Dear Folks,
On 07/05/07 11:14 +0800, jgomez@infoweapons.com wrote:
>> Dear Folks,
>> We are experiencing occasional problems in re-establishing normal
>> state after the failover pair enter communications-interrupted
>> state.  We are using ISC DHCP server 3.0.4.
>>
>> The failover pair enter communications interrupted when one of the
>> pair begins to re-write its dhcpd.leases file.
>>
>> I was woken at midnight last night again to return them to normal,
>> which I did by restarting the primary member of the pair.
>>
>> 1. Have others experienced this problem?
>> 2. Is there any known patch or fix?
>> 3. Any suggestions on how to go about fixing it?
>> 4. Can I use omapi to help restore communication without restarting
>>    the dhcp server?
>
>hello,
>
>i suggest that you use the latest version of ISC DHCP which is
>dhcp-3.0.5 because some of the older versions won't support DHCP
>Failover.

Yes, I agree that this may help; there is one change that *may* have
some impact.  The changes from 3.0.4 -> 3.0.5 are not great, and I am
arguing for this with some members of my team.  But this is a
production system that looks after more than half a million customers,
so changes are not to be made lightly.  And I was shouted at very
abusively for suggesting this.  I continue to argue for this. 

>yes, u can use omapi protocol to connect to the ISC DHCP server and change
>its state without stopping it.

But how can I use it to change from "Communications-Interrupted" to
"Normal"?  The failover pair should enter the "Normal" state from the
"Communications-Interrupted" state automatically.  The problem is that
from time to time, there is a failure to return to normal
communication, resulting to a night-time call to the on-call phone
under my pillow.

>When the DHCP server is configured to use OMAPI, you can connect to
>it by using an OMAPI client and issue commands to the server. There
>is an interactive OMAPI client called omshell that is ideal for
>simple server changes.

Yes, well, I suppose I need to investigate this by writing a tool in
Perl and then trying it out the next time I'm called out, unless I
finish my hacks to the DHCP server to avoid its prolonged stop for a
250MB lease file rewrite, described in another post to this list.

Does anyone have any ideas about/experience with the communication
failure problem that I attempted to describe in the original post?
-- 
Nick Urbanik http://nicku.org  x-71011 nick.urbanik@optusnet.com.au
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