How to debug "Got POOLREQ, answering negatively"?

sthaug at sthaug at
Mon Apr 20 17:27:50 UTC 2009

> My thinking lately has been for the peer (sending the POOLREQ) to
> also provide one of the addresses in the pool it thinks is misbalanced
> enough to generate the response.  The receiving server could use the
> address to find the pool, and would only balance this one pool in this
> case.  We could also lift the restriction that the server only send
> one POOLREQ at a time (now you could send 5 for the 5 specific pools
> you care about).  It sounds like we could add the peer's
> active/free/backup statistics for logging purposes.

Sounds like a good solution to me.

> I'm also debating if we should take more stringent action on a
> negative answer to a POOLREQ.  Something like taking a trip through
> potential-conflict, but this worries me.  This could self-heal db
> inconsistencies (which has the unfortunate side effect that we'd
> probably stop hearing about db inconsistency bugs).

How about an option which defaults to *logging* info to identify
the inconstency, but which can be explicitly configured to also
self-heal? If you want to be clever, make it configurable only by
OMAPI, so you know it is turned off next time the dhcpd process is

And while I'm in wishlist mode - it would be great to have a document
which specifies *exactly* what is necessary for two lease files, one
from the primary and one from the secondary, to be consistent.

> And so long as we're talking, it would be great for there to be
> some way other than the hex-printed address in memory of the pool
> structure to uniquely name a pool.  :(

Absolutely. But as long as the actual IP address is logged together
with the hex address in "balancing pool"/"balanced pool" messages,
I can live with the hex addresses.

> For the time being, I think you should be able to check the peer's
> logfile, as its balance run entry for the pool in question will
> indicate its desire to request rebalance (I think it logs this even
> if multiple pools want to send POOLREQ...I think it appends
> "requesting pool rebalance!" or something).

Yes, that's how I verified I was on to the right pool, after I had
identified it through other means.

Steinar Haug, Nethelp consulting, sthaug at

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