# Performance drops when "collection occurred" appears in logs **URL:** \ **Category:** Elasticsearch\ **Created:** [April 13, 2011, 1:45pm UTC](https://discuss.elastic.co/t/performance-drops-when-collection-occurred-appears-in-logs/4229 "2011-04-13T13:45:15Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![byuva](https://avatars.discourse-cdn.com/v4/letter/b/b5ac83/32.png) [@byuva](https://discuss.elastic.co/u/byuva)\ **Post date:** [April 13, 2011, 1:45pm UTC](https://discuss.elastic.co/t/performance-drops-when-collection-occurred-appears-in-logs/4229/1 "2011-04-13T13:45:15Z")
I am running Master 0.16, (from around the end of March) and I've attached a portion of the logs which correspond to a large drop in performance. I have ES configured for 2GB MIN and MAX on a machine with 4GB (and based on my memory metrics the heap shouldn't be being pushed out of memory). I couldn't find the meaning of "collection occurred" but it seems to be at the heart of the issue: -brian [2011-04-13 00:32:50,583][INFO][monitor.jvm] [Exploding Man] [gc][ConcurrentMarkSweep][2013] took [12s]/[10.4m], reclaimed [-2.7E7b], leaving [1.9gb] used, max [2.1gb] [2011-04-13 00:33:00,585][INFO][monitor.jvm] [Exploding Man] [gc][ConcurrentMarkSweep][2014] took [10.3s]/[10.4m], reclaimed [-1.8E7b], leaving [1.9gb] used, max [2.1gb] [2011-04-13 00:33:12,599][INFO][monitor.jvm] [Exploding Man] [gc][ConcurrentMarkSweep][2015] took [11s]/[10.4m], reclaimed [-3.2E7b], leaving [1.9gb] used, max [2.1gb] [2011-04-13 00:33:24,602][INFO][monitor.jvm] [Exploding Man] [gc][ConcurrentMarkSweep][2016] took [11.8s]/[10.4m], reclaimed [-1.6E7b], leaving [1.9gb] used, max [2.1gb] [2011-04-13 00:34:09,309][INFO][monitor.jvm] [Exploding Man] [gc][ConcurrentMarkSweep][2021] took [10.2s]/[10.4m], reclaimed [-5437536b], leaving [1.9gb] used, max [2.1gb] [2011-04-13 00:34:52,712][INFO][monitor.jvm] [Exploding Man] [gc][ConcurrentMarkSweep] collection occurred, took [5.9s] [2011-04-13 00:35:18,143][INFO][monitor.jvm] [Exploding Man] [gc][ConcurrentMarkSweep] collection occurred, took [5.9s] [2011-04-13 00:35:43,561][INFO][monitor.jvm] [Exploding Man] [gc][ConcurrentMarkSweep] collection occurred, took [6.1s] [2011-04-13 00:36:10,158][INFO][monitor.jvm] [Exploding Man] [gc][ConcurrentMarkSweep] collection occurred, took [6.3s] [2011-04-13 00:36:35,503][INFO][monitor.jvm] [Exploding Man] [gc][ConcurrentMarkSweep] collection occurred, took [6s] [2011-04-13 00:37:00,803][INFO][monitor.jvm] [Exploding Man] [gc][ConcurrentMarkSweep] collection occurred, took [6s] [ ---
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [April 13, 2011, 6:47pm UTC](https://discuss.elastic.co/t/performance-drops-when-collection-occurred-appears-in-logs/4229/2 "2011-04-13T18:47:06Z")
Seems like there is strain on the memory usage, and you are hitting that 2gb wall, you either need more memory, or more servers. You can try and get a feeling of where memory is used using the node stats API. On Wednesday, April 13, 2011 at 4:45 PM, merrellb wrote: > I am running Master 0.16, (from around the end of March) and I've > attached a portion of the logs which correspond to a large drop in > performance. I have ES configured for 2GB MIN and MAX on a machine > with 4GB (and based on my memory metrics the heap shouldn't be being > pushed out of memory). I couldn't find the meaning of "collection > occurred" but it seems to be at the heart of the issue: > > -brian > > [2011-04-13 00:32:50,583][INFO][monitor.jvm] [Exploding > Man] [gc][ConcurrentMarkSweep][2013] took [12s]/[10.4m], reclaimed > [-2.7E7b], leaving [1.9gb] used, max [2.1gb] > [2011-04-13 00:33:00,585][INFO][monitor.jvm] [Exploding > Man] [gc][ConcurrentMarkSweep][2014] took [10.3s]/[10.4m], reclaimed > [-1.8E7b], leaving [1.9gb] used, max [2.1gb] > [2011-04-13 00:33:12,599][INFO][monitor.jvm] [Exploding > Man] [gc][ConcurrentMarkSweep][2015] took [11s]/[10.4m], reclaimed > [-3.2E7b], leaving [1.9gb] used, max [2.1gb] > [2011-04-13 00:33:24,602][INFO][monitor.jvm] [Exploding > Man] [gc][ConcurrentMarkSweep][2016] took [11.8s]/[10.4m], reclaimed > [-1.6E7b], leaving [1.9gb] used, max [2.1gb] > [2011-04-13 00:34:09,309][INFO][monitor.jvm] [Exploding > Man] [gc][ConcurrentMarkSweep][2021] took [10.2s]/[10.4m], reclaimed > [-5437536b], leaving [1.9gb] used, max [2.1gb] > [2011-04-13 00:34:52,712][INFO][monitor.jvm] [Exploding > Man] [gc][ConcurrentMarkSweep] collection occurred, took [5.9s] > [2011-04-13 00:35:18,143][INFO][monitor.jvm] [Exploding > Man] [gc][ConcurrentMarkSweep] collection occurred, took [5.9s] > [2011-04-13 00:35:43,561][INFO][monitor.jvm] [Exploding > Man] [gc][ConcurrentMarkSweep] collection occurred, took [6.1s] > [2011-04-13 00:36:10,158][INFO][monitor.jvm] [Exploding > Man] [gc][ConcurrentMarkSweep] collection occurred, took [6.3s] > [2011-04-13 00:36:35,503][INFO][monitor.jvm] [Exploding > Man] [gc][ConcurrentMarkSweep] collection occurred, took [6s] > [2011-04-13 00:37:00,803][INFO][monitor.jvm] [Exploding > Man] [gc][ConcurrentMarkSweep] collection occurred, took [6s] > [ ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 4:08am UTC](https://discuss.elastic.co/t/performance-drops-when-collection-occurred-appears-in-logs/4229/3 "2017-07-06T04:08:22Z")
Closed on July 6, 2017, 4:08am UTC