зеркало из https://github.com/mozilla/gecko-dev.git
Bug 939866 - Add Services docs to Sphinx; r=rnewman
DONTBUILD (NPOTB) --HG-- extra : rebase_source : 5e4125ab7faa5493a10db903cf685ee1760f79ec
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Gregory Szorc
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Коммит
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======================
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Data Reporting Service
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======================
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This directory contains files related to data collection and reporting
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within Gecko applications.
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The important files in this directory are:
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DataReportingService.js
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An XPCOM service that coordinates collection and reporting of data.
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policy.jsm
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A module containing the logic for coordinating and driving collection
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and upload of data.
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sessions.jsm
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Records Gecko application session history. This is loaded as part of
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the XPCOM service because it needs to capture state from very early in
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the application lifecycle. Bug 841561 tracks implementing this in C++.
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There is other code in the tree that collects and uploads data. The
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original intent of this directory and XPCOM service was to serve as a
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focal point for the coordination of all this activity so that it could
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all be done consistently and properly. This vision may or may not be fully
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realized.
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@ -0,0 +1,28 @@
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.. _data_reporting_service:
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======================
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Data Reporting Service
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======================
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``/services/datareporting`` contains files related to an XPCOM service
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that collects and reports data within Gecko applications.
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The important files in this directory are:
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DataReportingService.js
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An XPCOM service that coordinates collection and reporting of data.
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policy.jsm
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A module containing the logic for coordinating and driving collection
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and upload of data.
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||||
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sessions.jsm
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Records Gecko application session history. This is loaded as part of
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the XPCOM service because it needs to capture state from very early in
|
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the application lifecycle. Bug 841561 tracks implementing this in C++.
|
||||
|
||||
There is other code in the tree that collects and uploads data. The
|
||||
original intent of this directory and XPCOM service was to serve as a
|
||||
focal point for the coordination of all this activity so that it could
|
||||
all be done consistently and properly. This vision may or may not be fully
|
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realized.
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@ -0,0 +1,250 @@
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.. _firefox_health_report:
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=====================
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Firefox Health Report
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=====================
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``/services/healthreport`` contains the implementation of the
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``Firefox Health Report`` (FHR).
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Firefox Health Report is a background service that collects application
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metrics and periodically submits them to a central server. The core
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parts of the service are implemented in this directory. However, the
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actual XPCOM service is implemented in the
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:ref:`data_reporting_service`.
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The core types can actually be instantiated multiple times and used to
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power multiple data submission services within a single Gecko
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application. In other words, everything in this directory is effectively
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a reusable library. However, the terminology and some of the features
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are very specific to what the Firefox Health Report feature requires.
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Architecture
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============
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``healthreporter.jsm`` contains the main interface for FHR, the
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``HealthReporter`` type. An instance of this is created by the
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:ref:`data_reporting_service`.
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``providers.jsm`` contains numerous ``Metrics.Provider`` and
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``Metrics.Measurement`` used for collecting application metrics. If you
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are looking for the FHR probes, this is where they are.
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Storage
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-------
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Firefox Health Report stores data in 3 locations:
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* Metrics measurements and provider state is stored in a SQLite database
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(via ``Metrics.Storage``).
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* Service state (such as the IDs of documents uploaded) is stored in a
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JSON file on disk (via OS.File).
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* Lesser state and run-time options are stored in preferences.
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Preferences
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-----------
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Preferences controlling behavior of Firefox Health Report live in the
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``datareporting.healthreport.*`` branch.
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Service and Data Control
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^^^^^^^^^^^^^^^^^^^^^^^^
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The follow preferences control behavior of the service and data upload.
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service.enabled
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Controls whether the entire health report service runs. The overall
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service performs data collection, storing, and submission.
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This is the primary kill switch for Firefox Health Report
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outside of the build system variable. i.e. if you are using an
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official Firefox build and wish to disable FHR, this is what you
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should set to false to prevent FHR from not only submitting but
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also collecting data.
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uploadEnabled
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Whether uploading of data is enabled. This is the preference the
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checkbox in the preferences UI reflects. If this is
|
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disabled, FHR still collects data - it just doesn't upload it.
