Tag
hashing
- Jul 21, 2026 Counting Distinct Elements with HyperLogLog Registers How a fixed array of small registers estimates cardinality to within about one percent, why the estimator uses a harmonic mean, and how register-wise maximum makes sketches mergeable. algorithms
- May 29, 2026 Content-Addressed Build Cache Keys: What Must Go Into the Hash A cache hit is only sound if the key covers every input that can change the output. The compiler binary, its flags, the header contents, and the transitive environment all belong in it; the clock and the path usually do not. compilers
- Apr 26, 2026 Content-Addressed Provenance Graphs for Derived Outputs Recording each step as a node keyed by the hash of its inputs, code, parameters, and environment, so that any output can be traced back to the exact bytes and commands that produced it. scientific computing
- Jan 18, 2026 Link Aggregation and the Hash That Chooses a Member How LACP bundles links, why the distributor hashes rather than round-robins, and the ordering guarantee that constrains every possible choice. networking
- Aug 25, 2025 How a Bloom Filter Trades Bits for a False-Positive Rate The bit-array layout behind Bloom filters, the derivation of the false-positive probability, and how the bits-per-key budget fixes the achievable error. data structures
- Jul 24, 2025 Merkle Trees, Range Digests, and Finding Divergence Without Reading Everything How a tree of hashes narrows a comparison between two replicas to the differing leaves, what it costs to maintain under writes, and why the leaves must align. filesystems
- Jul 18, 2025 Link Aggregation Member Selection and the Mismatches That Stall It How frames are hashed onto bundle members, why a single flow cannot exceed one link, and which LACP negotiation failures leave a bundle passing some traffic. networking
- Dec 27, 2024 UDP Source Port Entropy and Underlay ECMP Why a tunnel collapses many flows onto one underlay path, how deriving the outer source port from an inner-header hash restores path diversity, and when the hash runs out of entropy. networking
- Oct 13, 2024 Disk Image Integrity and Chain of Custody Mechanics What a hash establishes about a disk image, why acquisition order determines what the image can prove, and how write blockers and hashing after the fact differ in evidentiary value. security
- Oct 1, 2024 Git's Object Model: Content-Addressed Blobs, Trees, and Commits How Git frames and hashes objects, why a rename leaves no trace in storage, and what the four object types cost when content changes. developer tools
- Jul 10, 2023 Count-Min Sketch: Why the Minimum of Overestimates Is the Estimate The counter grid, the derivation of width e over epsilon and depth ln of one over delta, and why conservative update shrinks error without changing the guarantee. algorithms
- Mar 28, 2023 Polynomial Rolling Hashes and the Rabin-Karp Trade How a rolling hash compares substrings in constant time, why collision probability depends on the modulus, and which arithmetic choices fail under adversarial input. algorithms