Sql Azure Region Latency Comparison Melbourne Australia

April 27, 2013

I’ve just got back from the Melbourne edition of the Global Windows Azure Bootcamp. While I was there I got to run some tests on region latency for Azure. That is, over the connection at the conference centre, I was able to create and test every data centre region available to us for latency or delay of the connection. The conference centre were using a connection supplied by ISP Exetel. I repeated this test a few hours later at home over a Bigpond cable connection.

To perform the test I followed the advice of the Microsoft SQL Azure Team blog. I created a database on a server in each region. I enabled “Include Client Statistics” and I executed the statement “SELECT 1” on each one 10 times, waiting about a second each time before re-executing. The times shown below are the average “Wait Time On Server Replies” times. If you want to know why this is relevant, please see the original article here.

So at between 2:30pm and 3:30pm on Saturday, I was able to determine the following latencies for Exetel:

Region Latency
East Asia 179.7ms
South East Asia 180.2ms
West US 185.2ms
South Central US 229ms
East US 232ms
North Central US 268ms
Western Europe 311.4ms
Northern Europe 339.5ms

At between 6pm and 7pm over the Telstra Bigpond connection, I got the following latencies:

Region Latency
South East Asia 110ms
East Asia 143.8ms
West US 168.8ms
South Central US 199.1ms
North Central US 229.7ms
East US 237.4ms
Western Europe 321.9ms
Northern Europe 327.2ms

So what does this mean? Firstly, it means that you really need to test latency of each region depending on what locations your application is targeted to. Secondly, because latency is dependent on which ISP that is connecting to your application, you really need to pick a region close to you.

Exetel was about equivalent in East Asia, South East Asia and West US. However, Bigpond was far better in South East Asia at the times of the test. So in this case, it would be safest to locate in South East Asia, because you’ll get the best results on the two ISPs. But remember, I did the test on Saturday, afternoon, and it’s not exactly a high traffic time. It would be interesting to see what the statistics looks like on a Thursday night at around 5:30pm.