On Wed, 6 Sep 2006, Gleb Smirnoff wrote:
glebius 2006-09-06 13:56:35 UTC FreeBSD src repository Modified files: sys/netinet in_pcb.c tcp_subr.c tcp_timer.c tcp_var.h Log: o Backout rev. 1.125 of in_pcb.c. It appeared to behave extremely bad under high load. For example with 40k sockets and 25k tcptw entries, connect() syscall can run for seconds. Debugging showed that it iterates the cycle millions times and purges thousands of tcptw entries at a time. Besides practical unusability this change is architecturally wrong. First, in_pcblookup_local() is used in connect() and bind() syscalls. No stale entries purging shouldn't be done here. Second, it is a layering violation.
So you're returning to the behavior where the system chokes and stops all outbound TCP connections because everything is in the timewait state? There has to be a way to fix the problem without removing this heuristic entirely.
How did you run your tests?
o Return back the tcptw purging cycle to tcp_timer_2msl_tw(), that was removed in rev. 1.78 by rwatson. The commit log of this revision tells nothing about the reason cycle was removed. Now we need this cycle, since major cleaner of stale tcptw structures is removed.
Looks good, this is probably the reason for the code in in_pcb behaving so poorly. Did you test just this change alone to see if it solved the problem that you were seeing?
Mike "Silby" Silbersack _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/cvs-all To unsubscribe, send any mail to "[EMAIL PROTECTED]"
