David Goulet:
On 17 Oct (13:54:22), Arlen Yaroslav via tor-relays wrote:
Hi,
Hi Arlen!
I've done some further analysis on this. The reason my relay is being marked as overloaded is because of DNS timeout errors. I had to dive into the source code to figure this out.
In dns.c, a libevent DNS_ERR_TIMEOUT is being recorded as an OVERLOAD_GENERAL error. Am I correct in saying that a single DNS timeout error within a 72-hour period will result in an overloaded state? If so, it seems overly-stringent given that there are no options available to tune the DNS timeout, max retry etc. parameters. Some lower-specced servers with less than optimal access to DNS resolvers will suffer because of this.
Correct, 1 single DNS timeout will trigger the general overload flag. There were discussion to make it N% of all request to timeout before we would report it with a N being around 1% but unfortunately that was never implemented that way. And so, at the moment, 1 timeout is enough to trigger the problem.
And I think you are right, we would benefit on raising that threshold big time.
FWIW: that's tracked in
https://gitlab.torproject.org/tpo/core/tor/-/issues/40491
We had that on our radar previously but it fell through the cracks. :(
Georg