> From: Shawn Heisey [s...@elyograg.org] > >On 6/3/2013 3:33 PM, Greg Harris wrote: >> >> You have to be careful looking at the QTime's. They do not include garbage >> collection. I've run into issues where QTime is short (cause it was), it >> just happened that the query came in during a long garbage collection where >> everything was paused. So you can get into situations where once the 15 >> second GC is done everything performs as expected! I'd make sure and have an >> external querying tool and you can monitor GC times as well via JMX. > >The QTime value in the response is calculated using >System.currentTimeMillis(), so it should include the GC time, unless the >GC happens to hit just after the QTime is calculated but before the >final response with all the results is sent. If you are requesting a >lot of documents or you have very large documents where most/all of the >fields are stored, having long GCs hit during that particular moment >might actually be a common occurrence.
Can't a GC also kick in before the timer starts, resulting a short QTime but a long time from the point of view of the client? Believe I have seen that phenomenon in action. Mike O'Regan
