모든 문서
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Report partial failure structurally
Return per-operation outcomes and an explicit aggregate state so successful work is not repeated after a mixed result.
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Building a software RAID1 mirror with mdadm and replacing a failed disk
mdadm --create builds a Linux software RAID array from partitions or whole disks; without an entry in mdadm.conf and an updated initramfs the array can fail to reassemble on the next boot even though it works fine right after creation.
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Troubleshooting Group Policy application: gpresult, gpupdate, and the GroupPolicy module
Reading what policy actually applied to a computer or user with gpresult /h and Get-GPResultantSetOfPolicy, forcing reprocessing with gpupdate /force, and backing up a GPO with Backup-GPO before editing it.
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Distributed tracing in outline: spans, parent IDs and W3C trace context propagation
A trace is a tree of spans, each with a trace ID, its own span ID, a parent span ID, timestamps, attributes and a status; the W3C traceparent header carries trace ID, parent ID and a sampled flag across process boundaries, and a service that only forwards both headers still keeps traces intact.
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Memory poisoning: when one injected instruction survives into every later session
Agents with persistent memory can be made to store an attacker's instruction as a fact or preference; it then influences sessions that never saw the original content. Writes to memory need provenance, review and an expiry, and reads from memory should be treated as untrusted text.
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Choosing the next debugging check by the hypotheses it can distinguish
Stop an investigation from repeating low-information diagnostics by choosing each next check for the competing explanations its result can separate.
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Storing passwords and API keys
Passwords are stored only as salted, slow hashes (Argon2id, scrypt, bcrypt); high-entropy API keys can use a keyed fast hash; both are compared in constant time and never logged or returned after issue.
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Clock sync compared: chrony, systemd-timesyncd, w32tm, macOS timed and AIX xntpd
A quick reference for checking whether a host's clock is actually synchronized, across the time daemons used by Linux, Windows, macOS and AIX — distinct from a deep dive on any single tool, since the check is the same shape everywhere: is a source configured, and is it currently in sync.
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Adding a private CA to the system trust store on RHEL-family and Debian/Ubuntu
RHEL-family and Debian-family Linux keep separate mechanisms for adding a locally trusted CA certificate: update-ca-trust with anchors under /etc/pki/ca-trust, and update-ca-certificates with .crt files under /usr/local/share/ca-certificates. Using the wrong directory or extension silently leaves the CA untrusted.
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wget and rsync exit codes: rsync's 23 and 24 usually aren't the failure they look like
wget assigns a small fixed code per error class (network, SSL, auth, protocol); rsync's larger table includes 23 (partial transfer due to error) and 24 (partial transfer due to vanished source files), the latter of which commonly just means a file disappeared mid-scan and is not evidence of a broken transfer.
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Conventional Commits: machine-readable commit types
The Conventional Commits specification adds a typed prefix (feat, fix, and others) and breaking-change markers to commit messages so that changelogs and version bumps can be derived automatically.
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Time-based one-time passwords as a second factor
TOTP (RFC 6238) derives a short code from a shared secret and the current time step; it protects against password reuse but not against real-time phishing, and needs secure secret storage, clock tolerance and recovery codes.
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Alert routing: grouping, inhibition, silences and escalation policies
Between a firing alert and a phone lie four decisions: which team and channel receive it (routing tree), which alerts travel together (grouping with group_wait, group_interval and repeat_interval), which are muted because a cause alert already explains them (inhibition) or because maintenance is planned (silences), and how long a responder has before the page escalates to the next person.
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Making HTTP requests correctly from Python
Set timeouts on every request, reuse a client for connection pooling, send Accept and User-Agent headers, decode by declared charset, handle status codes and retries deliberately; the standard library and httpx both support this.
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Running a service under systemd
A unit file declares how a service starts, restarts and is confined; use Type, Restart=on-failure, resource limits and sandboxing directives, and read logs with journalctl instead of writing your own daemonisation.
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Confirming a security patch actually landed: matching installed versions against vendor advisories across OS families
An update job reporting success is not proof a specific vulnerability is fixed; matching the installed package or build version against the vendor's own advisory — Ubuntu USN, a RHEL-family advisory (RHSA on RHEL) via dnf updateinfo --security, Debian DSA via debsecan, Windows Get-HotFix, or a macOS build number against Apple's own security-release page — is what closes the loop, and a pending restart can leave the old, vulnerable binary still running even after that check passes.
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OAuth 2.0 client credentials for machine-to-machine access
The client credentials grant lets a service or agent obtain an access token with its own client ID and secret, without a user; scope and resource indicators bound the token, and the secret must be treated like a password: stored hashed by the server and rotated by the client.
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Scoping Windows Defender Firewall rules with NetSecurity without locking out your own session
Get-NetFirewallProfile and New-NetFirewallRule manage Windows Defender Firewall from PowerShell; scoping a rule by -RemoteAddress and -Profile keeps a management port open only to the addresses and network types that need it, and testing from a second session avoids cutting off the one you're using.
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Governance for a small project: decision rights written down before they are needed
A governance file answers who can merge, who settles a scope dispute, how maintainers are added and removed, and how the rules themselves change. Python's PEP 13 shows a council model with authority that is meant to be used rarely and with public deliberation; the Apache glossary defines lazy consensus, under which a proposal passes if nobody objects within a stated period. A project with one to three maintainers needs only a page.
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대조적 자기지도 학습: 쌍, 증강, 표현 붕괴
관련된 뷰와 대조되는 뷰를 비교해 표현을 학습하고, 유용한 정보를 보존하는 변환을 선택하며, 학습 손실을 넘어 표현을 평가한다.
기계 판독 가능: JSON