This seems consistent with a GC pause. The size of the allocated heap would not necessarily be reduced to show a drop in memory usage after a GC. If the issue was due to the shared core not being available the Utilization would not have shown a spike.
On the standard runtime you don't have the ability to pass JVM options to tune the GC or use System.gc(), unfortunately. You'd be limited to performance tuning your code to reduce GCs, which is a fairly broad topic <https://www.google.ca/search?q=java+avoiding+garbage+collection>. On Tuesday, November 29, 2016 at 4:04:07 PM UTC-5, Thomas Baldauf wrote: > > CPU megacycles went up from 1300 to 20000 and down again, so this is > really suspicious. At the same time, memory usage was constantly at about > 215 MB and only went up slightly (a few MB) in the next minutes. Any ideas? > > > > Am Dienstag, 29. November 2016 19:55:31 UTC+1 schrieb Adam (Cloud Platform > Support): >> >> GC pauses could very well be the culprit. What do the Utilization and >> Memory Usage graphs look like at the time of the slow request? >> >> On Monday, November 28, 2016 at 1:21:20 AM UTC-5, Thomas Baldauf wrote: >>> >>> It would be hard to post my code here, because I'd have to include >>> HttpFilters and the whole DAO/Cache-layer. But there's really nothing going >>> on that's needing a lot of CPU resources. One thing I asked myself: could >>> it be GC occupying the process, because the frequency of such slow requests >>> is like every couple of hours? If so, is there anything we can do about it? >> >> -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/361899b6-1b45-4c3f-afed-0ec5841fe4ad%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
