Hi all Thanks for your reply.I do some investigation for much time.and I will post some logs of the 'top' and IO in a few days when the crash come again.
2016-03-08 10:45 GMT+08:00 Shawn Heisey <apa...@elyograg.org>: > On 3/7/2016 2:23 AM, Toke Eskildsen wrote: > > How does this relate to YouPeng reporting that the CPU usage increases? > > > > This is not a snark. YouPeng mentions kernel issues. It might very well > > be that IO is the real problem, but that it manifests in a non-intuitive > > way. Before memory-mapping it was easy: Just look at IO-Wait. Now I am > > not so sure. Can high kernel load (Sy% in *nix top) indicate that the IO > > system is struggling, even if IO-Wait is low? > > It might turn out to be not directly related to memory, you're right > about that. A very high query rate or particularly CPU-heavy queries or > analysis could cause high CPU usage even when memory is plentiful, but > in that situation I would expect high user percentage, not kernel. I'm > not completely sure what might cause high kernel usage if iowait is low, > but no specific information was given about iowait. I've seen iowait > percentages of 10% or less with problems clearly caused by iowait. > > With the available information (especially seeing 700GB of index data), > I believe that the "not enough memory" scenario is more likely than > anything else. If the OP replies and says they have plenty of memory, > then we can move on to the less common (IMHO) reasons for high CPU with > a large index. > > If the OS is one that reports load average, I am curious what the 5 > minute average is, and how many real (non-HT) CPU cores there are. > > Thanks, > Shawn > >
