you? > > > >> > >> I can build my own OCF script to update the arp cache, that's not an > >> issue. I simply don't know how to configure pacemaker to say "Oop. db2 > >> died. Move ldirector to db1 and tell the webservers to update their > > ARP > >> cache". > >> > >> Any suggestions? > >> > >> Thanks in advance! > >> > >> Justin > >> > > > > Regards, > > Darren > > I have also this kind of problem months ago, > ARP was not really updating well I don't know why... > > > > _______________________________________________ > > Pacemaker mailing list > > Pacemaker@oss.clusterlabs.org > > http://oss.clusterlabs.org/mailman/listinfo/pacemaker > > > > -- > > This message has been scanned for viruses and > > dangerous content by MailScanner, and is > > believed to be clean. > _______________________________________________ Pacemaker mailing list Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker
