What do the numbers in

Circuit handshake stats since last time: 1833867/1833868 TAP, 159257/159257 NTor.

mean? Is it how many of them were completed?

1 Answer 1


Yes, that's correct.

There are two types of circuit handshakes -- the original, called the Tor Authentication Protocol in Ian's paper about it: http://freehaven.net/anonbib/#tap:pet2006 and then the better one, called NTor: https://gitweb.torproject.org/torspec.git/blob/HEAD:/proposals/216-ntor-handshake.txt https://gitweb.torproject.org/tor.git/blob/refs/tags/tor-

You can read about the switch to NTor, and the reason we added the log message you're asking about, in this blog post: https://blog.torproject.org/blog/how-to-handle-millions-new-tor-clients

So yes, the fractions x/y mean that y requests of that circuit handshake type came in, and your relay completed x of them. The rest were refused because your CPU couldn't keep up (by refused I mean that your relay sent back a destroy cell, to tell the client that it isn't going to happen).

On high-bandwidth relays these days, I wouldn't be surprised to learn that many of the TAP handshake requests are still refused. Many of the bots have been cleaned up, but many of them still remain too.

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