Wait 30 seconds between posts. Wtf?

[PrincessBandit]

I have, only of recent days, been experiencing an occurrence whereby I click on "submit post" only to have an error message come up saying "you must wait 30 seconds between posts" then my post shows up twice in the thread. This then requires me to delete the second one.
Anyone else have this?

[steve_t]

I think it's a feature that Spank may be able to turn off. In another forum I'm on, you have to wait 30 seconds between searches... it sux

[p.dath]

I think it's a feature that Spank may be able to turn off. In another forum I'm on, you have to wait 30 seconds between searches... it sux

It happens when the site is really busy. Note than when it happens (and you have only done one post) you don't need to do anything. Even though you have been given a warning, the post is still made. If you wait 30s and click the "Post" button again you get a double post.

I think what is happening under the hood is if the browser does not get a response for 30s it re-transmits the request. So the site ends up getting two post requests, even though you only made one.

I suspect this will be a short lived issue and will self resolve. it was especially evident when the indexing was occurring.

EDIT: I think it corresponds with spikes in the I/O wait for the kernel (shown in purple on this graph):
http://www.kiwibiker.co.nz/monitorix/imgs/kern1z.day.png

EDIT EDIT: I still think that 200 interrupts/second for the network card is high. That means the CPU is being interrupted every 5ms just to service the network card. That's a lot of wasted context switches (and hence CPU power). Should be using something DMA driven.

[newbould]

EDIT: I think it corresponds with spikes in the I/O wait for the kernel (shown in purple on this graph):
http://www.kiwibiker.co.nz/monitorix/imgs/kern1z.day.png

EDIT EDIT: I still think that 200 interrupts/second for the network card is high. That means the CPU is being interrupted every 5ms just to service the network card. That's a lot of wasted context switches (and hence CPU power). Should be using something DMA driven.
Wot he said.
Graphs and 3 letter acronyms do it for me every time.