すべての記事
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Serving range requests for resumable downloads
A server that advertises Accept-Ranges: bytes, answers Range: bytes=start-end with 206 Partial Content and Content-Range, evaluates If-Range against a strong ETag, and returns 416 with Content-Range: bytes */length for unsatisfiable ranges lets clients resume interrupted downloads and read parts of large files. These steps cover the server side, the client side and the checks.
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Account lockout and password quality on Linux with pam_faillock and pwquality
pam_faillock locks an account after repeated failed logins and the faillock command inspects or clears that state; pam_pwquality enforces password-strength rules from pwquality.conf. Both are wired into PAM through authselect on RHEL-family systems and pam-auth-update on Debian/Ubuntu, not by hand-editing the PAM stack directly.
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Why NTP still runs inside virtual machines despite guest agents and paravirtual clocks
Virtual machines get time-related help from several layers — kvm-clock, guest agents, Hyper-V integration services — but none of them substitute for an NTP or chrony client running inside the guest. This article explains what each layer actually does and why time sync stays a guest-OS responsibility.
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Maintainer hand-over and bus factor: what a successor must be able to do on day one
A project survives its maintainer when a second person already holds every account and key, can perform a release from the written steps alone, and knows where decisions are recorded. PEP 541 shows what happens otherwise on PyPI: a project counts as abandoned only when the owner is unreachable, no release has appeared for twelve months and its home page shows no activity, and only then can it be handed to a new owner under the abandonment rule. GitHub's repository transfer moves issues, pull requests, stars and watchers with the code.
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ブランチごとのプレビュー環境：プルリクエストごとに1つデプロイし、マージ時に破棄する
各プルリクエストに専用URLで動くアプリケーションのコピーを用意します。コミットごとに1回だけビルドし、プルリクエスト番号で命名し、ローカルの初期データを投入し、外部サービスのサンドボックスへ接続します。URLをプルリクエストに投稿し、同時実行数を制限し、マージ、クローズ、非活動時にコピーとデータを削除します。
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A personal decision journal: writing the entry before the outcome is known
A proposed format for an individual's decision journal: one entry per non-trivial choice written before acting, with the options considered, the expected outcome, the confidence stated as a number and a review date; the later review compares expectation with outcome and separates decision quality from outcome luck.
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A personal knowledge base as plain-text folders: inbox, notes, sources, projects, archive
A folder layout for a personal knowledge base that a person or an agent can keep for years: five top-level folders with different lifetimes, one note per file with a stable identifier and a small header, an index file kept by hand, and an archive rule instead of deletion; the structure stays flat so that search and links do not depend on where a file sits.
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大規模リポジトリでのスパースチェックアウトと部分クローンの活用
スパースチェックアウトは作業ツリーに現れるディレクトリを制限し（cone モードではディレクトリを列挙する）、--filter=blob:none を使う部分クローンはファイル内容のダウンロードを必要になるまで遅らせ、シャロークローンは履歴を切り詰める。3つは異なる問題を解決し、併用できるが、部分クローンには promisor リモートへのオンライン接続が必要となる。
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State-changing GET endpoints are the main source of unintended actions triggered by automated clients
Hypothesis: in web applications that perform state changes on GET (action links in emails, page?do=delete, one-click approvals), most state changes with no matching user session are caused by automated clients such as link prefetchers, mail security scanners, crawlers and retrying HTTP libraries, which RFC 9110 explicitly expects to fetch safe-method URIs freely and to repeat idempotent requests after failures; moving those actions behind POST removes that class almost entirely.
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悪意あるパッケージをインストールした場合：認証情報を置き換える前に実行を封じ込める
悪意あるnpmまたはPythonパッケージへの対応手順を提案する。実行と公開を止め、証拠を保全し、漏えいした認証情報をクリーンなシステムから失効させ、リポジトリ内の永続化を調べたうえで、再構築と復旧の検証を行う。
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JSON Lines: one value per line for logs, datasets and streamed responses
JSON Lines (also called NDJSON) puts one complete JSON value per line, UTF-8 without a byte order mark and newline-terminated; files can be appended, split, grepped and compressed, and a truncated stream loses only its last line. RFC 7464 JSON text sequences add a record-separator byte for recovery. Use either instead of one large JSON array whenever records are produced or consumed one at a time.
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Parallax Occlusion Mapping: Trace a Height Field With Predictable Limits
Use view-dependent height-field intersections to position surface detail, with explicit scale, sampling and silhouette limitations.
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A car or bicycle trip log: distance, duration and conditions with the measuring instrument stated
A proposed protocol for a per-trip record: name the instrument (odometer, wheel sensor with its circumference setting, or a GPS app) in the header and never mix instruments in one distance column, timestamp start and end in RFC 3339 form, log route, stops and conditions, and treat repeated-route spread as expected where gps.gov states that smartphone accuracy worsens near buildings, bridges and trees.
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Feature-flag service walk-through: rulesets, local evaluation and stable percentage rollouts
A design walk-through for a flag service: flag definitions served as one versioned ruleset per environment, SDKs that cache and evaluate locally, an evaluation context for targeting, bucketing by a stable hash so users never flip during a rollout, pre-evaluated values for untrusted clients, and reporting that finds dead flags.
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Installing and hardening the built-in OpenSSH Server on Windows Server
Add-WindowsCapability installs the OpenSSH Server feature; sshd_config lives under %ProgramData%\ssh, an administrator's authorized keys must go in administrators_authorized_keys with a locked-down ACL or the server ignores them, and DefaultShell controls what an SSH session actually runs.
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Snapshot interpolation: buffering a stable remote timeline
Render remote state between timestamped snapshots, choose a delay that tolerates network jitter, and handle missing samples without confusing interpolation with prediction.
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Pinning NuGet dependencies: PackageReference, central package management and packages.lock.json
NuGet resolves the lowest applicable version of each package at restore time, so a restore can drift when new versions or floating ranges appear; a repeatable build declares versions once in Directory.Packages.props, enables RestorePackagesWithLockFile so packages.lock.json records the full closure, commits the lock file for applications, and restores with --locked-mode in CI.
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Record assumptions as first-class data
Attach assumptions to the decisions that depend on them, with a validation check and a trigger for reconsideration.
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__slots__ and slots=True dataclasses: smaller instances with fixed attributes
Declaring __slots__ replaces the per-instance __dict__ with fixed storage, saving memory and rejecting misspelt attributes; @dataclass(slots=True) generates it from the fields but returns a new class, which breaks zero-argument super() and needs weakref_slot=True for weak references. Every base class must also declare slots.
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Build caching in CI: keys, restore fallbacks and cache poisoning
A CI cache is keyed on a hash of the lockfile with ordered fallback keys, scoped to branches with the default branch as shared parent, and is evicted by size or age; Docker layer caches must be exported and imported explicitly in CI. Caches are unsigned, so anything that can write to a trusted scope can inject code into later builds.
機械可読： JSON