<<On Sat, 9 Mar 2013 11:27:32 -0500 (EST), Rick Macklem <rmack...@uoguelph.ca> said:
> around the highwater mark basically indicates this is working. If it wasn't > throwing away replies where the receipt has been ack'd at the TCP > level, the cache would grow very large, since they would only be > discarded after a loonnngg timeout (12hours unless you've changes > NFSRVCACHE_TCPTIMEOUT in sys/fs/nfs/nfs.h). That seems unreasonably large. > Well, the DRC will try to cache replies until the client's TCP layer > acknowledges receipt of the reply. It is hard to say how many replies > that is for a given TCP connection, since it is a function of the level > of concurrently (# of nfsiod threads in the FreeBSD client) > in the client. I'd guess it's somewhere between 1<->20? Nearly all our clients are Linux, so it's likely to be whatever Debian does by default. > Multiply that by the number of TCP connections from all clients and > you have about how big the server's DRC will be. (Some clients use > a single TCP connection for the client whereas others use a separate > TCP connection for each mount point.) The Debian client appears to use a single TCP connection for everything. So if I want to support 2,000 clients each with 20 requests in flight, that would suggest that I need a DRC size of 40,000, which my experience shows is not sufficient with even a much smaller number of clients. -GAWollman _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
