Internet Protocols · Cluster
HTTP
Messages, caching, and connection management.
- 01 HTTP Message Framing: Start Lines, Field Lines, and CRLF How an HTTP/1.1 message is divided into a start line, a field section, and a body, and which parts of that grammar still decide whether a parser succeeds.
- 02 Method Semantics: Safe, Idempotent, and Cacheable Requests What the three method properties actually license a client, cache, or proxy to do, and where the definitions stop matching what real methods do.
- 03 Status Codes, Interim Responses, and When a Response Has No Body How the three-digit status code steers client behaviour, why 1xx responses break naive parsers, and which statuses forbid or require a body.
- 04 Proactive Content Negotiation and the Quality Value Grammar How Accept, Accept-Language, and Accept-Encoding rank representations, what q-values order, and why Vary makes negotiation cacheable.
- 05 Conditional Requests: Entity Tags, Dates, and Preconditions How If-None-Match and If-Modified-Since turn a full response into 304, how strong and weak validators differ, and why the precondition order is fixed.
- 06 Cache Freshness, Age, and the Directive Precedence Rules How a cache computes whether a stored response is fresh, how Age accumulates across hops, and which directive wins when several apply.
- 07 Persistent Connections, Pipelining, and Connection Reuse Why HTTP/1.1 keeps the connection open, what pipelining actually requires of a server, and how idle timeouts and half-closed sockets break reuse.
- 08 Intermediaries, Hop-by-Hop Fields, and the Via Chain How proxies, gateways, and tunnels differ, which fields an intermediary must consume rather than forward, and what forwarding does to message semantics.
- 09 Byte Ranges, Partial Responses, and Range Request Cost How Range and Content-Range select a byte window, when a server must answer 206 rather than 200, and why many small ranges are a denial-of-service shape.
- 10 Message Delimitation and the Mechanics of Request Smuggling How Content-Length, Transfer-Encoding, and connection close define where a message ends, and how disagreements between parsers turn that boundary into an attack.