This page is a spiritual successor to
gcping.com. That site pinged Cloud
Run in each region. Google is shutting it down and archiving
the GCPing repository. This page pings Cloud Storage in each Google Cloud region
instead.
The page sends 11 waves of probes. Each wave hits every region at
the same time. The first wave is discarded, because it includes the
TLS handshake and is a slow outlier. The table uses the median of
the other 10. Stop ends early. Restart discards one warmup wave,
then records one more, and keeps the samples you already have.
Requests go to a bucket that does not exist, at
storage.REGION.rep.googleapis.com. The global row uses
storage.googleapis.com. Each request returns 404. The
table shows the median time from request to response.
JavaScript can only report that end-to-end time here. The Resource
Timing API can split DNS, TCP, TLS, waiting, and download, but only
when the response includes a Timing-Allow-Origin
header. These Cloud Storage 404s do not send that header, and they
do not allow CORS, so the browser zeros the detailed timestamps.
The app still reads them and shows a note if a response includes
the breakdown.
Use the numbers to compare regions from where you are, not as a
lab RTT. Later probes often reuse the HTTP connection.