[ClusterLabs] cluster loses state (randomly) every few minutes.

[lejeczek]

hi guys,

I have a very basic two-node cluster, not even a single 
resource on it, but very troublesome - it keeps braking.
Journal for 'pacemaker' shows constantly (on both nodes):
...
warning: Input I_DC_TIMEOUT received in state S_PENDING from 
crm_timer_popped
  notice: State transition S_ELECTION -> S_PENDING
  notice: State transition S_PENDING -> S_NOT_DC
  notice: Lost attribute writer swir
  notice: Node swir state is now lost
  notice: Our peer on the DC (swir) is dead
  notice: Purged 1 peer with id=2 and/or uname=swir from the 
membership cache
  notice: Node swir state is now lost
  notice: State transition S_NOT_DC -> S_ELECTION
  notice: Removing all swir attributes for peer loss
  notice: Purged 1 peer with id=2 and/or uname=swir from the 
membership cache
  notice: Node swir state is now lost
  notice: Node swir state is now lost
  notice: Recorded local node as attribute writer (was unset)
  notice: Purged 1 peer with id=2 and/or uname=swir from the 
membership cache
  notice: State transition S_ELECTION -> S_INTEGRATION
  warning: Blind faith: not fencing unseen nodes
  notice: Delaying fencing operations until there are 
resources to manage
  notice: Calculated transition 0, saving inputs in 
/var/lib/pacemaker/pengine/pe-input-627.bz2
  notice: Transition 0 (Complete=0, Pending=0, Fired=0, 
Skipped=0, Incomplete=0, 
Source=/var/lib/pacemaker/pengine/pe-input-627.bz2): Complete
  notice: State transition S_TRANSITION_ENGINE -> S_IDLE
  notice: Node swir state is now member
  notice: Node swir state is now member
  notice: Node swir state is now member
  notice: Node swir state is now member
  notice: State transition S_IDLE -> S_INTEGRATION
  warning: Another DC detected: swir (op=noop)
  notice: Detected another attribute writer (swir), starting 
new election
  notice: Setting #attrd-protocol[swir]: (unset) -> 2
  notice: State transition S_ELECTION -> S_RELEASE_DC
  notice: State transition S_PENDING -> S_NOT_DC
  notice: Recorded local node as attribute writer (was unset)

It's the same hardware on which "this same" cluster ran okey 
and then, only a couple of days ago, I upgraded Centos on 
these two boxes to "Steam"
I'm hoping it's something trivial I'm missing with new 
version(s) of software came with upgrace, perhaps some (new) 
settings for two-node cluster which I missed.
Any suggestions greatly appreciated.
many thanks, L.