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View, search, and filter your site's web request logs with Cloud Logging

You can link your Firebase project to Cloud Logging to view, search, and filter your web request logs for each of your Hosting sites. These logs are from the CDN that's automatically provided by Firebase, so every request to your site and the associated request data are logged.

Here are some things you do with Cloud Logging logs. Visit each section of this page to learn details.

  • Better understand your site — Learn from where and when you have visits to your site, your site's response statuses, the latency of end user requests, and more.

  • Filter your logs with queries — Leverage automatically collected data to filter and plot data associated with each request or your site.

  • Use logs-based metrics — Create Cloud Monitoring charts and alerting policies from predefined system metrics or user-defined metrics.

  • Export logs to other Google Cloud tools — Use logs data in other tools (like BigQuery and Data Studio) for more powerful analysis and correlation.

If you have multiple Hosting sites in your project, you can select which of your Hosting sites will export logs. You can then filter and view your logs data by Hosting site and even by domain. By selecting specific Hosting sites to export logs, you can also control the amount of data processed for your project.

  1. Click Link in the Cloud Logging integration card in the Firebase console.

    To link or unlink Cloud Logging, you need the permissions bundled into any of the following roles: project Owner or Editor or Firebase Develop Admin.

  2. Follow the on-screen instructions to select which of your Hosting sites should export logs to Cloud Logging.

    If you already have one or more active Hosting sites, the linking workflow displays an estimated data usage level for logs from each of your Hosting sites. This value is estimated from the past 30 days.

After linking to Cloud Logging, logs for any new requests to your Hosting sites will usually show up within 30 minutes of the request being made.

You can also unlink Firebase Hosting from Cloud Logging, which stops exports of web request logs to Cloud Logging.

Monitor your data usage for logs

After linking to Cloud Logging, you can view the data usage level for logs from your Hosting sites:

Better understand your site

The Logs Viewer interface in the Google Cloud console offers tools to view your specific logs and data using queries and built-in filters and data panels. Learn more about filtering your logs with queries in the next section below.

  • Where is your site's traffic coming from at a granular level?
    You can view information about each request, including source IP, referer, city, and status.

  • When are users visiting your site?
    You can use the Histogram panel to see the distribution by specific time ranges. This can give you insight into the normal peaks and dips of your app's usage, as well as reveal any unexpected spikes in traffic.

  • What's the status distribution for end-user requests?
    You can view the status for each request and even diagnose requests that receive errors. You can filter your logs by Critical, Error or Warning.

  • How long does your site take to respond to a request?
    You can view your site's latency for each request using the latency value captured in each log.

  • Is your site taking advantage of content caching?
    Each log contains a cacheHit field to tell you if your site's resource was served quickly from Hosting's CDN cache, or if it had to make the full trip to the Hosting backend. This can help you improve your website's performance by making the most of Firebase's global CDN. For example, you can use the data to fine-tune the caching habits of your static assets and dynamic content.

  • What is the distribution of traffic to your various domains?
    If you have multiple domains or Hosting sites, you can filter your logs by domain or by site. This allows you to see how your traffic is distributed. When you filter by domain, you can track which domain is visited most frequently.

Filter your logs with queries

To learn about how to filter your logs with queries, visit Sample queries using Logs Viewer and Building log queries. The table below describes the fields available for those queries.

For Hosting, here are some initial filters for a query:

  • Resource (resource.type) — firebase_domain (Firebase Hosting Site Domain)
  • Log name (logName) — webrequests (Firebase Hosting)

Each log entry has a predefined structure and queryable fields (see LogEntry). For Hosting, some fields are standard to an HTTP request, but there are other field values which come from the processing that Hosting runs on each request.

Field Description
Firebase Hosting stores the following fields in the httpRequest object of the log entry.
These fields are defined in the HTTP specification.
cacheHit Whether or not the Hosting CDN had the resource of the response in cache
latency The request duration, in seconds with s postfix (for example, 1.256s)
protocol The protocol used for the request (for example, HTTP/1.1, HTTP/2, websocket)
referer The address of the previous web page from which a link to the currently requested page was followed (if present)
remoteIp The originating client IP for the request
requestMethod The request method (GET, POST, PUT, etc.)
requestSize The size of the request in bytes
requestUrl The full URL of the request (for example,
https://foo.web.app/bar or https://custom.domain.com?query=param)
responseSize The HTTP response size in bytes
serverIp not populated
status The HTTP response status (for example, 200 or 404)
userAgent The user-Agent header of the request
Firebase Hosting stores additional fields in the jsonPayload object of the log entry.
acceptEncoding (from the HTTP request) Which content encoding, usually a compression algorithm, the client supports (for example, gzip or compress)
billable Whether or not your project was billed for the request
customDomain Whether or not the request was made against a custom domain
hostname The hostname that the request was made against
remoteIpCountry The originating country of the request
remoteIpCity The originating city of the request

Use logs-based metrics

You can view and build logs-based metrics, then use these metrics in Cloud Monitoring to create charts and alerting policies.

  • Leverage predefined system metrics that are automatically recorded, such as the number of logging events that occurred within a specific time period.

  • Create user-defined metrics for your project. You can count the number of log entries that match a given query or keep track of particular values with the matching log entries. You can filter using regular expressions.

  • Use Cloud Monitoring to record the number of log entries containing particular messages or extract latency information reported in log entries. You can then use these metrics in charts and alerting policies.

Firebase Hosting also generates the following Hosting-specific logging metrics. These metrics are not specific to a log entry but rather to the specific Hosting site as a whole.

  • log_bytes: Total bytes of data usage for each site

  • response_count: Total count of responses written for the site

    This metric includes the field of HTTP status, so you can plot HTTP responses by status (as an example).

Export logs to other Google Cloud tools

You can also export your site's logs to other Google Cloud tools, like Cloud Monitoring or BigQuery, for example:

  • Using Cloud Monitoring, you can create log-based metrics that you can use in charts and alerting policies.

  • Using BigQuery, you can do any of the following:

    • Use Data Studio to generate dashboards of your Hosting data.
    • Run queries to get more insight into your requests (average response size, cache hits vs misses, etc.).
    • Learn which URLs your users actually request.
    • Combine your Hosting data with other Firebase data that you exported to BigQuery and query it in new ways.