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service.loadDelayMsec
|
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How long (in milliseconds) after initial application start should FHR
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wait before initializing.
|
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|
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FHR may initialize sooner than this if the FHR service is requested.
|
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This will happen if e.g. the user goes to ``about:healthreport``.
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service.loadDelayFirstRunMsec
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How long (in milliseconds) FHR should wait to initialize on first
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application run.
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FHR waits longer than normal to initialize on first application run
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because first-time initialization can use a lot of I/O to initialize
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the SQLite database and this I/O should not interfere with the
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first-run user experience.
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documentServerURI
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The URI of a Bagheera server that FHR should interface with for
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submitting documents.
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You typically do not need to change this.
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documentServerNamespace
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The namespace on the document server FHR should upload documents to.
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You typically do not need to change this.
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infoURL
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The URL of a page containing more info about FHR, it's privacy
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policy, etc.
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about.reportUrl
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The URL to load in ``about:healthreport``.
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service.providerCategories
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A comma-delimited list of category manager categories that contain
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registered ``Metrics.Provider`` records. Read below for how provider
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registration works.
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If the entire service is disabled, you lose data collection. This means
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that **local** data analysis won't be available because there is no data
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to analyze! Keep in mind that Firefox Health Report can be useful even
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if it's not submitting data to remote servers!
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Logging
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^^^^^^^
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The following preferences allow you to control the logging behavior of
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Firefox Health Report.
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|
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logging.consoleEnabled
|
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Whether to write log messages to the web console. This is true by
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default.
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|
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logging.consoleLevel
|
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The minimum log level FHR messages must have to be written to the
|
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web console. By default, only FHR warnings or errors will be written
|
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to the web console. During normal/expected operation, no messages of
|
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this type should be produced.
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logging.dumpEnabled
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Whether to write log messages via ``dump()``. If true, FHR will write
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messages to stdout/stderr.
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This is typically only enabled when developing FHR.
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||||
logging.dumpLevel
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The minimum log level messages must have to be written via
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``dump()``.
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State
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^^^^^
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currentDaySubmissionFailureCount
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How many submission failures the client has encountered while
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attempting to upload the most recent document.
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lastDataSubmissionFailureTime
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The time of the last failed document upload.
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||||
|
||||
lastDataSubmissionRequestedTime
|
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The time of the last document upload attempt.
|
||||
|
||||
lastDataSubmissionSuccessfulTime
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The time of the last successful document upload.
|
||||
|
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nextDataSubmissionTime
|
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The time the next data submission is scheduled for. FHR will not
|
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attempt to upload a new document before this time.
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pendingDeleteRemoteData
|
||||
Whether the client currently has a pending request to delete remote
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||||
data. If true, the client will attempt to delete all remote data
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||||
before an upload is performed.
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FHR stores various state in preferences.
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||||
|
||||
Registering Providers
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||||
=====================
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||||
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||||
Firefox Health Report providers are registered via the category manager.
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||||
See ``HealthReportComponents.manifest`` for providers defined in this
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directory.
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||||
|
||||
Essentially, the category manager receives the name of a JS type and the
|
||||
URI of a JSM to import that exports this symbol. At run-time, the
|
||||
providers registered in the category manager are instantiated.
|
||||
|
||||
Providers are registered via the category manager to make registration
|
||||
simple and less prone to errors. Any XPCOM component can create a
|
||||
category manager entry. Therefore, new data providers can be added
|
||||
without having to touch core Firefox Health Report code. Additionally,
|
||||
category manager registration means providers are more likely to be
|
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registered on FHR's terms, when it wants. If providers were registered
|
||||
in code at application run-time, there would be the risk of other
|
||||
components prematurely instantiating FHR (causing a performance hit if
|
||||
performed at an inopportune time) or semi-complicated code around
|
||||
observers or listeners. Category manager entries are only 1 line per
|
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provider and leave FHR in control: they are simple and safe.
