<HTML dir=ltr><HEAD><TITLE>Re: Failover on a large DHCP system</TITLE>
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<DIV dir=ltr><FONT color=#000000 size=2 face=Arial>So is it that if I am using fail-over mode that I add a static IP via omapi on one server that they both will not handle that IP? </FONT></DIV>
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<DIV dir=ltr><FONT size=2 face=Arial>Brad</FONT></DIV></DIV>
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<FONT size=2 face=Tahoma><B>From:</B> dhcp-users-bounces@lists.isc.org on behalf of Chuck Anderson<BR><B>Sent:</B> Fri 5/8/2009 1:45 PM<BR><B>To:</B> dhcp-users@lists.isc.org<BR><B>Subject:</B> Re: Failover on a large DHCP system<BR></FONT><BR></DIV>
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<P><FONT size=2>On Fri, May 08, 2009 at 11:00:33AM -0600, Nicholas F Miller wrote:<BR>>> On Fri, May 08, 2009 at 10:09:29AM -0600, Nicholas F Miller wrote:<BR>>> > With constant restarts of DHCP and the need for<BR>>> > failover to redistribute the pools on restarts I think the server <BR>>> load and<BR>>> > disk access would be too high.<BR>>><BR>>> The disk access footprint between failover restarts is only the<BR>>> "changes" to the database. It doesn't remirror the lease db every<BR>>> reconnect - they only update each other with any new bindings that<BR>>> ocurred during the blackout.<BR>>><BR>>> With huge numbers of leases, it can be a problem however, as it causes<BR>>> both servers to traverse the entire lease database (in memory) right<BR>>> now.<BR>><BR>> With around 72,000 leases at any given time and 677 pools, should we <BR>> just continue using our current restart methodology or try to implement<BR>> omshell as a way to add/remove the hosts? Since omshell writes its<BR>> changes to the leases file, the changes will survive a restart, ignoring<BR>> the config. This could lead to some interesting troubleshooting if<BR>> something were to go awry.<BR><BR>We are using failover and restarting the server at most every 20<BR>minutes for updates from a database-backed registration system. We<BR>have about 120 pools and about 10,000 addresses in the pools (but not<BR>very full utlization of that overall). The overwhelming majority of<BR>requests match static fixed-addresses.<BR>_______________________________________________<BR>dhcp-users mailing list<BR>dhcp-users@lists.isc.org<BR><A href="https://lists.isc.org/mailman/listinfo/dhcp-users">https://lists.isc.org/mailman/listinfo/dhcp-users</A><BR></FONT></P></DIV></BODY></HTML>