174 lines
6.6 KiB
Markdown
174 lines
6.6 KiB
Markdown
# DiskIO Input Plugin
|
|
|
|
This plugin gathers metrics about disk traffic and timing.
|
|
|
|
⭐ Telegraf v0.10.0
|
|
🏷️ system
|
|
💻 all
|
|
|
|
## Global configuration options <!-- @/docs/includes/plugin_config.md -->
|
|
|
|
In addition to the plugin-specific configuration settings, plugins support
|
|
additional global and plugin configuration settings. These settings are used to
|
|
modify metrics, tags, and field or create aliases and configure ordering, etc.
|
|
See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
|
|
|
|
[CONFIGURATION.md]: ../../../docs/CONFIGURATION.md#plugins
|
|
|
|
## Configuration
|
|
|
|
```toml @sample.conf
|
|
# Read metrics about disk IO by device
|
|
[[inputs.diskio]]
|
|
## Devices to collect stats for
|
|
## Wildcards are supported except for disk synonyms like '/dev/disk/by-id'.
|
|
## ex. devices = ["sda", "sdb", "vd*", "/dev/disk/by-id/nvme-eui.00123deadc0de123"]
|
|
# devices = ["*"]
|
|
|
|
## Skip gathering of the disk's serial numbers.
|
|
# skip_serial_number = true
|
|
|
|
## Device metadata tags to add on systems supporting it (Linux only)
|
|
## Use 'udevadm info -q property -n <device>' to get a list of properties.
|
|
## Note: Most, but not all, udev properties can be accessed this way. Properties
|
|
## that are currently inaccessible include DEVTYPE, DEVNAME, and DEVPATH.
|
|
# device_tags = ["ID_FS_TYPE", "ID_FS_USAGE"]
|
|
|
|
## Using the same metadata source as device_tags, you can also customize the
|
|
## name of the device via templates.
|
|
## The 'name_templates' parameter is a list of templates to try and apply to
|
|
## the device. The template may contain variables in the form of '$PROPERTY' or
|
|
## '${PROPERTY}'. The first template which does not contain any variables not
|
|
## present for the device is used as the device name tag.
|
|
## The typical use case is for LVM volumes, to get the VG/LV name instead of
|
|
## the near-meaningless DM-0 name.
|
|
# name_templates = ["$ID_FS_LABEL","$DM_VG_NAME/$DM_LV_NAME"]
|
|
```
|
|
|
|
### Docker container
|
|
|
|
To monitor the Docker engine host from within a container you will need to
|
|
mount the host's filesystem into the container and set the `HOST_PROC`
|
|
environment variable to the location of the `/proc` filesystem. Additionally,
|
|
it is required to use privileged mode to provide access to `/dev`.
|
|
|
|
If you are using the `device_tags` or `name_templates` options, you will need
|
|
to bind mount `/run/udev` into the container.
|
|
|
|
```shell
|
|
docker run --privileged -v /:/hostfs:ro -v /run/udev:/run/udev:ro -e HOST_PROC=/hostfs/proc telegraf
|
|
```
|
|
|
|
## Metrics
|
|
|
|
- diskio
|
|
- tags:
|
|
- name (device name)
|
|
- serial (device serial number)
|
|
- fields:
|
|
- reads (integer, counter)
|
|
- writes (integer, counter)
|
|
- read_bytes (integer, counter, bytes)
|
|
- write_bytes (integer, counter, bytes)
|
|
- read_time (integer, counter, milliseconds)
|
|
- write_time (integer, counter, milliseconds)
|
|
- io_time (integer, counter, milliseconds)
|
|
- weighted_io_time (integer, counter, milliseconds)
|
|
- iops_in_progress (integer, gauge)
|
|
- merged_reads (integer, counter)
|
|
- merged_writes (integer, counter)
|
|
- io_util (float64, gauge, percent)
|
|
- io_await (float64, gauge, milliseconds)
|
|
- io_svctm (float64, gauge, milliseconds)
|
|
|
|
On linux these values correspond to the values in [`/proc/diskstats`][1] and
|
|
[`/sys/block/<dev>/stat`][2].
