Maybe you can also attach strace to a running ATS process. From there you can see what threads are busy or blocked.
I like to trace on pread64 pwrite64 writev readv and network On Mon, Sep 9, 2019, 10:54 AM Jason Yang <[email protected]> wrote: > Hi community, > I am running an ATS cluster with debug workload (a replay of normal > workload with all headers removed) and I have noticed that a significant > portion (>20%) of cache misses are just tunneled through without being > written to disk (extracted using via header, and in my toy experiment, > every miss should be cached). I assume this happens because the aggregation > write buffer is full, so the some of the disk writes are dropped. > > I have tried to increase the the aggregation buffer from 4MB to 256MB when > I compile ATS, but it does not help. > > Besides my NVME disk throughput (> 1600MB/s for 1MB fragment > 80%read+20%write from FIO test) is way higher than what I observed during > the experiments, during which I rarely see over 200MB/s read+writing. > > Any suggestion on how I should tune ATS to gain better performance? Maybe > increase the number of cache threads per disk? Or maybe increase/reduce > fragment size? Or any suggestion on how to figure out the reason of dropped > disk writes? > Any thoughts are appreciated! > > > Best, > Jason > > >
