This plugin collects CPU statistics and device I/O statistics based on iostat command tool which is available in every distribution of Linux.
Used for monitoring system input/output device loading by observing the time the devices are active in relation to their average transfer rates.
The intention is that data will be collected, aggregated and fed into graphing and analysis plugin that can be used to change system configuration to better balance the input/output load between physical disks.
This plugin is used in the [Snap framework] (http://github.com/intelsdi-x/snap).
In order to use this plugin you need "iostat" to be installed on a Linux target host.
- Linux OS
- [sysstat package] (#installation)
- sysstat 10.2 or greater
- golang 1.6+ (needed only for building)
The iostat command-line tool is part of the sysstat package available under the GNU General Public License.
To install sysstat package from the official repositories simply use:
- For Ubuntu, Debian:
sudo apt-get install sysstat - For CentOS, Fedora:
sudo yum install sysstat
You can get the pre-built binaries for your OS and architecture from the plugin's GitHub Releases page. Download the plugin from the latest release and load it into snapteld (/opt/snap/plugins is the default location for Snap packages).
Fork https://github.com/intelsdi-x/snap-plugin-collector-iostat
Clone repo into $GOPATH/src/github.com/intelsdi-x/:
$ git clone https://github.com/<yourGithubID>/snap-plugin-collector-iostat.git
Build the Snap iostat plugin by running make within the cloned repo:
$ make
This builds the plugin in ./build/
- Set up the Snap framework
- Load the plugin and create a task, see example in Examples.
By default iostat executable binary are searched in the directories named by the PATH environment.
Customize path to iostat executable is also possible by setting environment variable export SNAP_IOSTAT_PATH=/path/to/iostat/bin
To learn more about this plugin and iostat tool, visit:
- [linux iostat tool] (http://linux.die.net/man/1/iostat)
- Snap iostat unit test
- Snap iostat examples
This plugin has the ability to gather the following metrics:
- CPU statistic
Metric namespace prefix: /intel/iostat/avg-cpu/
| Namespace | Description |
|---|---|
| %user | The percentage of CPU utilization that occurred while executing at the user level (the application usage) |
| %nice | The percentage of CPU utilization that occurred while executing at the user level with nice priority |
| %system | The percentage of CPU utilization that occurred while executing at the system level (the kernel usage) |
| %iowait | The percentage of time that the CPU or CPUs were idle during which the system had an outstanding disk I/O request |
| %steal | The percentage of time spent in involuntary wait by the virtual CPU or CPUs while the hypervisor was servicing another virtual processor |
| %idle | The percentage of time that the CPU or CPUs were idle and the systems did not have an outstanding disk I/O request |
- Device statistics
Metric namespace prefix: /intel/iostat/device/{disk_or_partition}
| Name | Description |
|---|---|
| rrqm_per_sec | The number of read requests merged per second queued to the device |
| wrqm_per_sec | The number of write requests merged per second queued to the device |
| r_per_sec | The number of read requests issued to the device per second |
| w_per_sec | The number of write requests issued to the device per second |
| rkB_per_sec | The number of kilobytes read from the device per second |
| wkB_per_sec | The number of kilobytes written to the device per second |
| avgrq-sz | The average size (in sectors) of the requests issued to the device |
| avgqu-sz | The average queue length of the requests issued to the device |
| await | The average time (milliseconds) for I/O requests issued to the device to be served This includes the time spent by the requests in queue and the time spent servicing them |
| r_await | The average time (in milliseconds) for read requests issued to the device to be served which includes the time spent by the requests in queue and the time spent servicing them |
| w_await | The average time (in milliseconds) for write requests issued to the device to be served which includes the time spent by the requests in queue and the time spent servicing them |
| svctm | The average service time (in milliseconds) for I/O requests issued to the device - Warning! Do not trust this field; it will be removed in a future version of sysstat |
| %util | Percentage of CPU time during which I/O requests were issued to the device (bandwidth utilization for the device); device saturation occurs when this values is close to 100% |
Notes:
- The total number of read and write requests issued to the device per second equals the number of transaction per second
- tps=r_per_sec+w_per_sec
- The metrics are sampled over 1 second
- If would like the results since boot you can set the config option
ReportSinceBoottotrue(see the sample task below)
Example running iostat collector and writing data to file.
