Item ejection does not start immediately when mem_used > low_water mark

Here the mem_used is 20 MB more than low_water_mark on each node.
But no ejections have taken place. Not sure, if it should be immediate or not.

10.1.3.115
ep_num_active_non_resident: 0
ep_num_non_resident: 0
vb_active_num_non_resident: 0
vb_active_perc_mem_resident: 100
vb_pending_num_non_resident: 0
vb_pending_perc_mem_resident: 0
vb_replica_num_non_resident: 0
vb_replica_perc_mem_resident: 100

10.1.3.118
ep_num_active_non_resident: 0
ep_num_non_resident: 0
vb_active_num_non_resident: 0
vb_active_perc_mem_resident: 100
vb_pending_num_non_resident: 0
vb_pending_perc_mem_resident: 0
vb_replica_num_non_resident: 0
vb_replica_perc_mem_resident: 100

10.1.3.117
ep_num_active_non_resident: 0
ep_num_non_resident: 0
vb_active_num_non_resident: 0
vb_active_perc_mem_resident: 100
vb_pending_num_non_resident: 0
vb_pending_perc_mem_resident: 0
vb_replica_num_non_resident: 0
vb_replica_perc_mem_resident: 100

10.1.3.116
ep_num_active_non_resident: 0
ep_num_non_resident: 0
vb_active_num_non_resident: 0
vb_active_perc_mem_resident: 100
vb_pending_num_non_resident: 0
vb_pending_perc_mem_resident: 0
vb_replica_num_non_resident: 0
vb_replica_perc_mem_resident: 100

10.1.3.114
ep_num_active_non_resident: 0
ep_num_non_resident: 0
vb_active_num_non_resident: 0
vb_active_perc_mem_resident: 100
vb_pending_num_non_resident: 0
vb_pending_perc_mem_resident: 0
vb_replica_num_non_resident: 0
vb_replica_perc_mem_resident: 100

10.1.3.116
ep_kv_size: 560380696
ep_max_data_size: 1435500544
ep_mem_high_wat: 1076625408
ep_mem_low_wat: 861300326
ep_oom_errors: 0
ep_overhead: 137349056
ep_tmp_oom_errors: 0
ep_value_size: 450308980
mem_used: 885961039
tcmalloc_current_thread_cache_bytes: 2995984
tcmalloc_max_thread_cache_bytes: 4194304
tcmalloc_unmapped_bytes: 0
total_allocated_bytes: 872607224
total_fragmentation_bytes: 14127624
total_free_bytes: 360448
total_heap_bytes: 887095296

10.1.3.118
ep_kv_size: 557531381
ep_max_data_size: 1435500544
ep_mem_high_wat: 1076625408
ep_mem_low_wat: 861300326
ep_oom_errors: 0
ep_overhead: 136650872
ep_tmp_oom_errors: 0
ep_value_size: 448022155
mem_used: 882356000
tcmalloc_current_thread_cache_bytes: 3505600
tcmalloc_max_thread_cache_bytes: 4194304
tcmalloc_unmapped_bytes: 0
total_allocated_bytes: 868432488
total_fragmentation_bytes: 14697880
total_free_bytes: 819200
total_heap_bytes: 883949568

10.1.3.114
ep_kv_size: 561246455
ep_max_data_size: 1435500544
ep_mem_high_wat: 1076625408
ep_mem_low_wat: 861300326
ep_oom_errors: 0
ep_overhead: 137545832
ep_tmp_oom_errors: 0
ep_value_size: 451010409
mem_used: 889071939
tcmalloc_current_thread_cache_bytes: 2748920
tcmalloc_max_thread_cache_bytes: 4194304
tcmalloc_unmapped_bytes: 0
total_allocated_bytes: 875145616
total_fragmentation_bytes: 16062064
total_free_bytes: 184631296
total_heap_bytes: 1075838976

10.1.3.117
ep_kv_size: 560965619
ep_max_data_size: 1435500544
ep_mem_high_wat: 1076625408
ep_mem_low_wat: 861300326
ep_oom_errors: 0
ep_overhead: 137477384
ep_tmp_oom_errors: 0
ep_value_size: 450779854
mem_used: 886943905
tcmalloc_current_thread_cache_bytes: 3204848
tcmalloc_max_thread_cache_bytes: 4194304
tcmalloc_unmapped_bytes: 0
total_allocated_bytes: 873377624
total_fragmentation_bytes: 14340264
total_free_bytes: 425984
total_heap_bytes: 888143872

10.1.3.115
ep_kv_size: 560614313
ep_max_data_size: 1435500544
ep_mem_high_wat: 1076625408
ep_mem_low_wat: 861300326
ep_oom_errors: 0
ep_overhead: 137398360
ep_tmp_oom_errors: 0
ep_value_size: 450500736
mem_used: 886313269
tcmalloc_current_thread_cache_bytes: 3107376
tcmalloc_max_thread_cache_bytes: 4194304
tcmalloc_unmapped_bytes: 0
total_allocated_bytes: 872924120
total_fragmentation_bytes: 14162984
total_free_bytes: 8192
total_heap_bytes: 887095296

10.1.3.117
ep_num_eject_failures: 0
ep_num_eject_replicas: 0
ep_num_value_ejects: 0
rejected_conns: 0
vb_active_eject: 0
vb_active_ops_reject: 0
vb_pending_eject: 0
vb_pending_ops_reject: 0
vb_replica_eject: 0
vb_replica_ops_reject: 0

10.1.3.114
ep_num_eject_failures: 0
ep_num_eject_replicas: 0
ep_num_value_ejects: 0
rejected_conns: 0
vb_active_eject: 0
vb_active_ops_reject: 0
vb_pending_eject: 0
vb_pending_ops_reject: 0
vb_replica_eject: 0
vb_replica_ops_reject: 0

10.1.3.116
ep_num_eject_failures: 0
ep_num_eject_replicas: 0
ep_num_value_ejects: 0
rejected_conns: 0
vb_active_eject: 0
vb_active_ops_reject: 0
vb_pending_eject: 0
vb_pending_ops_reject: 0
vb_replica_eject: 0
vb_replica_ops_reject: 0

10.1.3.118
ep_num_eject_failures: 0
ep_num_eject_replicas: 0
ep_num_value_ejects: 0
rejected_conns: 0
vb_active_eject: 0
vb_active_ops_reject: 0
vb_pending_eject: 0
vb_pending_ops_reject: 0
vb_replica_eject: 0
vb_replica_ops_reject: 0

10.1.3.115
ep_num_eject_failures: 0
ep_num_eject_replicas: 0
ep_num_value_ejects: 0
rejected_conns: 0
vb_active_eject: 0
vb_active_ops_reject: 0
vb_pending_eject: 0
vb_pending_ops_reject: 0
vb_replica_eject: 0
vb_replica_ops_reject: 0