Speeding up WordPress on Azure Web-Apps with ClearDB – Disable Output Buffering in PHP

von | Jun 8, 2015 | Microsoft, Technology, WordPress

WordPress running on Azure Web-Apps (a.k.a Azure Websites) seems to be very slow by default.

If you do some research on the web you’ll notice that most people assume, that the bad performance of the MySQL database by ClearDB is the cause for this problem.

The behaviour of WordPress on Azure Web-Apps with disconnections in the backend, lags and delays also goes exactly in this direction.

Ok, it’s a free database – so I upgraded the database to different paid plans from ClearDB (Venus, Saturn, Jupiter) – without significant success – the website was still slow and had some delays and disconnections.

After that, I tested an Azure Linux VM as MySQL-Server for my WordPress website but I had to find, that the problems were almost the same as with ClearDB.

That was the point where I got doubt that ClearDB is the cause for this issue.

So I got the suspicion, that the PHP version or configuration of my Azure Web-App could be the sticking point – and I was right:

I found out, that PHP’s Output Buffering is the cause for the slowness of WordPress on Azure Web-Apps.

As you can read on http://php.net/manual/en/outcontrol.configuration.php#ini.output-buffering – since version 4.3.5, this directive is by default always ‘Off’  – but not on Azure Websites, it has the value ‘4096’.

Do change this, just create a .user.ini file in your root folder with the following text and restart your website:


output_buffering = Off;


After that you will notice a remarkable speed increase of your WordPress Website.

The combination of WordPress with ClearDB on Azure Web-Apps is certainly not the cheapest solution, but on the other hand you get a reliable, clustered database which is perfectly integrated into Microsoft’s cloud ecosystem – and it can be fast 🙂

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