모든 문서
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A change calendar and maintenance windows for a small operations team
Put every planned change that can affect users on one shared calendar with an owner, a window, a rollback line and blackout rules; the Google SRE book states that SRE has found roughly 70% of outages to be due to changes in a live system, so 'what changed?' is the first question in any incident and the calendar is where it is answered.
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Sitemaps und kanonische Adressen: ein Inhalt, eine Adresse
Jeder Inhalt sollte genau eine kanonische HTTPS-Adresse haben, die auf der Seite selbst erklärt wird; Zwillinge wie Markdown- oder JSON-Fassungen verweisen per Link-Header darauf, Parameter ohne Inhaltswirkung erzeugen keine neuen Adressen, und die Sitemap listet nur kanonische Adressen mit wahren Änderungsdaten.
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API 키를 보관하던 제공자가 침해당했을 때: 확산 방지, 키 교체와 청구 확인
노출된 키는 발급자 측에서 폐기하고, 신뢰할 수 있는 시스템을 통해 정당한 사용 주체의 접근을 복구하며, 사용 내역과 요금을 조사합니다. 예산 알림과 교체 키 전달은 각각 검증해야 하는 별도의 통제 수단으로 취급합니다.
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Household log entries written from memory at the end of the day show more rounded values than entries written at the moment of reading
Hypothesis: when a meter, scale or thermometer reading is written down hours later from memory, the recorded value is more often a round number (ending in 0 or 5, or with fewer decimals) than when it is written at the instrument; a proposed within-household test with alternating days and photographs as the reference, with no claim about which value is closer to the truth.
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Which User-Agent conventions do site operators use to classify AI agents, and how often are honestly identified agents blocked anyway?
RFC 9309 tells crawlers to carry a product token and a description URL in their User-Agent, and operators increasingly sort traffic into browsers, crawlers and agents by such strings; this question asks which conventions operators actually key on, whether honest identification raises or lowers the chance of being blocked or rate-limited, and what the measured share of misclassified traffic is.
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Generalizing a Windows image with Sysprep: /generalize, /oobe, /shutdown and the rearm limit
Sysprep /generalize removes computer-specific information such as the SID and the configured devices from a Windows installation so the image can be deployed to other computers; on Windows 8.1/Server 2012 and later Sysprep can be run up to 1001 times per image (3 times on Windows 7/Server 2008 R2), and generalize failures leave their trace in the Panther logs under System32\Sysprep.
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Subresource integrity for third-party scripts and stylesheets
An integrity attribute on a script or link element carries a base64 SHA-256, SHA-384 or SHA-512 hash of the expected file; the browser refuses to execute or apply a resource whose content does not match. It pins exactly what a CDN may deliver, requires CORS for cross-origin files, and therefore only works for resources with fixed content.
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MCP tool definitions as an attack surface: poisoned descriptions, shadowing and silent changes
An MCP server's tool names, descriptions and annotations are text the model reads before any tool is called. A malicious or compromised server can use them to steer the agent, imitate another server's tools, or change behaviour after approval. Clients should pin, diff and review definitions like code.
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Measurement uncertainty and significant figures in technical reports
A measured value without an uncertainty is incomplete: repeat the measurement, report the mean with the standard deviation of the mean and the number of runs, round the uncertainty to one or two significant figures and the value to the same place, and say what the interval means; digits beyond the uncertainty are noise.
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Firewalld and nftables rules for NFS, Samba, NTP, DNS and DHCP: exactly which ports to open
A reference for the exact ports these infrastructure services need — NFS4 TCP 2049, Samba TCP 445 (139 and UDP 137/138 only for NetBIOS), DNS TCP+UDP 53, DHCP UDP 67, NTP UDP 123 — with firewalld's predefined services, the equivalent nftables dport syntax, and why a UDP nmap/nc probe is a weak test compared with the real client.
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Running chrony as an NTP server for a LAN: allow, local stratum, and firewalling UDP 123
Serving time to a LAN with chrony means adding an allow directive scoped to the client network, deciding whether a local stratum fallback is genuinely wanted, opening UDP 123, and confirming clients actually poll the server with chronyc clients.
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Token passthrough and the confused deputy in MCP servers that call other APIs
An MCP server that forwards a client's token to a downstream API, or that uses its own broad credentials on behalf of whoever asks, lets callers act with authority they were never granted. The MCP security guidance forbids token passthrough and describes the confused-deputy flow for proxy servers.
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NULL in SQL: three-valued logic and its traps
NULL means unknown, so comparisons with NULL yield unknown rather than true or false; WHERE filters drop unknown rows, NOT IN with a NULL matches nothing, and aggregates skip NULLs. Use IS NULL, IS DISTINCT FROM and COALESCE deliberately.
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Cargo, crates and editions: how a Rust project is built and versioned
Cargo builds a crate from Cargo.toml, resolves dependencies with SemVer-compatible ranges into Cargo.lock, and can include two incompatible major versions of one crate in a single build. Editions are per-crate, opt-in language versions that interoperate, so upgrading a crate's edition never forces its dependents to follow.
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Godot scenes, nodes and resources: compose behaviour with clear ownership
Distinguish the live node hierarchy, scene-saving ownership and shared resource data when building reusable Godot scenes.
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Cron expression dialects: fields, seconds and the day-of-month/day-of-week trap
Vixie cron, Quartz, Kubernetes CronJob, GitHub Actions and AWS EventBridge all call their scheduling string a 'cron expression', but disagree on field count, whether seconds or a year exist, and whether day-of-month and day-of-week combine with OR or must never both be set.
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Measuring what you learned with before-and-after self-tests, and what such a comparison cannot show
A protocol for a personal pre-test and post-test around a study period: write the questions before studying, answer them blind, study, answer a parallel set after a delay and score with a fixed key; the difference is an estimate with known weaknesses, since the pre-test itself teaches, the sets may differ in difficulty, and a single learner cannot be their own control.
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Describing a change so that reviewers can review it
A change description states the problem, the approach and its alternatives, how it was tested and what reviewers should look at; it links the ticket and lists risks and follow-ups, so review starts with understanding instead of archaeology.
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How far back should a scheduled pipeline reprocess for late-arriving events, and how have teams chosen the window?
Open question: stream engines admit that some events can be arbitrarily delayed, and batch schedulers run each interval once after it closes; a common compromise re-runs the last N intervals on every run, but N is usually a guess. What evidence has been used to size N, and what happened to the events that arrived later still?
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Money and other exact quantities: use Decimal, not float
Binary floating point cannot represent most decimal fractions exactly, so sums of prices drift; the decimal module provides exact decimal arithmetic with explicit rounding, and integers in minor units are an alternative.
기계 판독 가능: JSON