Thanks, Mike. See comments below: 1) Will do. Good idea! 2) Good idea too. Not sure how to do that but I'll google and find out.
I'll get back with my findings. Thanks again! -JC On Wednesday, April 12, 2017 at 4:41:18 PM UTC-5, mikeb01 wrote: > > I'm not what is going on, but you could try eliminating a few things. > > 1) Is it a TCP protocol behaviour (e.g. slow start)? Test this by > implementing the same thing using UDP. > 2) Are your CPUs going to sleep? Test by locking the CPU frequency > scaling and/or setting the power management for the CPU to performance mode. > > Mike. > > On 13 April 2017 at 07:56, J Crawford <[email protected] <javascript:>> > wrote: > >> The SO question has the source codes of a simple server and client that >> demonstrate and isolate the problem. Basically I'm timing the latency of a >> ping-pong (client-server-client) message. I start by sending one message >> every 1 millisecond. I wait for 200k messages to be sent so that the >> HotSpot has a chance to optimize the code. Then I change my pause time from >> 1 millisecond to 30 seconds. For my surprise my write and read operation >> become considerably slower. >> >> I don't think it is a JIT/HotSpot problem. I was able to pinpoint the >> slower method to the native JNI calls to write (write0) and read. Even if I >> change the pause from 1 millisecond to 1 second, problem persists. >> >> I was able to observe that on MacOS and Linux. >> >> Does anyone here have a clue of what can be happening? >> >> Note that I'm disabling Nagle's Algorithm with setTcpNoDelay(true). >> >> SO question with code and output: >> http://stackoverflow.com/questions/43377600/socketchannel-why-if-i-write-msgs-quickly-the-latency-of-each-message-is-low-b >> >> Thanks! >> >> -JC >> >> -- >> You received this message because you are subscribed to the Google Groups >> "mechanical-sympathy" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > -- You received this message because you are subscribed to the Google Groups "mechanical-sympathy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
