Given how slow protobufs and grpc is, I wonder if the socket transport would ever be the throughout bottleneck here.
Changing transports means if you want to move your grpc server process to a different box you now have new runtime configuration to implement/support and new performance characteristics to test.
I can see some of the security benefits if you are running on one host, but I also don't buy the advantages highlighted at the end of the article about using many different OS's and language environments on a single host. Seems like enabling and microptimising chaos instead of taming it.
Particularly in the ops demo: Statically linking a C++ grpc binary and standardising on host OS and gcc-toolset doesn't seem that hard. On the other hand, if you're using e.g. a python rpc server are you even going to be able to feel the impact of switching to vsock?
Says it is fast, but presents zero benchmarks to demonstrate it is actually fast or even “faster”. It is shameful to make up adjectives just to sound cool.
vsock is pretty widely used, and if you're using virtio-vsock it should be reasonably fast. Anyway if you want to do some quick benchmarks and have an existing Linux VM on a libvirt host:
(1) 'virsh edit' the guest and check it has '<vsock/>' in the <devices> section of the XML.
(2) On the host:
$ nbdkit memory 1G --vsock -f
(3) Inside the guest:
$ nbdinfo 'nbd+vsock://2'
(You should see the size being 1G)
And then you can try using commands like nbdcopy to copy data into and out of the host RAM disk over vsock. eg:
$ time nbdcopy /dev/urandom 'nbd+vsock://2' -p
$ time nbdcopy 'nbd+vsock://2' null: -p
On my machine that's copying at a fairly consistent 20 Gbps, but it's going to depend on your hardware.
To compare it to regular TCP:
host $ nbdkit memory 1G -f -p 10809
vm $ time nbdcopy /dev/urandom 'nbd://host' -p
vm $ time nbdcopy 'nbd://host' null: -p
It's actually copying the data. Splicing wouldn't be possible, since NBD is a client/server protocol.
The difference between nbdcopy ... /dev/null and nbdcopy ... null: is that in the second case we avoid writing the data anywhere and just throw it away inside nbdcopy.
Given how slow protobufs and grpc is, I wonder if the socket transport would ever be the throughout bottleneck here.
Changing transports means if you want to move your grpc server process to a different box you now have new runtime configuration to implement/support and new performance characteristics to test.
I can see some of the security benefits if you are running on one host, but I also don't buy the advantages highlighted at the end of the article about using many different OS's and language environments on a single host. Seems like enabling and microptimising chaos instead of taming it.
Particularly in the ops demo: Statically linking a C++ grpc binary and standardising on host OS and gcc-toolset doesn't seem that hard. On the other hand, if you're using e.g. a python rpc server are you even going to be able to feel the impact of switching to vsock?
Says it is fast, but presents zero benchmarks to demonstrate it is actually fast or even “faster”. It is shameful to make up adjectives just to sound cool.
vsock is pretty widely used, and if you're using virtio-vsock it should be reasonably fast. Anyway if you want to do some quick benchmarks and have an existing Linux VM on a libvirt host:
(1) 'virsh edit' the guest and check it has '<vsock/>' in the <devices> section of the XML.
(2) On the host:
(3) Inside the guest: (You should see the size being 1G)And then you can try using commands like nbdcopy to copy data into and out of the host RAM disk over vsock. eg:
On my machine that's copying at a fairly consistent 20 Gbps, but it's going to depend on your hardware.To compare it to regular TCP:
TCP is about 2.5x faster for me.Is nbdcopy actually touching the data consumer side or is splicing to /dev/null ?
It's actually copying the data. Splicing wouldn't be possible, since NBD is a client/server protocol.
The difference between nbdcopy ... /dev/null and nbdcopy ... null: is that in the second case we avoid writing the data anywhere and just throw it away inside nbdcopy.
Ah, thanks. That is a much better example than the one in the article.
This is interesting. I wasn't familiar with vsock.
I think the use of Bazel and gRPC in the article distracts from understanding how vsock works. I found this article[1] much more approachable.
[1]: https://medium.com/@F.DL/understanding-vsock-684016cf0eb0