keepalive flag isnt working

[deepakdeore2004]

Version and Runtime

$ vegeta -version
Version:
Commit:
Runtime: go1.14.2 linux/amd64
Date:

Expected Behaviour

connections should not have keepalive when --keepalive off is set

Actual Behaviour

netstat shows keepalive is set for the socket

$ netstat -panto |grep :443 |grep ESTA
(Not all processes could be identified, non-owned process info
 will not be shown, you would have to be root to see it all.)
tcp        0      0 10.244.1.70:33067       142.250.77.132:443      ESTABLISHED -                    keepalive (28.52/0/0)

Steps to Reproduce

1. echo "GET https://www.google.com/" | vegeta attack --duration=10m --rate=3 --keepalive on | vegeta report -every 3s
2. run netstat -panto |grep :443 |grep ESTA in another terminal to see connections details

Additional Context

[Choms]

Hi, on your steps you have --kepalive on, it should be -keepalive=false.

However, and to not open a new issue, I do actually see an issue regarding connections falling back to keepalive, when I specify --rate of 1000 or more, with rate under 500 seems ok but with 1k seems it's reusing connections regardless specifying keepalive false.

I did some research and I see Vegeta's code has references to this library https://cs.opensource.google/go/x/net that was in use originally, but since then I think you are using the built in 'net' library (https://github.com/tsenart/vegeta/blob/master/lib/attack.go#L10). However, these two libraries differ on the Dialer function regarding keepalive:

original (https://cs.opensource.google/go/x/net/+/master:internal/quic/config.go;l=92):

	// an idle connection alive.
	// If zero, keep alive packets are not sent.
	// If greater than zero, the keep alive period is the smaller of KeepAlivePeriod and
	// half the connection idle timeout.

new (https://pkg.go.dev/net@go1.22.0#Dialer):

	// probes for an active network connection.
	// If zero, keep-alive probes are sent with a default value
	// (currently 15 seconds), if supported by the protocol and operating
	// system. Network protocols or operating systems that do
	// not support keep-alives ignore this field.
	// If negative, keep-alive probes are disabled.

so if you are actually using the built in library you should be passing a negative integer here and not a 0 so this works correctly: https://github.com/tsenart/vegeta/blob/master/lib/attack.go#L188

note: I don't usually work with go, this is an educated guess reading through a bit here trying to explain the behavior I'm seeing, hopefully it helps :)

[Choms]

Hi all,

quick update, I did some more testing (using netstat -panto to verify the connections) with the current code it does indeed use for any rate keepalive and retransmissions, I did a custom build changing the line referenced to -1 and now I'm actually seeing connections with keepalive off (though strangely I still see a bunch of retransmissions and one or two sporadic keepalives - but at least now I can see most of the traffic not using keepalive).

Cheers

[deepakdeore2004]

thanks for the reply @Choms
there may be typo in my repoduction steps but i ran same command with keepalive off but still see the keepalives

# vegeta --version
Version: v12.11.1
Commit: 6fbe391628eeeae1adf39522a55078797e6e7f2e
Runtime: go1.20.8 linux/amd64
Date: 2023-10-02T09:05:05Z+0000

echo "GET https://www.google.com/" | vegeta attack --duration=10m --rate=3 --keepalive off | vegeta report -every 3s

root@48ec74f242ab:/# netstat -panto |grep :443 |grep ESTA
tcp        0      0 172.17.0.2:59877        142.250.182.132:443     ESTABLISHED 2926/qemu-x86_64     keepalive (24.63/0/0)
root@48ec74f242ab:/# netstat -panto |grep :443 |grep ESTA
tcp        0      0 172.17.0.2:59877        142.250.182.132:443     ESTABLISHED 2926/qemu-x86_64     keepalive (23.15/0/0)
root@48ec74f242ab:/# netstat -panto |grep :443 |grep ESTA
tcp        0     48 172.17.0.2:59877        142.250.182.132:443     ESTABLISHED 2926/qemu-x86_64     on (0.20/0/0)
root@48ec74f242ab:/# netstat -panto |grep :443 |grep ESTA
tcp        0      0 172.17.0.2:59877        142.250.182.132:443     ESTABLISHED 2926/qemu-x86_64     keepalive (21.24/0/0)
root@48ec74f242ab:/# netstat -panto |grep :443 |grep ESTA
tcp        0      0 172.17.0.2:59877        142.250.182.132:443     ESTABLISHED 2926/qemu-x86_64     keepalive (14.45/0/0)
root@48ec74f242ab:/# netstat -panto |grep :443 |grep ESTA
tcp        0      0 172.17.0.2:59877        142.250.182.132:443     ESTABLISHED 2926/qemu-x86_64     keepalive (11.93/0/0)
root@48ec74f242ab:/# netstat -panto |grep :443 |grep ESTA
tcp        0      0 172.17.0.2:59877        142.250.182.132:443     ESTABLISHED 2926/qemu-x86_64     keepalive (10.53/0/0)
root@48ec74f242ab:/# netstat -panto |grep :443 |grep ESTA
tcp        0     41 172.17.0.2:59877        142.250.182.132:443     ESTABLISHED 2926/qemu-x86_64     keepalive (9.82/0/0)

[Choms]

yeah, for that to work you need to change this line to be -1 instead of 0 https://github.com/tsenart/vegeta/blob/master/lib/attack.go#L188

then recompile Vegeta :)

[deepakdeore2004]

yeah, for that to work you need to change this line to be -1 instead of 0 https://github.com/tsenart/vegeta/blob/master/lib/attack.go#L188

then recompile Vegeta :)

i see, then its a bug, i will wait for the fix, for now i am good with keepalive :-)

[Choms]

yea it's a bug, not sure if this project is still active though