Re: datagram queue length

[Jonathan Ellis <jonathan@berkeleydata.net>]

linux-os (Dick Johnson) wrote:
>>I seem to be running into a limit of 64 queued datagrams.  This isn't a
>>data buffer size; varying the size of the datagram makes no difference
>>in the observed queue size.  If more datagrams are sent before some are
>>read, they are silently dropped.  (By "silently," I mean, "tcpdump
>>doesn't record these as dropped packets.")

> Your datagram receiver isn't keeping up with your datagram
> transmitter. If you increase the number of datagrams that are
> being queued, you will still encounter the same problem, but
> after more datagrams are stored.

Right -- except that my consumer is quite fast enough in the average 
case; it's only the worst case where it can't keep up.  Extending the 
queue would allow it to catch up with such bursts of activity without 
dropping requests.  The low- and mid- hanging fruit has already been 
picked as far as consumer optimization goes; anything remaining is quite 
high indeed.

> In your test code, you deliberately don't receive anything
> for 5 seconds. What do you expect?

I expected to demonstrate the problem. :)

-Jonathan