On Wed, Oct 2, 2013 at 12:48 AM, Kenneth Gunn <[email protected]> wrote: > Hi! > > > My team is developing a service in node. We are experiencing high CPU > utilization and are attempting to profile, but are having a hard time > getting a sufficient picture of what’s going on. We have experience > profiling in various other environments, but this is our first crack at > node. > > > We've tried a few different tools (including nodetime.com, which has been > useful for some things), and have spent most of our time with the v8 > profiler. The main problem is that our viewable results only cover a small > portion of the program runtime. More than 80% of the time is spent in > libc.so, and that time isn't rolled up by function or caller in the node > program. Also, the C++ section, which I would expect to contain events in > the v8 interpreter itself, is empty. (Below, I'm including an abbreviated > output from the v8 tick processor.)
You need to have the binutils package installed. The tick processor uses `nm` to map addresses to symbol. Small nomenclature nit: V8 is a just-in-time compiler, not an interpreter. > We're aware that the v8 profiling output changes frequently, and we've > managed to figure out how to get the right tick processor version that > corresponds to the node version we are using. (Our steps are here: > https://gist.github.com/kennethgunn/6770664 ) We've seen very similar > results with versions of node ranging from v0.8.9 to v0.10.18. > > > Is libc actually responsible for 80+% of the CPU time? If so, how do we > roll that up to the the higher level code leading to those calls? Does it > sound like we're missing something here, or is there another set of tools we > should consider using? Your help is greatly appreciated! That's probably node.js sleeping in the epoll_wait() system call. Future versions of node.js will filter out such ticks but right now that's not possible, you have to keep your application busy when profiling. -- -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups "nodejs" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en --- You received this message because you are subscribed to the Google Groups "nodejs" 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/groups/opt_out.
