CODEWITHSUNDEEP
azurelatency
Yoshi Walsh
Yoshi Walsh

Reputation: 2077

Extremely high latency on Azure Web App

We currently self-host our website, but we've had a few downtime incidents outside of our control and we're looking at moving it into Azure. It's an ASP.NET website using Umbraco as the CMS.

Yesterday I signed up for an Azure trial, migrated a copy of our database onto an Azure SQL Server instance, spun up a new Web App and used Web Deploy to upload the app. This was my first experience with Azure, and I was pleasantly surprised at how easy it was. There were a few issues working out how to hook up my new app to my new database but overall it was a simple process.

But the performance is awful. The database is a Standard S2 and I initially created the web app on the Free tier. I was experiencing both poor download speed and latency. The first thing I tried was bumping up the Web App's scale, so I took it to Standard Medium. This seems to have fixed the download speed, but the latency is still impressively bad.

I'm using Google Chrome's network panel to test the speed. Here's what I get downloading an image from our server:

On-prem low latency

Obviously this is going to be fast as it's going over our local network, but this does at least show that the application is not the issue.

Here's what I get with Standard S2 hosted on Australia East:

Azure high latency

The speed once the download has started is not too bad, but having a 41.92s TTFB is insane! It's not consistent, sometimes I get as low as 8s, but that's still unacceptable.

I don't have this issue when visiting other sites, so my internet is not the issue. I've tried using Small S2 and Large S2 with no change in results.

Am I doing something wrong? I find it difficult to believe that every Azure customer experiences this level of performance.

EDIT: Here's what we've learned in the comments so far:

Setting Always On does not help.

Using the Azure CDN is just as slow.

Upvotes: 3

Views: 2348

Answers (2)

Paul Franke
Paul Franke

Reputation: 649

I also had enormous performance problems within the Azure environment. The cause was the activation of Applications Insights. After I deactivated it, the response times were again in the millisecond range and no longer 2-3 seconds.

Upvotes: 1

Yoshi Walsh
Yoshi Walsh

Reputation: 2077

This was an issue with my own network's configuration. I'm not sure how to resolve it, but I can't reproduce this issue when using my phone's internet so it's clearly not an Azure problem.

Upvotes: 0

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