Ensure Snap daemon is running:
- initd:
service snap-telemetry start - systemd:
systemctl start snap-telemetry - command line:
snapteld -l 1 -t 0 &
Download and load Snap plugins:
$ wget http://snap.ci.snap-telemetry.io/plugins/snap-plugin-collector-iostat/latest/linux/x86_64/snap-plugin-collector-iostat
$ wget http://snap.ci.snap-telemetry.io/plugins/snap-plugin-publisher-file/latest/linux/x86_64/snap-plugin-publisher-file
$ chmod 755 snap-plugin-*
$ snaptel plugin load snap-plugin-collector-iostat
$ snaptel plugin load snap-plugin-publisher-file
See all available metrics:
$ snaptel metric list
Download an example task file and load it:
$ curl -sfLO https://raw.githubusercontent.com/intelsdi-x/snap-plugin-collector-iostat/master/examples/tasks/iostat-file.json
$ snaptel task create -t iostat-file.json
Using task manifest to create task
Task created
ID: 02dd7ff4-8106-47e9-8b86-70067cd0a850
Name: Task-02dd7ff4-8106-47e9-8b86-70067cd0a850
State: Running
This data is published to a file /tmp/published_iostat per task specification
See realtime output from snaptel task watch <task_id> (CTRL+C to exit)
$ snaptel task watch 02dd7ff4-8106-47e9-8b86-70067cd0a850
Watching Task (02dd7ff4-8106-47e9-8b86-70067cd0a850):
NAMESPACE DATA TIMESTAMP SOURCE
/intel/iostat/avg-cpu/%idle 97.62 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/avg-cpu/%iowait 1.13 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/avg-cpu/%nice 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/avg-cpu/%steal 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/avg-cpu/%system 0.5 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/avg-cpu/%user 0.75 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/ALL/%util 1.69 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/ALL/r_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/ALL/rkB_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/ALL/rrqm_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/ALL/w_per_sec 133 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/ALL/wkB_per_sec 50672 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/ALL/wrqm_per_sec 326 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sda1/%util 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sda1/r_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sda1/rkB_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sda1/rrqm_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sda1/w_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sda1/wkB_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sda1/wrqm_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb/%util 6.8 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb/r_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb/rkB_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb/rrqm_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb/w_per_sec 68 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb/wkB_per_sec 25336 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb/wrqm_per_sec 163 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb1/%util 6.7 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb1/r_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb1/rkB_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb1/rrqm_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb1/w_per_sec 65 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb1/wkB_per_sec 25336 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb1/wrqm_per_sec 163 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb2/%util 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb2/r_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb2/rkB_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb2/rrqm_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb2/w_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb2/wkB_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
/intel/iostat/device/sdb2/wrqm_per_sec 0 2015-12-01 05:39:57.79589855 -0500 EST gklab-108-109-110-111
Stop task:
$ snaptel task stop 02dd7ff4-8106-47e9-8b86-70067cd0a850
Task stopped:
ID: 02dd7ff4-8106-47e9-8b86-70067cd0a850
Expectation of numeric string with a dot as decimal separator.
For another decimal mark, the following error will occur: Common error: invalid metric value strconv.ParseFloat: parsing "0,00": invalid syntax.
To resolve that, the locale numeric configuration (LC_NUMERIC) needs to be changed to set dot as decimal separator.
As we launch this plugin, we do not have any outstanding requirements for the next release. If you have a feature request, please add it as an issue and/or submit a pull request.
This repository is one of many plugins in Snap, a powerful telemetry framework. See the full project at http://github.com/intelsdi-x/snap
To reach out to other users, head to the main framework or visit Slack.
We love contributions!
There's more than one way to give back, from examples to blogs to code updates. See our recommended process in CONTRIBUTING.md.
Snap, along with this plugin, is an Open Source software released under the Apache 2.0 License.
- Author: Izabella Raulin
And thank you! Your contribution, through code and participation, is incredibly important to us.