cluster node (async replication slave) high memory usage

We are seeing high memory usage on cluster member running as async replication slave node, whereas other cluster member's memory usage is normal.

– Cluster member asynchronous replication slave node

{{tprod-dba-test-sa-03:~$ top -n5 | grep mysql
32021 mysql 20 0 6161m 5.3g 115m S 3 67.4 562:46.43 massif-amd64-li
32021 mysql 20 0 6161m 5.3g 115m S 1 67.4 562:46.47 massif-amd64-li
32021 mysql 20 0 6161m 5.3g 115m S 10 67.4 562:46.77 massif-amd64-li
32021 mysql 20 0 6161m 5.3g 115m S 5 67.4 562:46.93 massif-amd64-li}}

— Cluster member normal node

{{itprod-dba-test-sa-02:~$ top -n5 | grep mysql
8707 mysql 20 0 2115m 1.4g 137m S 2 18.4 350:05.71 massif-amd64-li
8707 mysql 20 0 2115m 1.4g 137m S 3 18.4 350:05.79 massif-amd64-li
8707 mysql 20 0 2115m 1.4g 137m S 1 18.4 350:05.82 massif-amd64-li
8707 mysql 20 0 2115m 1.4g 137m S 1 18.4 350:05.84 massif-amd64-li
8707 mysql 20 0 2115m 1.4g 137m S 2 18.4 350:05.89 massif-amd64-li}}

I profiled memory usage of 2x nodes cluster using Valgrind massif tool:
https://www.percona.com/blog/2013/01/09/profiling-mysql-memory-usage-with-valgrind-massif/

ms_print outputs are attached:
1. massif_cluster_normal_node_.out
2. massif_cluster_asych_slave_node.out