[pgpool-general: 5185] Re: Architecture Questions

[David Sisk -X (dsisk - TEKSYSTEMS INC at Cisco)]

So, application servers in the West and East regions will talk to a DB primary in the East region thru a WAN?  That's prob not going to work all that well, unless that's an awefully fast/low latency WAN.  You'd be better off in all likelihood to route app traffic to app servers in East, vs routing db protocol traffic across regions, I'd think.

I would see Postgres-BDR (Bi-Directional Replication) + HAProxy as a much better solution in this kind of scenario...little or no worries over a split-brain.  (Unless there's something the app does that BDR does not support...possible, but not all that likely.) Reach out to me if you want details.


David Sisk
Engineer - Software
dsisk at cisco.com
Tel: 
Cisco Systems, Inc.
7025-6 Kit Creek Road PO Box 14987
RESEARCH TRIANGLE PARK
27709-4987
United States
cisco.com


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-----Original Message-----
From: pgpool-general-bounces at pgpool.net [mailto:pgpool-general-bounces at pgpool.net] On Behalf Of Yates, James C. -ND
Sent: Monday, December 19, 2016 2:45 PM
To: pgpool-general at pgpool.net
Subject: [pgpool-general: 5179] Architecture Questions

I have some questions about how best to avoid split brain situations for an upcoming deploy on AWS.  I’ve attached a diagram of the proposed layout.  I’m going to have database and application servers in two AWS regions with a internal corporate network connection between AWS regions.  My big concern is avoiding split brain between regions if my corporate network link between the regions goes down.  My question is should I have an odd number of PgPool servers in each region or more pgPool servers in one region over the other.   Right now I’m planning on running PgPool and the Postgres Database on the same servers.   Planned versions are PgPool 3.5.4 and Postgres 9.5.

See attached PDF for a diagram.