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Document Generation and Lifecycle
|
||||
=================================
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FHR will attempt to submit a JSON document containing data every 24 wall
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clock hours.
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||||
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||||
At upload time, FHR will query the database for **all** information from
|
||||
the last 180 days and assemble this data into a JSON document. We
|
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attempt to upload this JSON document with a client-generated UUID to the
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configured server.
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||||
Before we attempt upload, the generated UUID is stored in the JSON state
|
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file on local disk. At this point, the client assumes the document with
|
||||
that UUID has been successfully stored on the server.
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|
||||
If the client is aware of other document UUIDs that presumably exist on
|
||||
the server, those UUIDs are sent with the upload request so the client
|
||||
can request those UUIDs be deleted. This helps ensure that each client
|
||||
only has 1 document/UUID on the server at any one time.
|
||||
|
||||
Importance of Persisting UUIDs
|
||||
------------------------------
|
||||
|
||||
The choices of how, where, and when document UUIDs are stored and updated
|
||||
are very important. One should not attempt to change things unless she
|
||||
has a very detailed understanding of why things are the way they are.
|
||||
|
||||
The client is purposefully very conservative about forgetting about
|
||||
generated UUIDs. In other words, once a UUID is generated, the client
|
||||
deliberately holds on to that UUID until it's very confident that UUID
|
||||
is no longer stored on the server. The reason we do this is because
|
||||
*orphaned* documents/UUIDs on the server can lead to faulty analysis,
|
||||
such as over-reporting the number of Firefox installs that stop being
|
||||
used.
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||||
|
||||
When uploading a new UUID, we update the state and save the state file
|
||||
to disk *before* an upload attempt because if the upload succeeds but
|
||||
the response never makes it back to the client, we want the client to
|
||||
know about the uploaded UUID so it can delete it later to prevent an
|
||||
orphan.
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||||
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||||
We maintain a list of UUIDs locally (not simply the last UUID) because
|
||||
multiple upload attempts could fail the same way as the previous
|
||||
paragraph describes and we have no way of knowing which (if any)
|
||||
actually succeeded. The safest approach is to assume every document
|
||||
produced managed to get uploaded some how.
|
||||
|
||||
We store the UUIDs on a file on disk and not anywhere else because we
|
||||
want storage to be robust. We originally stored UUIDs in preferences,
|
||||
which only flush to disk periodically. Writes to preferences were
|
||||
apparently getting lost. We switched to writing directly to files to
|
||||
eliminate this window.
|
||||
|
||||
Legal and Privacy Concerns
|
||||
==========================
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||||
|
||||
Because Firefox Health Report collects and submits data to remote
|
||||
servers and is an opt-out feature, there are legal and privacy
|
||||
concerns over what data may be collected and submitted. **Additions or
|
||||
changes to submitted data should be signed off by responsible
|
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parties.**
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@ -0,0 +1,18 @@
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=======================
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Firefox Services Module
|
||||
=======================
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||||
|
||||
The ``/services`` directory contains code for a variety of application
|
||||
features that communicate with external services - hence its name.
|
||||
|
||||
It was originally created to hold code for Firefox Sync. Later, it
|
||||
became the location for code written by the Mozilla Services Client team
|
||||
and thus includes Firefox Health Report. This team no longer exists, but
|
||||
the directory remains.
|
||||
|
||||
.. toctree::
|
||||
:maxdepth: 1
|
||||
|
||||
metrics
|
||||
healthreport
|
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datareporting
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|
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@ -0,0 +1,130 @@
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.. _services_metrics:
|
||||
|
||||
============================
|
||||
Metrics Collection Framework
|
||||
============================
|
||||
|
||||
The ``services/metrics`` directory contains a generic data metrics
|
||||
collecting and persisting framework for Gecko applications.
|
||||
|
||||
Overview
|
||||
========
|
||||
|
||||
The Metrics framework by itself doesn't do much: it simply provides a
|
||||
generic mechanism for collecting and persisting data. It is up to users
|
||||
of this framework to drive collection and do something with the obtained
|
||||
data. A consumer of this framework is :ref:`firefox_health_report`.