|
|
|
|
[1]: https://www.kernel.org/doc/Documentation/ABI/testing/procfs-diskstats
|
|
|
|
[2]: https://www.kernel.org/doc/Documentation/block/stat.txt
|
|
|
|
### `reads` & `writes`
|
|
|
|
These values increment when an I/O request completes.
|
|
|
|
### `read_bytes` & `write_bytes`
|
|
|
|
These values count the number of bytes read from or written to this
|
|
block device.
|
|
|
|
### `read_time` & `write_time`
|
|
|
|
These values count the number of milliseconds that I/O requests have
|
|
waited on this block device. If there are multiple I/O requests waiting,
|
|
these values will increase at a rate greater than 1000/second; for
|
|
example, if 60 read requests wait for an average of 30 ms, the read_time
|
|
field will increase by 60*30 = 1800.
|
|
|
|
### `io_time`
|
|
|
|
This value counts the number of milliseconds during which the device has
|
|
had I/O requests queued.
|
|
|
|
### `weighted_io_time`
|
|
|
|
This value counts the number of milliseconds that I/O requests have waited
|
|
on this block device. If there are multiple I/O requests waiting, this
|
|
value will increase as the product of the number of milliseconds times the
|
|
number of requests waiting (see `read_time` above for an example).
|
|
|
|
### `iops_in_progress`
|
|
|
|
This value counts the number of I/O requests that have been issued to
|
|
the device driver but have not yet completed. It does not include I/O
|
|
requests that are in the queue but not yet issued to the device driver.
|
|
|
|
### `merged_reads` & `merged_writes`
|
|
|
|
Reads and writes which are adjacent to each other may be merged for
|
|
efficiency. Thus two 4K reads may become one 8K read before it is
|
|
ultimately handed to the disk, and so it will be counted (and queued)
|
|
as only one I/O. These fields lets you know how often this was done.
|
|
|
|
### `io_await`
|
|
|
|
The average time per I/O operation (ms)
|
|
|
|
### `io_svctm`
|
|
|
|
The service time per I/O operation, excluding wait time (ms)
|
|
|
|
### `io_util`
|
|
|
|
The percentage of time the disk was active (%)
|
|
|
|
## Sample Queries
|
|
|
|
### Calculate percent IO utilization per disk and host
|
|
|
|
```sql
|
|
SELECT non_negative_derivative(last("io_time"),1ms) FROM "diskio" WHERE time > now() - 30m GROUP BY "host","name",time(60s)
|
|
```
|
|
|
|
### Calculate average queue depth
|
|
|
|
`iops_in_progress` will give you an instantaneous value. This will give you the
|
|
average between polling intervals.
|
|
|
|
```sql
|
|
SELECT non_negative_derivative(last("weighted_io_time"),1ms) from "diskio" WHERE time > now() - 30m GROUP BY "host","name",time(60s)
|
|
```
|
|
|
|
## Example Output
|
|
|
|
```text
|
|
diskio,name=sda1 merged_reads=0i,reads=2353i,writes=10i,write_bytes=2117632i,write_time=49i,io_time=1271i,weighted_io_time=1350i,read_bytes=31350272i,read_time=1303i,iops_in_progress=0i,merged_writes=0i 1578326400000000000
|
|
diskio,name=centos/var_log reads=1063077i,writes=591025i,read_bytes=139325491712i,write_bytes=144233131520i,read_time=650221i,write_time=24368817i,io_time=852490i,weighted_io_time=25037394i,iops_in_progress=1i,merged_reads=0i,merged_writes=0i 1578326400000000000
|
|
diskio,name=sda write_time=49i,io_time=1317i,weighted_io_time=1404i,reads=2495i,read_time=1357i,write_bytes=2117632i,iops_in_progress=0i,merged_reads=0i,merged_writes=0i,writes=10i,read_bytes=38956544i 1578326400000000000
|
|
```
|
|
|
|
```text
|
|
diskio,name=sda io_await:0.3317307692307692,io_svctm:0.07692307692307693,io_util:0.5329780146568954 1578326400000000000
|
|
diskio,name=sda1 io_await:0.3317307692307692,io_svctm:0.07692307692307693,io_util:0.5329780146568954 1578326400000000000
|
|
diskio,name=sda2 io_await:0.3317307692307692,io_svctm:0.07692307692307693,io_util:0.5329780146568954 1578326400000000000
|
|
```
|