[mrsirduke]

I took me a while to find gor, and it seems that there aren't many tools for traffic duplication/replication out there.

If you know of any tools like gor, I'd very much like to know of them.

[molf]

There's httap: https://github.com/rolftimmermans/httap

[zoratu]

At the higher end of the performance scale there are commercial options using specialized hardware and commercial software. Building block cost is ~$300k/20Gbps (~400K rps) of replay traffic, but scales out with parallel deployments.