<div dir="ltr">Hey Mark,<div><br></div><div>This kind of environment is certainly possible, we do a lot of work with PGPool in AWS achieve some great results.</div><div><br></div><div>Generally speaking you can just have a pair of PGPool instances linked with Watchdog and then put a load balancer in front of them. This can be an AWS ELB, an appliance like an F5 or a software load balancer HAProxy. </div><div><br></div><div>In all of these cases you just need to teach the load balancer how to health check PGPool - most of the time a TCP check will do.</div><div><br></div><div>In combination with this you need to tell PGPool not to worry about the virtual IP address - you can do this by setting delegate_IP to nothing.</div><div><br></div><div>This will create an ACTIVE/ACTIVE PGPool environment, requests can come in to both nodes and be serviced, if one goes down then the load balancers will notice and remove it from the pool.<br></div><div><br></div><div>If you control your database failover with PGPool this will work out of the box, if you control it with another product (linuxHA, repmgr, EnterpriseDB PPFM) then you will need to teach that product how to fence PostgreSQL nodes using either the AWS API or the PGPool PCP API.<br></div><div><br></div><div>Hope that helps.</div><div><br></div><div>Cheers,</div><div><br></div><div><br></div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature"><div style="color:#b8276a;font:bold 14px Arial,Helvetica,sans-serif">
<br>
<span style="color:#323b62">James Sewell,</span><br>
<span style="color:#a9a9a9"><span style="font:12px Arial,Helvetica,sans-serif">PostgreSQL Team Lead / Solutions Architect </span></span><br>
<span style="color:#a9a9a9">______________________________________</span><br>
</div>
<img alt="" src="http://www.lisasoft.com/sites/lisasoft/files/u1/logo1.jpg" style="margin:0px;width:153px;height:50px"><br>
<div style="font:normal 12px/20px Arial,Helvetica,sans-serif;color:#404040;margin:0">
<span style="color:#a9a9a9">Level 2, 50 Queen St, Melbourne VIC 3000</span><br>
<br>
<strong>P </strong><span style="color:#a9a9a9"><span style="font-family:Arial,Verdana,sans-serif">(+61) 3 8370 8000</span></span><span style="color:rgb(169,169,169)"> </span><strong> </strong><span style="color:rgb(50,59,98)"><span style="width:15px;display:inline-block"><strong>W</strong></span></span> <a style="color:rgb(64,64,64);margin:2px 0px;text-decoration:none"><span style="color:#a9a9a9">www.lisasoft.com</span></a> <span style="color:rgb(50,59,98)"><span style="width:15px;display:inline-block"><strong>F </strong></span></span><span style="color:#a9a9a9"><span style="font-family:Arial,Verdana,sans-serif">(+61) 3 8370 8099</span></span></div>
<div style="padding-top:8px">
</div></div></div>
<br><div class="gmail_quote">On Tue, May 5, 2015 at 8:23 AM, Mark Kirkwood <span dir="ltr"><<a href="mailto:mark.kirkwood@catalyst.net.nz" target="_blank">mark.kirkwood@catalyst.net.nz</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi,<br>
<br>
The watchdog examples all seem to expect that ppgool itself can control the ip to host allocation. While this works fine in my test setup, we are looking at deploying this in a more cloud-like environment where pgpool (and for that matter the hosts too) *cannot* change their own networking (in fact they may not even know their world accessible ips).<br>
<br>
Another type of config we are looking at is where an external load balancer controls the redirection to the pgpool hosts.<br>
<br>
So is it possible to setup a watchdog type arrangement, but with *something else* (as above) controlling the ip allocation?<br>
<br>
<br>
Cheers<br>
<br>
Mark<br>
_______________________________________________<br>
pgpool-general mailing list<br>
<a href="mailto:pgpool-general@pgpool.net" target="_blank">pgpool-general@pgpool.net</a><br>
<a href="http://www.pgpool.net/mailman/listinfo/pgpool-general" target="_blank">http://www.pgpool.net/mailman/listinfo/pgpool-general</a><br>
</blockquote></div><br></div></div>
<br>
<p><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14.545454025268555px;background-color:rgb(255,255,255)"><hr><font size="1" color="Gray" face="Arial">The contents of this email are confidential and may be subject to legal or professional privilege and copyright. No representation is made that this email is free of viruses or other defects. If you have received this communication in error, you may not copy or distribute any part of it or otherwise disclose its contents to anyone. Please advise the sender of your incorrect receipt of this correspondence.</font></div></p>