Hi all
Following a couple of my earlier messages to the list (about alleged DDOS on my node) I started up a new relay only node with digitalocean (thanks to Roman Mamedov for the pointer).
In order to test their service I signed up for the minimal sized "droplet" (VPS) - 256Mb RAM, 1 core, 20Gb disk. Very quickly the VPS ramped up to over 1000 tor connections and a throughput of 25Mbit/s with a daily total traffic of 230 GiB. Absolutely astonishing when compared to the appalling service I was getting from my node at thrustvps. (After my complaints I was told "This is standard procedure for our clients, all nodes are on a 100mBits network, the node you are currently on shares that connection with 59 other virtual servers".) So no wonder the service was crap.
But this morning I noticed that the new server had stopped and tor says in it's log "Your computer is too slow to handle this many circuit creation requests! Please consider using the MaxAdvertisedBandwidth config option or choosing a m ore restricted exit policy."
I've never had the luxury of encountering this problem before, But clearly the network connectivity at digitalocean is not a limiting factor, and the resource of the VPS is. I monitored usage for the first day or so and top never showed any CPU bottleneck of high load averages, but memory was almost maxed out.
The manual entry for "MaxAdvertisedBandwidth" is not particularly clear because it does not specify whether the bytes|KB|MB|GB is per second or a maximum for some other period. And I do not have the experience to know what rate would best be set on a node with limited memory (though I will buy larger nodes iof this test works out over a longer period) but apparently unlimited network capacity. So my question is, what can colleages recommend as a suitable maximum rate which will allow my node to provide maximum utility to the tor network without falling over?
Many thanks in advance.
Mick ---------------------------------------------------------------------
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On Fri, 04 Jan 2013 13:36:20 +0000, mick wrote: ...
But this morning I noticed that the new server had stopped and tor says in it's log "Your computer is too slow to handle this many circuit creation requests! Please consider using the MaxAdvertisedBandwidth config option or choosing a m ore restricted exit policy."
I've never had the luxury of encountering this problem before,
I had. As it happened on a node with 50KB/s advertised bandwidth, I assume that it's not actually the bandwidth, but a (mostly) unrelated factor. My suspicion is that this happens when you happen to become a crucial position for a hidden service. (Or some rogue nodes are doing something strange.)
The problem is simply that the many circuit creation requests cause a lot of CPU to be used, and the node can't keep up with that. MaxAdvertisedBandwidth only very indirectly influences that.
...
The manual entry for "MaxAdvertisedBandwidth" is not particularly clear because it does not specify whether the bytes|KB|MB|GB is per second or a maximum for some other period.
It isn't; one may deduce from the units of the referenced BandwidthRate that MaxAdvertisedBandwidth is also per seconds.
...
So my question is, what can colleages recommend as a suitable maximum rate which will allow my node to provide maximum utility to the tor network without falling over?
As far as I can tell, tor is pretty much self-scaling in that regard, but I only have nodes with a relatively low BandwidthRate (500k).
Do you have an explicit BandwidthRate set?
Andreas
tor-relays@lists.torproject.org
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Andreas Krey -
mick