On 6/27/2007 3:20 PM, Andrew Sullivan wrote:
> On Wed, Jun 27, 2007 at 10:12:31AM +0800, Dewi Andriyanti wrote:
>> I intend to build a replication system via VPN using Slony but I need more
>> reference. Is Slony good in data integrity, consistency, reliability and
>> response time? Is Slony better than PGCluster? What is drawbacks of Slony?
>> Would anybody help me to share stable configuration for replication system
>> via VPN using Slony?
> 
> What's the bandwidth available inside the VPN?  You need to make sure
> you can propagate the changes fast enough.  I don't believe PGCluster
> can work over wide areas -- I think it has to be local.

On a connection with limited bandwidth (like Internet) I experienced 
that using a VPN with data compression will actually increase the Slony 
communication. There is definitely a turning point where the overhead of 
compression doesn't keep up with the network bandwidth. Where exactly 
that is depends on the speed of whatever does the compression and of 
course the bandwidth. As with all benchmarks, you have to test YOUR case 
yourself.


Jan

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