Ceph » mgr

Description of problem¶

I have a Ceph cluster running 14.2.22 and have enabled the telegraf metrics. This cluster is working fine, and I am able to see the stats in Grafana.
I have a new Ceph cluster running 16.2.7 that I also enabled telegraf metrics. On this cluster, several of the metrics are not working because the value type changed from float to integer.


2021-12-27T19:53:35Z E! [outputs.influxdb] E! [outputs.influxdb] Failed to write metric (will be dropped: 400 Bad Request): partial write: field type conflict: input field "value" on measurement "ceph_daemon_stats" is type integer, already exists as type float dropped=686
2021-12-27T19:53:59Z E! [outputs.influxdb] E! [outputs.influxdb] Failed to write metric (will be dropped: 400 Bad Request): partial write: field type conflict: input field "value" on measurement "ceph_pool_stats" is type integer, already exists as type float dropped=1000


In Influxdb, once you have written a measurement it must always stay as that measurement type. You can change the measurement in the database, but you cannot use the old measurement type anymore.
https://docs.influxdata.com/influxdb/v1.7/troubleshooting/frequently-asked-questions/#can-i-change-a-fields-data-type

There should be an option to specify the measurement type in the telegraf config between int and float.

Environment¶

• ceph version string: ceph version 16.2.7 (dd0603118f56ab514f133c8d2e3adfc983942503) pacific (stable)
• Platform (OS/distro/release): Ubuntu 20.04
• Cluster details (nodes, monitors, OSDs): 3 MON/Mgr, 5 OSD
• Browser used (e.g.: Version 86.0.4240.198 (Official Build) (64-bit)):

How reproducible¶

Create a Ceph cluster running 14.2.22, and enable telegraf stats that send to an InfluxDB server. Verify that the stats can be viewed in Grafana.
Create a new Ceph cluster running 16.2.7 and enable telegraf stats to the same InfluxDB server.

Actual results¶

You will not see the daemon or pool stats in Grafana, and you will see the above log messages in the telegraf logs on the mgr.

Expected results¶

The metrics should be able to be processed for both Ceph versions.