This page describes Service Extensions logs for Media CDN plugins and how you can view and correlate the information in log messages.
Log messages
Service Extensions supports generating log messages during the execution of your plugin. Recording logs is disabled by default. To record logs for a plugin, enable it while creating the plugin or updating it.
Plugin log records are annotated with the following contextual information:
- Standard log annotations, such as timestamp and log level.
- The identity of the plugin that generated the message.
- The plugin callback in which the log message was generated.
- A
requestIdtrace identifier that helps determine the request log that a log message is associated with.
Logs that are pertinent to Service Extensions are of one of the following categories:
Plugin log messages generated by a logging call, such as
info!(...)for Rust orLOG_INFOfor C++. Service Extensions exports these log messages to Cloud Logging. You can view these messages under thenetworkactions.googleapis.comservice.Media CDN log messages for HTTP requests to
EdgeCacheServiceresources with an associated Wasm action. These are regular Media CDN log entries that are viewable under theedgecache.googleapis.comservice.
View log messages
Logs can be viewed by building queries in the Logs Explorer.
You can view plugin logs in the following formats:
As standalone Service Extensions logs.
In this view, each plugin log message is recorded in its own log record and isn't automatically associated with request log information.
These log messages are in the
networkactions.googleapis.com/wasm_plugin_activitylog with the resource typenetworkactions.googleapis.com/WasmPluginVersion.The system might also add informational log messages to this log. For example, if there's a plugin failure when a plugin invocation exceeds CPU or memory limits, a message of
ERRORseverity is logged. Such messages can also be seen in Error Reporting.Correlated with the corresponding Media CDN request logs.
While viewing request logs, when you expand a request log entry, the plugin logs related to the request appear nested under the request log. This view helps you understand plugin logs in the context of their associated request.
For more information, see View correlated log entries in the Logs Explorer.
Log samples
Consider a sample Service Extensions log entry. The value of
message is passed to the plugin's LOG_INFO call. The severity value
depends on the log level used in the plugin log call. In the labels section,
the value of networkactions.googleapis.com/operation is
HTTP_REQUEST_HEADER, which indicates that the logged operation is the
on_http_request_headers plugin callback.
{
"insertId": "65224aac-0000-24bd-a0e1-582429bd544c@a1",
"jsonPayload": {
"@type": "type.googleapis.com/google.cloud.networkactions.logging.v1.WasmPluginLogEntry",
"metroIataCode": "ber",
"proxyRegionCode": "DE",
"message": "[add_header_plugin.cc:26]::onRequestHeaders() AddHeaderStreamContext::onRequestHeaders called",
"requestId": "effc0311-6716-431b-9e2a-7586835fdff1"
},
"resource": {
"type": "networkactions.googleapis.com/WasmPluginVersion",
"labels": {
"plugin_version": "prod-1",
"resource_container": "projects/123456789",
"location": "global",
"plugin_name": "add-headers-plugin-prod-resource"
}
},
"timestamp": "2023-05-10T03:05:43.317015458Z",
"severity": "INFO",
"labels": {
"networkactions.googleapis.com/operation": "HTTP_REQUEST_HEADERS"
},
"logName": "projects/123456789/logs/networkactions.googleapis.com%2Fwasm_plugin_activity",
"trace": "projects/123456789/traces/effc0311-6716-431b-9e2a-7586835fdff1",
"receiveTimestamp": "2023-05-10T03:05:44.207265284Z"
}
The related Media CDN log entry appears as follows. The
requestId and trace values in both log messages are the same.
{
"insertId": "6c95cc54-0000-26ba-ba73-f403043c328c@a1",
"jsonPayload": {
"cacheMode": "USE_ORIGIN_HEADERS",
"@type": "type.googleapis.com/google.cloud.edgecache.v1.EdgeCacheLogEntry",
"wasmAction": "add-headers-action-prod-resource",
"cacheKeyFingerprint": "f04d02bb12f2e79e",
"proxyStatus": "Google-Edge-Cache",
"clientCity": "Erlangen",
"clientAsn": "8881",
"origin": "example-origin",
"cacheId": "ber",
"tlsVersion": "NONE",
"latency": "0.002840304s",
"originIp": "142.250.145.128",
"requestId": "effc0311-6716-431b-9e2a-7586835fdff1",
"clientRegionCode": "DE",
"originalRequestId": "7656c418-df7c-4ae5-9db5-4f247ec5a82c",
"httpTtfb": "0.002814903s",
"metroIataCode": "BER",
"proxyRegionCode": "DE",
"cacheStatus": "hit"
},
"httpRequest": {
"requestMethod": "GET",
"requestUrl": "https://example.com/image.jpg",
"requestSize": "1631",
"status": "200",
"responseSize": "402907",
"userAgent": "Wtrace",
"remoteIp": "2001:1438:1:19::5",
"protocol": "HTTP/1.1"
},
"resource": {
"type": "edgecache.googleapis.com/EdgeCacheRouteRule",
"labels": {
"location": "global",
"route_destination": "projects/123456789/locations/global/edgeCacheOrigins/example-origin",
"matched_path": "/turing/",
"route_type": "ORIGIN",
"path_matcher_name": "routes",
"resource_container": "projects/123456789",
"service_name": "example-service"
}
},
"timestamp": "2023-05-10T03:05:43.321347304Z",
"logName": "projects/bdn-prober/logs/edgecache.googleapis.com%2Fedge_cache_request",
"trace": "projects/1069774196212/traces/effc0311-6716-431b-9e2a-7586835fdff1",
"receiveTimestamp": "2023-05-10T03:05:49.919781008Z"
}
Limitations
Plugins are limited to logging up to 16 KiB of payload data per client HTTP request. This amount is divided across multiple logging calls that are associated with a given HTTP request. The limit applies only to log message text, not to additional metadata added to the log record by Service Extensions.
For example, if an on_http_request_headers callback makes two logging calls
with 4 KiB messages each, and then an on_http_response_headers callback
attempts to make three logging calls with 4 KiB messages each for the same
HTTP request, the third logging message is dropped. A log message is added
to record the number of plugin-generated log messages that were dropped.