Shrinking cache 'roster_item_cache'

Tell me please what should I do to get with this issue?

2017-08-09 11:18:06.141 [error] <0.426.0> Shrinking cache 'roster_item_cache' (current size = 1003, max size = 1000, life time = 3600000, memory = 287280 bytes); you should increase maximum cache size if this message repeats too often
2017-08-09 11:18:19.501 [error] <0.426.0> Shrinking cache 'roster_item_cache' (current size = 1011, max size = 1000, life time = 3600000, memory = 289152 bytes); you should increase maximum cache size if this message repeats too often
2017-08-09 11:18:25.409 [error] <0.20056.62> CRASH REPORT Process <0.20056.62> with 0 neighbours exited with reason: {process_limit,{max_queue,1189}} in p1_server:terminate/7 line 864
2017-08-09 11:18:25.409 [error] <0.444.0> Supervisor ejabberd_c2s_sup had child undefined started with {ejabberd_c2s,start_link,undefined} at <0.20056.62> exit with reason {process_limit,{max_queue,1189}} in context child_terminated
2017-08-09 11:18:29.298 [error] <0.426.0> Shrinking cache 'roster_item_cache' (current size = 1032, max size = 1000, life time = 3600000, memory = 290960 bytes); you should increase maximum cache size if this message repeats too often
2017-08-09 11:18:42.622 [error] <0.426.0> Shrinking cache 'roster_item_cache' (current size = 1007, max size = 1000, life time = 3600000, memory = 275784 bytes); you should increase maximum cache size if this message repeats too often