[ClusterLabs] Corosync ifdown / ifup crash with Assertion `token_memb_entries >= 1' failed.

Dennis Jacobfeuerborn dennisml at conversis.de
Tue Jun 2 12:32:09 EDT 2015

On 02.06.2015 12:57, Jan Friesse wrote:
> Alexander,
> Alexander T napsal(a):
>> Jan,
>> Thank you for the explanation. What do you mean by "knet migration" in
>> Corosync 3.0?
> We are planning to replace current network related code with knet.
> Basically currently we have multicast, udpu and IBA (infiniband)
> transport. Problem with multicast is mainly in badly configured
> switches, because many network admins believe multicast is evil + some
> switches are really bad in multicast. IBA code is almost unmaintained.
> So last is UDPU. UDPU works quite well, but still, it's just 1:1 rewrite
> of multicast where multicast is simulated by sending messages to all
> configured members. Still all weird requirements and weird code base
> remains.

I don't think it's switches that are the problem these days but the fact
that in many environments multicast isn't available at all (e.g. clouds)
and even if it is it might still be a pain to get working. If you want
to create a cluster of virtual machines for example you need to know the
magic incantation for /proc to make multicast work.
Given that a lot of people only set up 2-node clusters anyway unicast is
the easiest way to get things working.

> Last but not least is RRP. RRP itself works very well sadly it works in
> totally different way then most of people expects.
> Solution is knet (http://www.kronosnet.org/). Knet should give corosync
> proper support for multiple NICs (like software bonding), very fast
> reaction time to link failure, proper handling of MTU, ...

That has no documentation whatsoever and what little communication there
was on the mailing lists was in 2010. Are you sure it's a good idea to
rely on a project that seems to be dead?


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