|
||||
|
||||
Relationship to Telemetry
|
||||
-------------------------
|
||||
|
||||
Telemetry provides similar features to code in this directory. The two
|
||||
may be unified in the future.
|
||||
|
||||
Usage
|
||||
=====
|
||||
|
||||
To use the code in this directory, import Metrics.jsm. e.g.
|
||||
|
||||
Components.utils.import("resource://gre/modules/Metrics.jsm");
|
||||
|
||||
This exports a *Metrics* object which holds references to the main JS
|
||||
types and functions provided by this feature. Read below for what those
|
||||
types are.
|
||||
|
||||
Metrics Types
|
||||
=============
|
||||
|
||||
``Metrics.jsm`` exports a number of types. They are documented in the
|
||||
sections below.
|
||||
|
||||
Metrics.Provider
|
||||
----------------
|
||||
|
||||
``Metrics.Provider`` is an entity that collects and manages data. Providers
|
||||
are typically domain-specific: if you need to collect a new type of data,
|
||||
you create a ``Metrics.Provider`` type that does this.
|
||||
|
||||
Metrics.Measurement
|
||||
-------------------
|
||||
|
||||
A ``Metrics.Measurement`` represents a collection of related pieces/fields
|
||||
of data.
|
||||
|
||||
All data recorded by the metrics framework is modeled as
|
||||
``Metrics.Measurement`` instances. Instances of ``Metrics.Measurement``
|
||||
are essentially data structure descriptors.
|
||||
|
||||
Each ``Metrics.Measurement`` consists of a name and version to identify
|
||||
itself (and its data) as well as a list of *fields* that this measurement
|
||||
holds. A *field* is effectively an entry in a data structure. It consists
|
||||
of a name and strongly enumerated type.
|
||||
|
||||
Metrics.Storage
|
||||
---------------
|
||||
|
||||
This entity is responsible for persisting collected data and state.
|
||||
|
||||
It currently uses SQLite to store data, but this detail is abstracted away
|
||||
in order to facilitate swapping of storage backends.
|
||||
|
||||
Metrics.ProviderManager
|
||||
-----------------------
|
||||
|
||||
High-level entity coordinating activity among several ``Metrics.Provider``
|
||||
instances.
|
||||
|
||||
Providers and Measurements
|
||||
==========================
|
||||
|
||||
The most important types in this framework are ``Metrics.Provider`` and
|
||||
``Metrics.Measurement``, henceforth known as ``Provider`` and
|
||||
``Measurement``, respectively. As you will see, these two types go
|
||||
hand in hand.
|
||||
|
||||
A ``Provider`` is an entity that *provides* data about a specific subsystem
|
||||
or feature. They do this by recording data to specific ``Measurement``
|
||||
types. Both ``Provider`` and ``Measurement`` are abstract base types.
|
||||
|
||||
A ``Measurement`` implementation defines a name and version. More
|
||||
importantly, it also defines its storage requirements and how
|
||||
previously-stored values are serialized.
|
||||
|
||||
Storage allocation is performed by communicating with the SQLite
|
||||
backend. There is a startup function that tells SQLite what fields the
|
||||
measurement is recording. The storage backend then registers these in
|
||||
the database. Internally, this is creating a new primary key for
|
||||
individual fields so later storage operations can directly reference
|
||||
these primary keys in order to retrieve data without having to perform
|
||||
complicated joins.
|
||||
|
||||
A ``Provider`` can be thought of as a collection of ``Measurement``
|
||||
implementations. e.g. an Addons provider may consist of a measurement
|
||||
for all *current* add-ons as well as a separate measurement for
|
||||
historical counts of add-ons. A provider's primary role is to take
|
||||
metrics data and write it to various measurements. This effectively
|
||||
persists the data to SQLite.
|
||||
|
||||
Data is emitted from providers in either a push or pull based mechanism.
|
||||
In push-based scenarios, the provider likely subscribes to external
|
||||
events (e.g. observer notifications). An event of interest can occur at
|
||||
any time. When it does, the provider immediately writes the event of
|
||||
interest to storage or buffers it for eventual writing. In pull-based
|
||||
scenarios, the provider is periodically queried and asked to populate
|
||||
data.
