Read a failure one layer at a time
A connection can fail before a name is resolved, during a secure handshake or after a request arrives. Naming the layer narrows the next check.
The complete index
Notes
A notebook for following a request through names, connections and responses.
Begin with any of these seven notes. The section list and neighbouring readings offer a route back when a question changes.
Keep a useful observation
A useful observation begins with a small question. Decide which result would help answer it before choosing what to collect.
Keep names and addresses separate
A name is a durable label. An address is one answer about where to try a connection. Treating them as separate observations makes a problem easier to describe.
Leave a connection check easy to repeat
A short record of the question, conditions and result is usually more reusable than a large collection of unexplained output.
Compare two attempts fairly
Two numbers become a useful comparison only when their conditions are known. The differences around the numbers can matter more than their size.
Delay and throughput answer different questions
A quick first reply and a fast transfer describe different parts of an experience. A single number cannot stand in for both.
Finish a small piece of work
An action finishing is useful evidence. The result that another person will use deserves its own check and a short route back.