In this article from Cloudflare, IP rotation is mentioned as a way to protect web servers. How does that work? Is this the same as ordinary load-balancing with failover, or something else?
We have a Hyper-V guest with 4 virtual cores reporting 50% usage total among all the virtual cores. That is, this 50% is what atop and top report, with a complementary 350% of "idle". That means at least in theory, 12.5% of total virtual CPU capacity usage. The same server however, when under that stress, reports network round-trip-times in the TCP stack (i.e. SYN packet one way, SYN-ACK packet back) which is four times larger of what they are otherwise. Notice that this part of a TCP connection doesn't touch other I/O in the machine, e.g. disks. Also, I measured the round-trip times to another server to discard local problems in my network. And we didn't see packet loss.
So, there are two possibilities: either the hypervisor is throttling the VM's kernel, or there is a network queue somewhere adding latency to the packets.
My question here is in order to discard the first possibility: does CPU usage reports for a virtual guest, from inside the guest itself, are moderately accurate?
I want to make a virtual network interface to TCP-proxy a website and have my browser see it through a slow network connection, in order to debug performance issues in the website itself.
So far I managed to set it up in the following way:
ip link add dummy-SLOW type dummy
ifconfig dummy-SLOW 10.54.0.10 up
tc qdisc add dev dummy-SLOW root tbf rate 120kbit latency 200ms burst 1540
and then
socat tcp-listen:443,bind=10.54.0.10,reuseaddr,fork tcp:XXX.XXX.XXX.XXX:443
I also added an alias in /etc/hosts so that I can see the website under the IP address 10.54.0.10 .
Well, I can see the site through this setup, no problem, the address 10.54.0.10 even shows in Chrome devtools. But traffic shaping is not working... I still see too many bytes downloading too fast. How can I get traffic shaping to work?
NOTE: IF there is a way for having the proxy do the throttling, well that also works for me.
I have a network split into through two ethernet segments through a virtual VPN hub.
In the figure, blue is the part of the network that I control. My problem is due to the orange subnetwork, that I don't control, the local path from segment 1 to the internet is not taken (I undestand that it is because it contains one more hop), but instead the much slower path through the vpn ethernet hub is used. I'm a total newbie here, there prebably is a very simple way of taking care of this.
How can I ensure that each segment uses it's local router in preference to the other?
One web application that I'm planning relies in [CUDA]http://www.nvidia.com/object/cuda_home_new.html) for doing heavy math processing. I developed the software at home, but now I'm looking for deployment options. I know that Amazon EC2 provides CUDA hosting, but their instances with CUDA are way too high end and a bit too expensive, at least for the testing stage I have up-front.
Anybody knows where can I get affordable CUDA hosting?