|
||||
|
||||
SQLite Storage
|
||||
==============
|
||||
|
||||
``Metrics.Storage`` provides an interface for persisting metrics data to a
|
||||
SQLite database.
|
||||
|
||||
The storage API organizes values by fields. A field is a named member of
|
||||
a ``Measurement`` that has specific type and retention characteristics.
|
||||
Some example field types include:
|
||||
|
||||
* Last text value
|
||||
* Last numeric value for a given day
|
||||
* Discrete text values for a given day
|
||||
|
||||
See ``storage.jsm`` for more.
|
||||
|
|
@ -1,63 +0,0 @@
|
|||
=====================
|
||||
Firefox Health Report
|
||||
=====================
|
||||
|
||||
This directory contains the implementation of the Firefox Health Report
|
||||
(FHR).
|
||||
|
||||
Firefox Health Report is a background service that collects application
|
||||
metrics and periodically submits them to a central server.
|
||||
|
||||
Implementation Notes
|
||||
====================
|
||||
|
||||
healthreporter.jsm contains the main interface for FHR, the
|
||||
*HealthReporter* type. An instance of this is created by the data
|
||||
reporting service. See /services/datareporting/.
|
||||
|
||||
providers.jsm contains numerous Metrics.Provider and Metrics.Measurement
|
||||
used for collecting application metrics. If you are looking for the FHR
|
||||
probes, this is where they are.
|
||||
|
||||
Preferences
|
||||
===========
|
||||
|
||||
Preferences controlling behavior of Firefox Health Report live in the
|
||||
*datareporting.healthreport.* branch.
|
||||
|
||||
Some important preferences are:
|
||||
|
||||
* **service.enabled** - Controls whether the entire health report
|
||||
service runs. The overall service performs data collection, storing, and
|
||||
submission. This is the primary kill switch for Firefox Health Report
|
||||
outside of the build system variable. i.e. if you are using an
|
||||
official Firefox build and wish to disable FHR, this is what you
|
||||
should change.
|
||||
|
||||
* **uploadEnabled** - Whether uploading of data is enabled. This
|
||||
is the preference the checkbox in the UI reflects. If this is
|
||||
disabled, FHR still collects data - it just doesn't upload it.
|
||||
|
||||
If the entire service is disabled, you lose data collection. This means that
|
||||
data analysis won't be available because there is no data to analyze!
|
||||
|
||||
Registering Providers
|
||||
=====================
|
||||
|
||||
Firefox Health Report providers are registered via the category manager.
|
||||
See HealthReportComponents.manifest for providers defined in this
|
||||
directory.
|
||||
|
||||
Essentially, the category manager receives the name of a JS type and the
|
||||
URI of a JSM to import that exports this symbol. At run-time, the
|
||||
providers registered in the category manager are instantiated. This
|
||||
allows for a loose coupling of providers which in turns makes managing
|
||||
the code behind the providers much simpler.
|
||||
|
||||
Other Notes
|
||||
===========
|
||||
|
||||
There are many legal and privacy concerns with this code, especially
|
||||
around the data that is submitted. Changes to submitted data should be
|
||||
signed off by responsible parties.
|
||||
|
||||
|
|
@ -1,109 +0,0 @@
|
|||
============================
|
||||
Metrics Collection Framework
|
||||
============================
|
||||
|
||||
This directory contains generic code for collecting and persisting
|
||||
metrics data for Gecko applications.
|
||||
|
||||
Overview
|
||||
========
|
||||
|
||||
Metrics by itself doesn't do much. It simply provides a framework for
|
||||
collecting data. It is up to users of this framework to hook up the
|
||||
individual components into a system that makes sense for their purposes.
|
||||
An example consumer of Metrics is Firefox Health Report (see
|
||||
/services/healthreport).
|
||||
|
||||
Relationship to Telemetry
|
||||
-------------------------
|
||||
|
||||
Telemetry provides similar features to code in this directory. The two
|
||||
may be unified in the future.
