Notes from watching other people's websites

What breaks in production on sites you did not build, why a status code rarely tells you, and what to do once you know. Written from a fleet we watch ourselves.

A full disk arrives as a 500, or as a login that fails
A full disk arrives as a 500, or as a login that fails
14/09/2026 · Laurent
HTTP status codes
Read more >
Cloudflare 522 means the packets went nowhere
Cloudflare 522 means the packets went nowhere
10/09/2026 · Laurent
HTTP status codes
Read more >
The only outage that arrives with a publication date
The only outage that arrives with a publication date
07/09/2026 · Laurent
TLS and certificates
Read more >
Alert fatigue is measured in minutes, not in annoyance
Alert fatigue is measured in minutes, not in annoyance
03/09/2026 · Laurent
Monitoring practice
Read more >
PHP under cron is not the PHP your site runs on
PHP under cron is not the PHP your site runs on
31/08/2026 · Laurent
Scheduled tasks
Read more >
Every hour, and the traffic jam at minute zero
Every hour, and the traffic jam at minute zero
27/08/2026 · Laurent
Scheduled tasks
Read more >
An A record points at an address you do not own
An A record points at an address you do not own
24/08/2026 · Laurent
DNS
Read more >
What a cron job is, when you have just inherited one
What a cron job is, when you have just inherited one
20/08/2026 · Laurent
Scheduled tasks
Read more >
Decoding a certificate somebody emailed you
Decoding a certificate somebody emailed you
17/08/2026 · Laurent
TLS and certificates
Read more >
301 vs 302: the choice is cheap, the chain is what costs you
301 vs 302: the choice is cheap, the chain is what costs you
13/08/2026 · Laurent
HTTP status codes
Read more >
Every five minutes, and the run that never finished
Every five minutes, and the run that never finished
10/08/2026 · Laurent
Scheduled tasks
Read more >
Cron on Linux: where the job lives, where output goes
Cron on Linux: where the job lives, where output goes
06/08/2026 · Laurent
Scheduled tasks
Read more >
dig: NOERROR with an empty answer is not an error
dig: NOERROR with an empty answer is not an error
03/08/2026 · Laurent
DNS
Read more >
Clients read one number in your white label report
Clients read one number in your white label report
30/07/2026 · Laurent
Agency operations
Read more >
99.9% uptime is eight hours and forty-five minutes a year
99.9% uptime is eight hours and forty-five minutes a year
30/07/2026 · Laurent
Monitoring practice
Read more >
Pinging a website tests something else entirely
Pinging a website tests something else entirely
30/07/2026 · Laurent
Monitoring practice
Read more >
Cron calculators, and the question they cannot answer
Cron calculators, and the question they cannot answer
30/07/2026 · Laurent
Scheduled tasks
Read more >
That cron expression was written for another cron
That cron expression was written for another cron
30/07/2026 · Laurent
Scheduled tasks
Read more >
Cron syntax: everything after the fifth field
Cron syntax: everything after the fifth field
30/07/2026 · Laurent
Scheduled tasks
Read more >
The six X.509 fields that decide whether TLS works
The six X.509 fields that decide whether TLS works
30/07/2026 · Laurent
TLS and certificates
Read more >
The certificate field browsers read, and CN is not it
The certificate field browsers read, and CN is not it
30/07/2026 · Laurent
TLS and certificates
Read more >
Self-signed certificates: three cases where they are right
Self-signed certificates: three cases where they are right
30/07/2026 · Laurent
TLS and certificates
Read more >
Your sitemap has one field Google reads, and lying loses it
Your sitemap has one field Google reads, and lying loses it
30/07/2026 · Laurent
Indexing and crawling
Read more >
Down for everyone, or just for you? A sixty-second answer
Down for everyone, or just for you? A sixty-second answer
30/07/2026 · Laurent
Monitoring practice
Read more >
Website status: seven layers, and free checkers read four
Website status: seven layers, and free checkers read four
30/07/2026 · Laurent
Monitoring practice
Read more >
A WordPress maintenance plan is insurance sold as chores
A WordPress maintenance plan is insurance sold as chores
30/07/2026 · Laurent
WordPress in production
Read more >
Traceroute: the middle hops lie and the last one does not
Traceroute: the middle hops lie and the last one does not
30/07/2026 · Laurent
DNS
Read more >
A CNAME takes over the whole name, which is why mail breaks
A CNAME takes over the whole name, which is why mail breaks
30/07/2026 · Laurent
DNS
Read more >
nslookup: five invocations, and three ways it misleads you
nslookup: five invocations, and three ways it misleads you
30/07/2026 · Laurent
DNS
Read more >
MX records: the site is up and the mail is gone
MX records: the site is up and the mail is gone
30/07/2026 · Laurent
DNS
Read more >
SSL handshake failed: the step it died on names the cause
SSL handshake failed: the step it died on names the cause
30/07/2026 · Laurent
TLS and certificates
Read more >

Cookies here just count visits, with Google Analytics, and only if you say yes. What we store