[ceph-users] Ceph Nautilous 14.2.22 slow OSD memory leak?

Dear Ceph folks, I am responsible for two Ceph clusters, running Nautilius 14.2.22 version, one with replication 3, and the other with EC 4+2. After around 400 days runing quietly and smoothly, recently the two clusters occured with similar problems: some of OSDs consume ca 18 GB while the memory target is setting at 2GB. What could wrong in the background? Does it mean any slow OSD memory leak issues with 14.2.22 which i do not know yet? I would be highly appreciated if some some provides any clues, ideas, comments ...... best regards, Samuel huxiaoyu@horebdata.cn