|
||||
|
||||
Type Overview
|
||||
=============
|
||||
|
||||
This directory defines a number of JavaScript *types*/*classes*:
|
||||
|
||||
Metrics.Provider
|
||||
An entity that collects and manages data. A provider is typically
|
||||
domain-specific. e.g. AddonsProvider, SearchesProvider.
|
||||
|
||||
Metrics.Measurement
|
||||
Represents a collection of related pieces/fields of data. Instances of
|
||||
these are essentially data structure descriptors.
|
||||
|
||||
Metrics.Storage
|
||||
Persistent SQLite-backed store for collected metrics data and state.
|
||||
|
||||
Metrics.ProviderManager
|
||||
High-level entity coordinating activity among several Metrics.Provider
|
||||
instances.
|
||||
|
||||
SQLite Storage
|
||||
==============
|
||||
|
||||
*Metrics.Storage* provides an interface for persisting metrics data to a
|
||||
SQLite database.
|
||||
|
||||
The storage API organizes values by fields. A field is a named member of
|
||||
a Measurement that has specific type and retention characteristics. Some
|
||||
example field types include:
|
||||
|
||||
* Last text value
|
||||
* Last numeric value for a given day
|
||||
* Discrete text values for a given day
|
||||
|
||||
See storage.jsm for more.
|
||||
|
||||
While SQLite is used under the hood, this implementation detail is
|
||||
hidden from the consumer.
|
||||
|
||||
Providers and Measurements
|
||||
==========================
|
||||
|
||||
The most important types in this framework are *Metrics.Provider* and
|
||||
*Metrics.Measurement*, henceforth known as *Provider* and *Measurement*,
|
||||
respectively. As you will see, these two types go hand in hand.
|
||||
|
||||
A Provider is an entity that *provides* data about a specific subsystem
|
||||
or feature. They do this by recording data to specific Measurement
|
||||
types. Both Provider and Measurement are abstract base types.
|
||||
|
||||
A Measurement implementation defines a name and version. More
|
||||
importantly, it also defines its storage requirements and how
|
||||
previously-stored values are serialized.
|
||||
|
||||
Storage allocation is performed by communicating with the SQLite
|
||||
backend. There is a startup function that tells SQLite what fields the
|
||||
measurement is recording. The storage backend then registers these in
|
||||
the database. Internally, this is creating a new primary key for
|
||||
individual fields so later storage operations can directly reference
|
||||
these primary keys in order to retrieve data without having to perform
|
||||
complicated joins.
|
||||
|
||||
A Provider can be thought of as a collection of Measurement
|
||||
implementations. e.g. an Addons provider may consist of a measurement
|
||||
for all *current* add-ons as well as a separate measurement for
|
||||
historical counts of add-ons. A provider's primary role is to take
|
||||
metrics data and write it to various measurements. This effectively
|
||||
persists the data to SQLite.
|
||||
|
||||
Data is emitted from providers in either a push or pull based mechanism.
|
||||
In push-based scenarios, the provider likely subscribes to external
|
||||
events (e.g. observer notifications). An event of interest can occur at
|
||||
any time. When it does, the provider immediately writes the event of
|
||||
interest to storage or buffers it for eventual writing. In pull-based
|
||||
scenarios, the provider is periodically queried and asked to populate
|
||||
data.
|
||||
|
||||
Usage
|
||||
=====
|
||||
|
||||
To use the code in this directory, import Metrics.jsm. e.g.
|
||||
|
||||
Components.utils.import("resource://gre/modules/Metrics.jsm");
|
||||
|
||||
This exports a *Metrics* object which holds references to the main JS
|
||||
types and functions provided by this feature.
|
||||
|
||||
|
|
@ -24,3 +24,5 @@ if CONFIG['MOZ_SERVICES_METRICS']:
|
|||
|
||||
if CONFIG['MOZ_SERVICES_SYNC']:
|
||||
PARALLEL_DIRS += ['sync']
|
||||
|
||||
SPHINX_TREES['services'] = 'docs'
|
||||
|
|
|
|||
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