Telemetry: Record a Page Set

Telemetry: Record a Page Set

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How do I record a Page Set?

Run record_wpr

To record a Page Set use the record_wpr script.  Your command will look something like this:

$ tools/perf/record_wpr --browser=(release|system) page_set

For example, to record the top_25.json file:

$ tools/perf/record_wpr --browser=system tools/perf/page_sets/top_25.json

To record only some pages in the Page Set, use --page-filter, for example this command will just record the wikipedia page:

$ tools/perf/record_wpr --browser=system --page-filter=wikipedia tools/perf/page_sets/top_25.json

record_wpr generates a .wpr file, which is the recorded data, a corresponding .wpr.sha1 file, and a .json metadata file. The path to the metadata file must be specified in the .json page set before it can be recorded. For example top_25.json has the following entry:
"archive_data_file": "data/top_25.json",

Upload the data to Cloud Storage

We avoid checking in the .wpr file, to avoid bloating everyone's Chromium checkouts. Instead, we upload them to Cloud Storage and download them as needed.

To do this, check in only the .sha1 and .json files. When you do git cl upload, a PRESUBMIT script will upload the .wpr file to Google Storage.

Why do we record page sets?

We record page sets so we can run benchmarks stably over the same web content. By recording live sites, we can control variables such as the website itself changing or network conditions.

What is Web Page Replay

Web Page Replay is a service that allows us to capture and store HTTP requests and responses.