Heavy load due to ajax calls

Hi there,

we are developing a potentially big network site with your theme, which by the way is excellent. We have been working on this since end of last year.

Today we had a conference call with our customer and altogether 3 people accessed the site at the same time. Then suddenly I got a warning due to high server load (this is our own server). Looking at htop I see 6-7 tasks running at max cpu load and the total load is at 100%. See the CPU load graph in the attachement.

So I finished the call and started to look into the issue. It turns out, that it is simply open browser windows/tabs, that each produce some load, but alltogether adding up to the above. Looking into the transfer logs, I see that each window/tab is being refreshed every 5 seconds, resulting in the 100% cpu load with only 3 people and each having a few open browser windows. You can see an excerpt of the log in the attached file.

Surely this is a bug, right? We are expecting to have a few thousand visitors, so even a fraction of that load would kill that site.

Is this something you encountered before? As mentioned, we have been working on the site for quite some time and never experienced anything like this so far, so I would tend to say this must be a new thing/bug.

Let me know what you need from us or how we can get this debugged.

Cheers,

Michael