#24782: Set a lower default MaxMemInQueues value
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Reporter: teor | Owner: ahf
Type: defect | Status: assigned
Priority: Medium | Milestone: Tor: 0.3.2.x-final
Component: Core Tor/Tor | Version:
Severity: Normal | Resolution:
Keywords: tor-relay, tor-ddos | Actual Points:
Parent ID: | Points: 0.5
Reviewer: | Sponsor:
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Comment (by dgoulet):
We could also explore the possibility for that value to be a moving target
at runtime. It is a bit more dicy and complicated but because Tor at
startup looks at the "Total memory" instead of the "Available memory" to
estimate that value, things can go badly quickly if 4/16 GB of RAM are
available which will make Tor use 12GB as a limit... and even with a
fairly good amount of swap, this is likely to be killed by the OOM of the
OS at some point.
On the flip side, a fast relay stuck with an estimation of 1GB or 2GB of
RAM that Tor can use at startup won't be "fast" for much long before the
OOM kicks in and start killing old circuits. It is difficult to tell what
a normal fast relay will endure in terms of RAM for Tor overtime but so
far of what I can tell with my relays, between 1 and 2 GB is usually what
I see (in non-DoS condition and non-Exit).
I do believe right now that the network is still fairly usable because we
have big Guards able to use 5, 10, 12GB of RAM right now... Unclear to me
if firing up the OOM more frequently would improve the situation but we
should be very careful at not making every relays using a "too low amount
of ram" :S.
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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/24782#comment:5>
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