# Cluster running with default elastic configs facing slow searches with increase in heap **URL:** \ **Category:** Elasticsearch\ **Created:** [July 31, 2016, 2:07am UTC](https://discuss.elastic.co/t/cluster-running-with-default-elastic-configs-facing-slow-searches-with-increase-in-heap/56809 "2016-07-31T02:07:45Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![soodlikesjava](https://avatars.discourse-cdn.com/v4/letter/s/ee7513/32.png) [@soodlikesjava](https://discuss.elastic.co/u/soodlikesjava)\ **Post date:** [July 31, 2016, 2:07am UTC](https://discuss.elastic.co/t/cluster-running-with-default-elastic-configs-facing-slow-searches-with-increase-in-heap/56809/1 "2016-07-31T02:07:45Z")
Hi Team, We are running a cluster with 3 Masters and 12 data nodes which Network storage attached to them . All the instances are running on virtual machines . After running the cluster for 2 months where we keep only 30 days older indices and 20 indices per day are created which stores only 1 TB of data for 30 days . We know there are many factors which contribute to the heap usage such as file handles per index ,filter cache etc . We are not using field data cache . But with cluster running for 2 months having heap usage kept increasing to 78 GB which slows down the searches . When cluster is restarted heap is going down to 16 GB . Default elastic configs are used with mlock true . Can you please suggest if we need to change any settings or modify the GC configs . Currently we are using CMS collector. ---
**Author:** ![soodlikesjava](https://avatars.discourse-cdn.com/v4/letter/s/ee7513/32.png) [@soodlikesjava](https://discuss.elastic.co/u/soodlikesjava)\ **Post date:** [August 2, 2016, 3:28am UTC](https://discuss.elastic.co/t/cluster-running-with-default-elastic-configs-facing-slow-searches-with-increase-in-heap/56809/2 "2016-08-02T03:28:27Z")
Hi team please suggest on the above scenario. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 5, 2017, 10:31pm UTC](https://discuss.elastic.co/t/cluster-running-with-default-elastic-configs-facing-slow-searches-with-increase-in-heap/56809/3 "2017-07-05T22:31:00Z")