Pipelining lets a client send several Redis commands without waiting for each reply before sending the next. It reduces request-response waiting and can amortize socket I/O overhead. Redis still executes the commands and produces their replies; batching is neither a promise of parallel execution nor a transaction boundary. ...
HTTP/2 removes HTTP response-order constraints by multiplexing streams, but those streams still share a TCP connection and its failure modes. One useful boundary is cancellation: terminating a request need not destroy its sibling requests or the reusable connection. That is a scoped capability, not a guarantee that streams never affect each other. ...
A CDN can shorten the path between a reader and a reusable response, while reducing requests to the origin. Those benefits depend on routing, cache contents, and policy. A domain pointing at a CDN does not prove that an object is cached, that the geographically nearest machine serves it, or that every request avoids the origin. ...
Unix domain sockets provide local interprocess communication without IP addresses, TCP ports, or an external network route. They still use kernel socket facilities, buffers, scheduling, and an application protocol. A pathname socket exposes a filesystem name, but Unix sockets can also be unnamed, and Linux supports abstract names. These naming forms have different access rules, so “a Unix socket is just a protected file” is incomplete. ...
Buffered file I/O can pass through a language buffer, the kernel page cache, and the storage stack at different times. Modified cache pages need writeback so their data reaches the backing filesystem and device. This separation can combine work and improve throughput, but it means that another reader seeing new bytes is not, by itself, evidence that a crash-safe storage boundary has completed. ...
A fingerprinted asset puts a digest of its bytes into its URL. Changing a stylesheet produces a different address, so a page can request the new representation without depending on every existing cache expiring simultaneously. The useful guarantee comes from the publishing process: once an address is released, its contents must remain consistent with that digest. ...
The Server-Timing response header lets a server attach named measurements to a response. Browser developer tools and performance APIs can then associate those measurements with the resource request. It is useful when the network waterfall shows a long wait but cannot explain whether backend work involved a database call, rendering, or another measured operation. The header supplies server-selected observations, not an independent browser measurement of those operations. ...
A queue with a hundred ready jobs and thousands of completed jobs can benefit from an index containing only ready work. PostgreSQL calls this a partial index: its predicate determines which table rows have entries. The benefit depends on the actual query population and write pattern, not simply on making every index smaller. ...