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Freya Gustavsson
bc62cb3709
Antora uses a dedicated folder structure which we need to adhere to for it to work as it should. Makefiles has moved to `doc/` root to simplify the approach needed with Antora and AsciiDoctor. Existing bundling of documentation with help of AsciiDoctor works as normal and does not interfere with the directory change. Signed-off-by: Freya Gustavsson <freya@venefilyn.se>
103 lines
3.2 KiB
Plaintext
103 lines
3.2 KiB
Plaintext
= cockpit.js: Metrics
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Metrics about the system can be retrieved from several sources using
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link:#cockpit-metrics[`+cockpit.metrics()+`] metrics channels. The
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metrics are made available as series data, and can be used with the
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link:#cockpit-series[`+cockpit.series()+`] and
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link:#cockpit-grid[`+cockpit.grid()+`] facilities.
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[[cockpit-metrics-function]]
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== cockpit.metrics()
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....
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metrics = cockpit.metrics(interval, options, cache)
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....
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Opens a new metrics channel. The data retrieved will be available in the
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link:#cockpit-metrics-series[`+metrics.series+`] series sink, and can be
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used together with link:#cockpit-grid[`+cockpit.grid()+`] objects.
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The `+interval+` is in milliseconds, and is the granularity of the
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series data retrieved. Any grids consuming the data must have the same
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interval.
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The `+cache+` argument is a cache identifier. If specified, then this
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metrics channel will share data with other metrics channels of the same
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identifier. Make sure to use a globally unique string.
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The `+options+` argument is either a javascript plain object, or an
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array of those. Each object can have the following fields.
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`+"metrics"+`::
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An array of full metric descriptions, as javascript objects. The
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specifics of these, and how to determine which ones to use, can
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unfortunately only be found in the low-level protocol documentation.
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This option is required.
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`+"source"+`::
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The source to use for real-time data. This is used by the `+follow+`
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method, see below. Set to `+"internal"+` to retrieve internal metrics
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read by the bridge. If set to `+"direct"+` or `+"pmcd"+` then data
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will be retrieved from https://pcp.io[PCP]if it is available. The
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default is `+"internal"+`.
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`+"archive_source"+`::
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The source to use for retrieving historical data. This is used by the
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`+fetch+` method, see below. Set to `+"pcp-archive"+` to retrieve data
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from PCP archives. The default is not to try to retrieve historical
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data.
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When the `+options+` argument is an array of javascript objects, then
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the metrics channel tries to use them in order until one succeeds. This
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way, you can prefer PCP as the source but fall back to internal metrics
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when PCP is not available, for example. The channel gives no indication
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which of the options has been used, and `+fetch+` and `+follow+` might
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use different entries from the list.
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[[cockpit-metrics-fetch]]
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== metrics.fetch()
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....
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metrics.fetch(beg, end)
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....
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Retrieve archived metrics data between `+beg+` and `+end+`. The
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arguments can either be numbers, in which case they are interval based
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offsets, or they can be javascript Date objects.
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[[cockpit-metrics-follow]]
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== metrics.follow()
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....
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metrics.follow()
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....
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Start retrieving live metrics data as it become available.
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[[cockpit-metrics-close]]
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== metrics.close()
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....
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metrics.close()
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....
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Stop the retrieval of metrics and release resources.
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[[cockpit-metrics-series]]
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== metrics.series
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The series sink where data retrieved data will be processed.
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[[cockpit-metrics-meta]]
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== metrics.meta
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The metrics meta data last received.
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[[cockpit-metrics-onchanged]]
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== metrics.onchanged
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....
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metrics.onchanged = function() { }
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....
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An event triggered when one of the properties on this metrics object
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changes.
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