Hi, I have noticed that after a few minutes of becoming online, and randomly perhaps a couple of times every hour (??) tor uses 100 % processor on all cores for about 40/50 seconds. I am curious what is tor doing internally to need so much power? There is normally isn't more than 4 mbits going through my relay, I noticed this a while back on htop before the December load increase and on previous versions so this has got to be an "internal thing". There is no log entry when this happens. I do not think it is a bug I am just curious why it needs this much computational power, Thanks.
On 5 Feb 2018, at 23:21, Gary Smith <jaffacakemonster53@gmail.com> wrote:
Hi,
I have noticed that after a few minutes of becoming online, and randomly perhaps a couple of times every hour (??) tor uses 100 % processor on all cores for about 40/50 seconds.
I am curious what is tor doing internally to need so much power? There is normally isn't more than 4 mbits going through my relay, I noticed this a while back on htop before the December load increase and on previous versions so this has got to be an "internal thing". There is no log entry when this happens.
I do not think it is a bug I am just curious why it needs this much computational power,
Every hour, Tor downloads directory documents, creates diffs to recent consensuses, and compresses the documents (and diffs) using gzip, zstd, and lzma. This reduces client directory bandwidth, but costs CPU, RAM, and disk space. If anyone wants to disable directory document caching, they can set: DirPort 0 DirCache 0 T
If anyone wants to disable directory document caching, they can set: DirPort 0 DirCache 0
This results in the following log entry: [warn] DirCache is disabled and we are configured as a relay. This may disqualify us from becoming a guard in the future. That's a bit vague. What's that about? Will disabling the DirCache affect the Guard flag (today)?
On 6 Feb 2018, at 06:13, tor <tor@anondroid.com> wrote:
If anyone wants to disable directory document caching, they can set: DirPort 0 DirCache 0
This results in the following log entry:
[warn] DirCache is disabled and we are configured as a relay. This may disqualify us from becoming a guard in the future.
That's a bit vague. What's that about?
If you have the CPU, RAM, and disk space, you should leave these settings on.
Will disabling the DirCache affect the Guard flag (today)?
It will affect some client versions' choice of guards: https://trac.torproject.org/projects/tor/ticket/24312#comment:4 T
If you have the CPU, RAM, and disk space, you should leave these settings on.
It will affect some client versions' choice of guards: https://trac.torproject.org/projects/tor/ticket/24312#comment:4
I have guards that are bottle-necked by CPU, and I'm still exploring various options in response to DoS and extra load. It seems like "DirCache 0" isn't the best option in this case, since modern Tor Browser clients will not choose a guard with "DirCache 0". For now I will utilize other options that have been discussed here. Thanks for the info!
Every hour, Tor downloads directory documents, creates diffs to recent consensuses, and compresses the documents (and diffs) using gzip, zstd, and lzma.
Thanks for getting back to me. Except during the mentioned peaks, the relay only uses 5 - 6 % of available CPU power on a machine that is a dedicated relay so for now I will leave the settings alone. Thanks.
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Gary Smith -
teor -
tor