20 Apr 12, 06:28PM
No, it also requires disk access for logs, and calls fflush after every line. fflush isn't fsync though, and even in a datacenter with a dedicated storage server rather than disks right in the machines, I can't see how that could block for a whole second. Also, there's no measurable delay between writes before and after the spikes. Massive IO delays can of course happen, e.g. on the first access after some inactivity, but that's clearly not the case here.