Max Hofer wrote:
> I have a questiuon regarding the heartbeat messgage exchange.
>
> Currently i have 2 cluster systems, each consisting of 2 node:
> - cluster A consists of nodes A1, A2
> - cluster B consists of nodes B1, B2
>
> All 4 nodes are attached with bonded interface to a tow LAN
> switches SW1 and SW2 (lets call it normal LAN).
>
> A1 and A2 (and B1 and B2) have a direct interconnection where
> the DRBD devices are syncronized plus a serial cable (lets call it
> DRBD LAN)
>
> Thus currently cluster A (and B) use 3 different ways to exchange
> the heartbeat packages:
> - bcast ofer the DRDB LAN
> - ucast using normal lan
> - the serial cable
>
> Now i figured out the cluster A needs states/data from cluster B
> (and vice versa) for some fail-over decisions.
>
> I see 2 possible solutions:
> a) wrting a resource agent which polls the state from the other cluster
> and i use this state
> b) i configure 1 single cib.xml with 2 "sub-clusters"
>
> With sub-cluster i mean certain resource run only on cluster A and other
> resource run only on B.
>
> My question now:
> * what will happen if one of the nodes is disconnected from the normal
> LAN - are the information tunnled over the redundant connections?
>
> Scenario: A1 is disconnected from SW1. A2 still recieves HB packages
> via the serial line and the DRBD LAN. Do B1 and B2 see A1 as dead or
> do the get the information about A1 via A2?
>
> maybe strange scenario but i have it (but unfortunatly i can not test it out
> because some external constraints .... managers! ;-)
I'd suggest starting your thinking by having a single cluster, and using
the heartbeat APIs to exchange messages. You can even do this at a
shell script level ;-).
Or you could write status information into CIB node attributes - which
are automatically distributed... And, clone resources notify you when
your peers come and go.
So, a thought would be a clone resource combined with writing short,
simple state into the node attributes.
But, you didn't give enough detail to know which of these would be best,
or whether any of them would work for you.
--
Alan Robertson <[EMAIL PROTECTED]>
"Openness is the foundation and preservative of friendship... Let me
claim from you at all times your undisguised opinions." - William
Wilberforce
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