Hi everybody
I observed two circuit bursts around July 19th. On a poor server Tor crashed, on a strong it didn't. The logs below are from the crashed one.
I'm on FreeBSD. To my mind the circuit burst exhausts the nmbclusters (not memory, Inact tells). Strong servers have more. How long is more enough ? On FreeBSD nmbclusters is a boot tunable.
The strong server took 140k circuits for several hours.
Is it worth thinking about a Tor setting like MaxCircuitsPerTime ? MaxAdvertisedBandwidth won't help directly.
1) Normal operation
kern.openfiles: 5516 Mem: 36M Active, 1288M Inact, 455M Wired, 1452K Cache, 425M Buf, 191M Free Swap: 3072M Total, 3072M Free USERNAME PRI NICE SIZE RES STATE TIME CPU COMMAND _tor 87 0 309M 283M RUN 125.7H 50.00% tor{tor} _tor 22 0 309M 283M uwait 167:32 3.96% tor{tor}
2) Last minute before crash:
kern.openfiles: 5467 Mem: 296M Active, 935M Inact, 692M Wired, 21M Cache, 425M Buf, 27M Free Swap: 3072M Total, 1592K Used, 3070M Free USERNAME PRI NICE SIZE RES STATE TIME CPU COMMAND _tor 85 0 465M 438M RUN 126.8H 43.99% tor{tor} _tor 33 0 465M 438M uwait 186:39 15.97% tor{tor}
3) Crashed:
kern.openfiles: 5455 Mem: 295M Active, 936M Inact, 699M Wired, 21M Cache, 425M Buf, 21M Free Swap: 3072M Total, 1592K Used, 3070M Free kernel: [zone: mbuf_cluster] kern.ipc.nmbclusters limit reached
sysctl kern.ipc.nmbclusters 126138
Heartbeat: Tor's uptime is 15 days 16:00 hours, with 1611 circuits Heartbeat: Tor's uptime is 15 days 17:00 hours, with 40471 circuits Heartbeat: Tor's uptime is 15 days 18:00 hours, with 88052 circuits Heartbeat: Tor's uptime is 15 days 19:00 hours, with 78444 circuits [warn] Your computer is too slow to handle this many circuit creation requests! Please consider using the MaxAdvertisedBandwidth config option or choosing a more restricted exit policy.