<div dir="ltr"><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Jan 11, 2017 at 10:06 PM, Yates, James C. -ND <span dir="ltr"><<a href="mailto:James.C.Yates.-ND@disney.com" target="_blank">James.C.Yates.-ND@disney.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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I was not expecting that behavior from PgPool. I was under the impression that a failover would not occur unless the primary/master server had issues. </div></blockquote><div><br></div><div>The failover is not limited to the primary/master backend nodes only. But each backend node can be individually configured to allow or disallow the failover in case of a backend error (using backend_flag config), and the tolerance level in case of connectivity issue with <span class="gmail-GINGER_SOFTWARE_mark"><span id="gmail-00be7171-a002-4d3a-89f7-99ee542731fe" class="gmail-GINGER_SOFTWARE_mark"><span id="gmail-cf2e2556-92e9-42d3-82f5-6d5a19bb0d4b" class="gmail-GINGER_SOFTWARE_mark">backend nodes</span></span></span> is also configurable using the Pgpool-II <a href="http://www.pgpool.net/docs/pgpool-II-3.6.1/doc/en/html/runtime-config-health-check.html">health check configurations</a>.</div><div><br></div><div>Also the user provided script (<a href="http://www.pgpool.net/docs/pgpool-II-3.6.1/doc/en/html/runtime-config-failover.html">failover_command</a>) is executed by the Pgpool-II at the time of failover, that is passed with all the information of the master/primary node and the failing node. So in the failover script a user can decide not to take any action when the standby node failover is performed if that is intended.</div><div><br></div><div>I also want to mention about the enhancement made in the Pgpool-II version 3.6, now in the case of standby node failover the sessions not using the failed standby node remains unaffected by failover. </div><div><br></div><div>Thanks</div><div>Best regards</div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div style="word-wrap:break-word">
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<div>On Jan 11, 2017, at 3:32 AM, Muhammad Usama <<a href="mailto:m.usama@gmail.com" target="_blank">m.usama@gmail.com</a>> wrote:</div>
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<div><span style="font-family:helvetica;font-size:12px;font-style:normal;font-variant-caps:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;float:none;display:inline">Hi</span>
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It seems like there was a temporary network glitch/failure between the two data centers around "Jan 05 00:04:29" time triggered the failover of backend node0.<br>
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If we look at the logs of each node around this time we can see that the Pgpool-II nodes in the first data center (dbserver1 and dbserver2) were not able to connect to PostgreSQL on dbserver3 that is located in the second data center, and at the very same time
the Pgpool-II on dbserver3 was also having the connection problem with PostgreSQL located on the first data center on dbserver1. All this points towards the connectivity issue between the two data centers.<br>
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Also, apparently the network issue seems to have resolved after a couple of minutes, but till that time the PostgreSQL node failure was already registered by Pgpool-II on dbserver3 and the failover was triggered.
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<div>Thanks</div>
<div>Best regards</div>
<div>Muhammad Usama</div>
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