Help with ippool-dhcp servers (two in redundancy)

Alan DeKok aland at
Mon Oct 30 16:53:32 CET 2017

On Oct 30, 2017, at 10:34 AM, Nataniel Klug <nataniel.klug at> wrote:
> I got into a problem and I am not been able to find a solution. I have a
> scenario where I have two Freeradius IPPool DHCP servers that serve the
> same network. When an equipment send an request for DHCP both servers get
> the same request and one of them reply to it. I want to make a delayed
> response in one of them so I can keep the IP allocation more reliable.

  Unfortunately, v3 doesn't really support that kind of delay.  v4 will, tho. :(

> I am
> getting deadlocks in MySQL when running with two servers and I think this
> is caused by the multiple request in those servers.

  The better solution is to fix MySQL and the queries.  In v3, the queries have a "LIMIT 1" clause, which should help.

  By default, InnoDB locks the whole row (or really the range being SELECTed) for updates.  This is bad.  Better DBs like PostgreSQL don't do that.

  If you're using v3.0.15 with the up-to-date queries, this problem shouldn't happen.

  Alan DeKok.

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