Ceph » RADOS

Implement rocksdb cache perf counter

Maybe we can use ceph daemon osd.$id perf dump and add rocksdb cache perf counter:

1. rocksdb cache full or not
2. how many omap keys it has
3. How many times it became full and flush?
4. any other important information

Version-Release number of selected component (if applicable):
Red Hat Ceph Storage 2.4

Right now perf dump covers the following:

  "rocksdb": {
        "rocksdb_get": 9798,
        "rocksdb_transaction": 518732,
        "rocksdb_get_latency": {
            "avgcount": 9798,
            "sum": 54.697089911
        },
        "rocksdb_submit_latency": {
            "avgcount": 505433,
            "sum": 15.398420482
        },
        "rocksdb_submit_sync_latency": {
            "avgcount": 13299,
            "sum": 12.566100383
        },
        "rocksdb_compact": 0,
        "rocksdb_compact_range": 0,
        "rocksdb_compact_queue_merge": 0,
        "rocksdb_compact_queue_len": 0
    },

Maybe we can add rocksdb cache here.

Downstream RFE - https://bugzilla.redhat.com/show_bug.cgi?id=1514504