Since I upgraded to ES 2.4.2 I have been noticing the master servers falling off and rejoining the cluster due to long GC . They are master only nodes with 16gb memory. I even increased the ES_HEAP_SIZE from 8g to 10g ( ES_HEAP_SIZE=10g ) but still does not help. The cluster has 22 data nodes and 3 master only nodes. Please help
[2017-02-14 02:06:17,113][WARN ][monitor.jvm ] [ElasticSearch-15] [gc][young][24516][88] duration [1s], collections [1]/[1.8s], total [1s]/[8.3s], memory [2.1gb]->[2.3gb]/[7.9gb], all_pools {[young] [6.4mb]->[1016.6kb]/[266.2mb]}{[survivor] [1.3mb]->[33.2mb]/[33.2mb]}{[old] [2.1gb]->[2.3gb]/[7.6gb]}
[2017-02-14 06:06:52,933][WARN ][monitor.jvm ] [ElasticSearch-15] [gc][old][38932][3] duration [12.9s], collections [1]/[13s], total [12.9s]/[13s], memory [7.5gb]->[3.4gb]/[7.9gb], all_pools {[young] [1.5mb]->[1.1mb]/[266.2mb]}{[survivor] [33.2mb]->[0b]/[33.2mb]}{[old] [7.4gb]->[3.4gb]/[7.6gb]}
[2017-02-14 08:06:24,741][WARN ][monitor.jvm ] [ElasticSearch-15] [gc][young][46101][253] duration [1.1s], collections [1]/[1.9s], total [1.1s]/[35.8s], memory [5.2gb]->[5.4gb]/[7.9gb], all_pools {[young] [33mb]->[2.1mb]/[266.2mb]}{[survivor] [1.5mb]->[33.2mb]/[33.2mb]}{[old] [5.2gb]->[5.4gb]/[7.6gb]}
[2017-02-14 08:06:42,841][WARN ][monitor.jvm ] [ElasticSearch-15] [gc][old][46107][4] duration [10.5s], collections [1]/[11.4s], total [10.5s]/[23.6s], memory [7.3gb]->[2.5gb]/[7.9gb], all_pools {[young] [853.7kb]->[6.8mb]/[266.2mb]}{[survivor