Metrics
CephFS uses Perf counters to track metrics. The counters can be labeled (Labeled Perf Counters).
Client Metrics
CephFS exports client metrics as Labeled Perf Counters, which could be used to monitor the client performance. CephFS exports the below client metrics.
Name |
Type |
Description |
---|---|---|
num_clients |
Gauge |
Number of client sessions |
cap_hits |
Gauge |
Percentage of file capability hits over total number of caps |
cap_miss |
Gauge |
Percentage of file capability misses over total number of caps |
avg_read_latency |
Gauge |
Mean value of the read latencies |
avg_write_latency |
Gauge |
Mean value of the write latencies |
avg_metadata_latency |
Gauge |
Mean value of the metadata latencies |
dentry_lease_hits |
Gauge |
Percentage of dentry lease hits handed out over the total dentry lease requests |
dentry_lease_miss |
Gauge |
Percentage of dentry lease misses handed out over the total dentry lease requests |
opened_files |
Gauge |
Number of opened files |
opened_inodes |
Gauge |
Number of opened inodes |
pinned_icaps |
Gauge |
Number of pinned Inode Caps |
total_inodes |
Gauge |
Total number of Inodes |
total_read_ops |
Gauge |
Total number of read operations generated by all process |
total_read_size |
Gauge |
Number of bytes read in input/output operations generated by all process |
total_write_ops |
Gauge |
Total number of write operations generated by all process |
total_write_size |
Gauge |
Number of bytes written in input/output operations generated by all processes |
Getting Metrics
The metrics could be scraped from the MDS admin socket as well as using the tell interface. The mds_client_metrics-<fsname>
section in the output of counter dump
command displays the metrics for each client as shown below:
"mds_client_metrics": [
{
"labels": {
"fs_name": "<fsname>",
"id": "14213"
},
"counters": {
"num_clients": 2
}
}
],
"mds_client_metrics-<fsname>": [
{
"labels": {
"client": "client.0",
"rank": "0"
},
"counters": {
"cap_hits": 5149,
"cap_miss": 1,
"avg_read_latency": 0.000000000,
"avg_write_latency": 0.000000000,
"avg_metadata_latency": 0.000000000,
"dentry_lease_hits": 0,
"dentry_lease_miss": 0,
"opened_files": 1,
"opened_inodes": 2,
"pinned_icaps": 2,
"total_inodes": 2,
"total_read_ops": 0,
"total_read_size": 0,
"total_write_ops": 4836,
"total_write_size": 633864192
}
},
{
"labels": {
"client": "client.1",
"rank": "0"
},
"counters": {
"cap_hits": 3375,
"cap_miss": 8,
"avg_read_latency": 0.000000000,
"avg_write_latency": 0.000000000,
"avg_metadata_latency": 0.000000000,
"dentry_lease_hits": 0,
"dentry_lease_miss": 0,
"opened_files": 1,
"opened_inodes": 2,
"pinned_icaps": 2,
"total_inodes": 2,
"total_read_ops": 0,
"total_read_size": 0,
"total_write_ops": 3169,
"total_write_size": 415367168
}
}
]