Strange Surge In Traffic

[RedBar]

I had a strange "thing" happen on my Linux server using Plesk 12.0 and I'm not sure where to post the question!

A site that normally uses about 8 GB bandwidth per month was suddenly hit with a demand for 12+ GB early Saturday morning seemingly shortly after Baidu and Bingbot spiders had just been through.

This shot it through its monthly allowance and suspended its service and I didn't realise for a few hours before unsuspending it and getting it back up again.

The strange thing is we had no traffic spike and seemingly no DDOS attack, the raw logs show nothing, bang, it just went off.

Has anyone any idea of what may have happened? All my other sites on this server were unaffected.

[penders]

If your "logs show nothing", where is the 12+ GB reported? What does your host say?

[RedBar]

Host said:

"I already checked for unusually activity, but could not see anything odd, but granted, usage is higher. Are you running WordPress or similar CMS?

Certainly no denial of service has taken place."

I don't use WP or a CMS.

where is the 12+ GB reported?

On the Domain's page under Resource Usage and the domain's Statistic's page showing 16.5 GB of http usage as of today, normally it would only be a max of 5 GB up to this point of the month.

[penders]

Does your site connect to any others, server to server?

[RedBar]

Nope, FWIW traffic since the "surge" has been steady however I am convinced the server is not as smooth nor as fast as it was.

[not2easy]

Do you check you own access logs? That would answer the question of what is causing the additional bandwidth usage and what/where it is coming from.

[RedBar]

Yep, I have those logs and whatever did it killed them dead in one go, they simply stopped and as I wrote my host couldn't even see anything untowards.

I'm slowly getting through them inbetween jobs but, as yet, nothing stands out.