net/network_error_logging/README.md - cobalt - Git at Google

 # Network Error Logging (NEL)

 Network Error Logging (NEL) provides out-of-band reporting of network errors
 via the Reporting API (see `//net/reporting`). Site operators can specify a
 NEL policy that defines the Reporting endpoint(s) on which they wish to receive
 reports about client-side errors encountered while connecting to the site. The
 draft spec can be found [here](https://w3c.github.io/network-error-logging/).

 This directory contains the core implementation of NEL.

 ## Implementation overview

 Most of the action takes place in
 [`NetworkErrorLoggingService`](https://source.chromium.org/chromium/chromium/src/+/main:net/network_error_logging/network_error_logging_service.h;l=42;drc=a9e9d6cbb3e5920f9207118cf9501ff0745bb536),
 which handles receiving/processing `NEL:` response headers and
 generating/queueing reports about network requests. The
 `NetworkErrorLoggingService` is owned by the `URLRequestContext`.

 Information about network requests comes directly from
 [`HttpNetworkTransaction`](https://source.chromium.org/chromium/chromium/src/+/main:net/http/http_network_transaction.cc;l=1364;drc=a9e9d6cbb3e5920f9207118cf9501ff0745bb536),
 which informs `NetworkErrorLoggingService` of the details of the request such
 as the remote IP address and outcome (a `net::Error` code).

 The `NetworkErrorLoggingService` finds a NEL policy applicable to the request
 (previously set by a `NEL` header), and if one exists, potentially queues a
 NEL report to be uploaded out-of-band to the policy's specified Reporting
 endpoint via the
 [`ReportingService`](https://source.chromium.org/chromium/chromium/src/+/main:net/reporting/reporting_service.h;l=56;drc=c3305c04ac6800d488bfc8b2f3249fd13186984a).

 Received NEL policies are persisted to disk by a `PersistentNelStore`, whose
 main implementation is the
 [`SqlitePersistentReportingAndNelStore`](https://source.chromium.org/chromium/chromium/src/+/main:net/extras/sqlite/sqlite_persistent_reporting_and_nel_store.h;l=30;drc=456596a0b27623349d38e49d0e9812b24d47d5d8).
	# Network Error Logging (NEL)

	Network Error Logging (NEL) provides out-of-band reporting of network errors
	via the Reporting API (see `//net/reporting`). Site operators can specify a
	NEL policy that defines the Reporting endpoint(s) on which they wish to receive
	reports about client-side errors encountered while connecting to the site. The
	draft spec can be found [here](https://w3c.github.io/network-error-logging/).

	This directory contains the core implementation of NEL.

	## Implementation overview

	Most of the action takes place in
	[`NetworkErrorLoggingService`](https://source.chromium.org/chromium/chromium/src/+/main:net/network_error_logging/network_error_logging_service.h;l=42;drc=a9e9d6cbb3e5920f9207118cf9501ff0745bb536),
	which handles receiving/processing `NEL:` response headers and
	generating/queueing reports about network requests. The
	`NetworkErrorLoggingService` is owned by the `URLRequestContext`.

	Information about network requests comes directly from
	[`HttpNetworkTransaction`](https://source.chromium.org/chromium/chromium/src/+/main:net/http/http_network_transaction.cc;l=1364;drc=a9e9d6cbb3e5920f9207118cf9501ff0745bb536),
	which informs `NetworkErrorLoggingService` of the details of the request such
	as the remote IP address and outcome (a `net::Error` code).

	The `NetworkErrorLoggingService` finds a NEL policy applicable to the request
	(previously set by a `NEL` header), and if one exists, potentially queues a
	NEL report to be uploaded out-of-band to the policy's specified Reporting
	endpoint via the
	[`ReportingService`](https://source.chromium.org/chromium/chromium/src/+/main:net/reporting/reporting_service.h;l=56;drc=c3305c04ac6800d488bfc8b2f3249fd13186984a).

	Received NEL policies are persisted to disk by a `PersistentNelStore`, whose
	main implementation is the
	[`SqlitePersistentReportingAndNelStore`](https://source.chromium.org/chromium/chromium/src/+/main:net/extras/sqlite/sqlite_persistent_reporting_and_nel_store.h;l=30;drc=456596a0b27623349d38e49d0e9812b24d47d5d8).