[Openais] Two questions; Intro to AIS? and TOTEM errors in fence loop

[Madison Kelly]

Hi all,

   I've been playing with clustering on CentOS 5.x lately and thus far 
I've not really understood AIS' role in it. I've been to the AIS website 
but there isn't much there.

   So my first question is; Where can I go to learn the fundamentals of AIS?

   Second question relates to a real-world problem I've been having. 
I've got a pretty 2-node simple cluster running DRBD+LVM on eth1. I use 
eth0 between the two nodes as a back channel which connects to an 
internal network via which we can manage the servers with IPMI. Lastly, 
there is eth2 on each node that is Internet-facing.

   So far, I can't put eth0 under Xen control (that is, I can't have it 
virtualized on dom0) without it causing a fence loop. I've tried asking 
for help elsewhere but some far I've not heard back.

   The reason I am asking here now is that the node that gets fenced 
shows this in it's logs several times just before going down:

Oct 31 00:27:21 vsh02 openais[3133]: [TOTEM] FAILED TO RECEIVE
Oct 31 00:27:21 vsh02 openais[3133]: [TOTEM] entering GATHER state from 6.

   On the surviving node I see this:

Oct 31 00:35:47 vsh03 openais[3237]: [TOTEM] The token was lost in the 
OPERATIONAL state.
Oct 31 00:35:47 vsh03 openais[3237]: [TOTEM] Receive multicast socket 
recv buffer size (288000 bytes).
Oct 31 00:35:47 vsh03 openais[3237]: [TOTEM] Transmit multicast socket 
send buffer size (262142 bytes).
Oct 31 00:35:47 vsh03 openais[3237]: [TOTEM] entering GATHER state from 2.
Oct 31 00:35:51 vsh03 openais[3237]: [TOTEM] entering GATHER state from 0.
Oct 31 00:35:51 vsh03 openais[3237]: [TOTEM] Creating commit token 
because I am the rep.
Oct 31 00:35:51 vsh03 openais[3237]: [TOTEM] Saving state aru 2c high 
seq received 2c
Oct 31 00:35:51 vsh03 openais[3237]: [TOTEM] Storing new sequence id for 
ring 108
Oct 31 00:35:51 vsh03 openais[3237]: [TOTEM] entering COMMIT state.
Oct 31 00:35:51 vsh03 openais[3237]: [TOTEM] entering RECOVERY state.
Oct 31 00:35:51 vsh03 openais[3237]: [TOTEM] position [0] member 
10.255.135.3:
Oct 31 00:35:51 vsh03 openais[3237]: [TOTEM] previous ring seq 260 rep 
10.255.135.2
Oct 31 00:35:51 vsh03 openais[3237]: [TOTEM] aru 2c high delivered 2c 
received flag 1
Oct 31 00:35:51 vsh03 openais[3237]: [TOTEM] Did not need to originate 
any messages in recovery.
Oct 31 00:35:51 vsh03 openais[3237]: [TOTEM] Sending initial ORF token
Oct 31 00:35:51 vsh03 openais[3237]: [CLM  ] CLM CONFIGURATION CHANGE
Oct 31 00:35:51 vsh03 openais[3237]: [CLM  ] New Configuration:
Oct 31 00:35:51 vsh03 kernel: dlm: closing connection to node 1
Oct 31 00:35:51 vsh03 fenced[3256]: vsh02.domain.com not a cluster 
member after 0 sec post_fail_delay
Oct 31 00:35:51 vsh03 openais[3237]: [CLM  ]     r(0) ip(10.255.135.3)
Oct 31 00:35:51 vsh03 fenced[3256]: fencing node "vsh02.domain.com"

   This happens when I put eth0 under Xen's management. The nodes will 
keep fencing until DRBD breaks. At that point, the fencing stops and 
everything seems to be fine. However, once I fix the DRBD partition and 
try to look at the LVM the above errors return and I'm right back into a 
fence loop until DRBD breaks again.

   Even a pointer to where I can learn more about AIS/TOTEM so that I 
can try to understand what's going on would be awesome. I'm really stuck 
on this error...

Thanks!

Madi