On May 16 23:07:39, fischer+o...@lavielle.com wrote:
> >> around full minutes, full 5 minutes, etc. This was most likely caused
> >> by bunching up of requests from cron tasks around those times.
> >
> > Do you mean cron tasks running at the (many) _clients_ using that server?
>
> Exactly. A public DDNS service will typically have many thousands of clients.
> And while not all of them will access the server at any particular time, the
> numbers of requests do go up with the number of clients. Add to that that
> some clients send unnecessary requests, and that certain times are more
> popular than others, and the observed result was peaks in server load at
> certain times.
>
> After all, the most simple client would just get the current public IPs and
> update the server, triggered by cron every minute. (This effectively amounts
> to a DoS-attack :-( )
>
> In this case some mitigation was possible within the existing constraints.
> But the real solution is to get most of the clients to be better behaved.
To be clear: you want to make thousands of clients do this cron dance,
so that they don't hit your server at the same time?
If you are telling them that,
you can just as well tell them to only run it at ~/10
> I don’t know the exact numbers as I’m not an administrator of that service.
I'm confused again: are you trying to school the clients
of someone else's server?
Jan
