Databay field notes
Proxy guides, experiments & operator notes
Engineering guides and first-party measurements for people operating proxy-backed data systems.
- 01Guides20
- 02Tutorials13
- 03Comparisons5
- 04Research5
Newest update Aug 09, 2026 · methodology-open research
All articles
43 entries
ERR_NAME_NOT_RESOLVED: What It Means and How to Fix It
ERR_NAME_NOT_RESOLVED means DNS returned no address, so your browser never connected. Two commands that localize it, then the fixes that...
12 min readRead
ERR_TOO_MANY_REDIRECTS: How to Break a Redirect Loop
The browser gave up on a redirect loop. Fix it as a visitor in two minutes, see the loop with curl, and repair the server rules causing it.
10 min readRead
ERR_TUNNEL_CONNECTION_FAILED: Causes and How to Fix It
ERR_TUNNEL_CONNECTION_FAILED means a proxy would not open the CONNECT tunnel HTTPS needs. What a tunnel is, and fixes ranked by the real...
12 min readRead
Error 1015: You Are Being Rate Limited (How to Fix It)
Error 1015 is Cloudflare enforcing a site's rate limit at the edge. Why you tripped it, how long it lasts, and fixes for visitors and...
10 min readRead
Error 1020 Access Denied: Causes and How to Fix It
Error 1020 means a site's own firewall rule refused your request at the edge. Why you matched it, and the one thing that actually...
12 min readRead
Error 522: Connection Timed Out and Whose Fault It Is
Error 522 means a CDN edge could not get a usable connection to the site's origin. Why it is almost never the visitor's fault, and the...
12 min readRead
What Is Msftconnecttest.com and Why Does It Redirect?
Msftconnecttest.com is how Windows checks for internet access. Why it is not malware, why the redirect tab opens, and the fixes that work.
12 min readRead
What Is Doubleclick.net? Google's Ad and Tracking Domain
Doubleclick.net is Google's ad serving and measurement domain. Why it loads on sites you visit, whether it is malware, and what limiting...
12 min readRead
What Is Gstatic.com? Google's Static Content Domain
Gstatic.com is Google's cookieless domain for static files like fonts and scripts. What it does, why devices ping it, and what breaks if...
10 min readRead
Proxy Ports Explained: Why the Number Is Convention
A proxy port number is a convention, not a promise. Learn what 8080, 3128, and 1080 mean and how to tell a wrong-port error from a...
7 min readRead
What Are Backconnect Proxies? One Gateway, Many Exits
A backconnect proxy is one gateway address in front of a rotating pool of exits. See the architecture demonstrated on a local gateway.
8 min readRead
What Is a Web Proxy? How URL-Based Browsing Works
A web proxy is a website that fetches pages for you and rewrites every link. See exactly what it changes, what breaks, and what its...
11 min readRead
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