On 1 Aug 2018, at 04:09, Michael Brodhead mkb_cbr@mac.com wrote:

Those of you running relays on low-RAM hosts, what do you do about DirCache?

When I first brought up my relay I noticed this message in the logs:

[warn] Being a directory cache (default) with less than DIRCACHE_MIN_MEM_MB MB of memory is not recommended and may consume most of the available resources, consider disabling this functionality by setting the DirCache option to 0.

That’s not a very helpful message, because it doesn’t say how many MB. We fixed it in 0.3.4 in https://trac.torproject.org/projects/tor/ticket/20887

When I DirCache to 0 I see another warning:

[warn] DirCache is disabled and we are configured as a relay. This may disqualify us from becoming a guard in the future.

We want to update this warning, too: https://trac.torproject.org/projects/tor/ticket/24312

As it turns out I can increase my VMs memory for free so that’s no big deal. Still, I’m curious. What do people do with relays without much memory? Skip DirCache?

Turning off DirCache is fine, but it means your relay will only be a middle (or exit) relay.

Are there ways to reduce the memory footprint and still cache directory info?

Run Tor 0.2.9, without the new directory cache diff and compression features.

T