Lately I have seen a couple of incidents where the number of connections suddenly goes up to over 3000, traffic increases heavily, CPU usage goes well over 150% (out of possible 200). Traffic can go up to between 500 and 1000 KB/sec for long periods of time. Sometimes it seems that my relay just can't take it anymore. In the log, the ratio of TAP handshakes goes wild, and I get clock jump warnings. My clock does not jump. This is Tor hanging while allocating memory.
My very cheap home router couldn't handle many connections and crashed often. I solved the issue by disabling Hidden Services and now number of connections is very low and everything is smooth. (But I have just bought a new home router so I'll allow HS soon.) The magic configuration line is:
HidServDirectoryV2 0
Best regards, Ognyan Kulev