<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><BR><DIV><DIV>On 24 May 2006, at 10:59, Joerg Linge wrote:</DIV><BR class="Apple-interchange-newline"><BLOCKQUOTE type="cite"><P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">Am Mittwoch 24 Mai 2006 11:37 schrieb Bruce Campbell:</FONT></P> <BLOCKQUOTE type="cite"><BLOCKQUOTE type="cite"><P style="margin: 0.0px 0.0px 0.0px 20.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">We considered using a "cache" value for a host status - I think the idea</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 20.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">has merit and would reduce a large number of host checks, especially if</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 20.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">something suddenly happened to a large set of services on one host.</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 20.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">However, we baulked at going ahead because there's bound to be some</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 20.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">subtle situation where this would be undesireable.</FONT></P> </BLOCKQUOTE><P style="margin: 0.0px 0.0px 0.0px 10.0px; font: 12.0px Helvetica; min-height: 14.0px"><BR></P> <P style="margin: 0.0px 0.0px 0.0px 10.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">See the "Workaround for 'Host DOWN' false-positives" thread for another</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 10.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">way of doing it (slurp in the entire status.dat file if you've got a small</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 10.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">installation, submit passive host check results from a service check if</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 10.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">you've got a large installation). Both have the advantage of being driven</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 10.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">by Nagios.</FONT></P> </BLOCKQUOTE><P style="margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica; min-height: 14.0px"><BR></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">There is another Tread<SPAN class="Apple-converted-space"> </SPAN>'Host DOWN' false-positives" on nagios-users.</FONT></P> <P style="margin: 0.0px 0.0px 0.0px 0.0px"><FONT face="Helvetica" size="3" style="font: 12.0px Helvetica">What do you think about that solution ?</FONT></P> </BLOCKQUOTE></DIV><DIV><BR class="khtml-block-placeholder"></DIV>I've just reviewed that thread. Please correct if my summary below is wrong.<DIV><BR class="khtml-block-placeholder"></DIV><DIV>PROBLEM</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>Intermittent connectivity failures across a WAN can give an outage of 1 minute. The host check run by Nagios has max_check_attempts of 10, but since the host check attempts are run immediately without a retry interval, the host will go into a HARD failure state before the WAN recovers.</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>SUGGESTED SOLUTIONS</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>The basic premise is that the host status is a reflection of a suitable service status. There are 3 techniques: </DIV><DIV> 1. Use a dependant service. If this fails, then the host check will be run, which is finding the result of this dependant service via status.dat to use as the actual status</DIV><DIV> 2. Using check_cluster for a similar trick</DIV><DIV> 3. Get a service to submit a host check result</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>This doesn't seem to be the same thing that this thread is about (reducing the amount of invocations of the host check because of non-OK statuses from active or passive checks).</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>While the solutions above do the job of updating the host status, you lose the "specialness" about host checks (invoked on-demand, reachability logic, etc). </DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>Going back to the original problem, would a retry_check_interval for host checks help with this particular case? I'm not sure how this affects Nagios' scheduling because host checks are serialised (although Ethan says this will be changed in <A href="http://nagios.org/development/upcoming.php">http://nagios.org/development/upcoming.php</A>), but this would spread the retry so then the HARD state will not be invoked unless the outage was over a longer period.</DIV><DIV><DIV><DIV><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><DIV><BR class="khtml-block-placeholder"></DIV><DIV>Ton</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV><A href="http://www.altinity.com">http://www.altinity.com</A></DIV><DIV>T: +44 (0)870 787 9243</DIV><DIV>F: +44 (0)845 280 1725</DIV><DIV>Skype: tonvoon</DIV></SPAN></SPAN></SPAN></SPAN></SPAN><BR class="Apple-interchange-newline"></SPAN> </DIV></DIV></DIV></BODY></HTML>