ceph/doc/cephfs/metrics.rst
Jos Collin f8f47852f3
doc: document metrics exported by CephFS
Fixes: https://tracker.ceph.com/issues/66173
Signed-off-by: Jos Collin <jcollin@redhat.com>
2024-05-27 14:42:56 +05:30

133 lines
3.9 KiB
ReStructuredText

.. _cephfs_metrics:
Metrics
=======
CephFS uses :ref:`Perf Counters` to track metrics. The counters can be labeled (:ref:`Labeled Perf Counters`).
Client Metrics
--------------
CephFS exports client metrics as :ref:`Labeled Perf Counters`, which could be used to monitor the client performance. CephFS exports the below client metrics.
.. list-table:: Client Metrics
:widths: 25 25 75
:header-rows: 1
* - 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
}
}
]