Field Notes / Systems & Networks

Keep systems simple.
Make the details count.

Practical notes about Linux administration, network measurements, and maintaining small services.

01 / Networking

Measure the path, not just the endpoint

Latency, throughput, and reliability describe different properties of a connection. Compare the same endpoints at different times, and record whether the route is direct or proxied.

Read the TCP throughput testing framework
02 / Operations

Backups are part of the change

Before updating a service, preserve its working configuration and write down the rollback procedure. Validate the new configuration before restarting, then check the actual running process.

03 / Security

Certificates need a lifecycle

Issuing a certificate is only the first step. Automated renewal, a tested reload hook, and an expiration check keep a small HTTPS service reliable.

Let's Encrypt documentation