https://www.youngju.dev/blog 천천히 올바르게. AI Researcher & DevOps Engineer Youngju's blog. GPU/CUDA, LLM, MLOps, Kubernetes AI workloads, and data engineering — plus mindset essays on confidence, routines, health, and sport psychology. ko fjvbn2003@gmail.com (Youngju Kim) fjvbn2003@gmail.com (Youngju Kim) Sun, 09 Aug 2026 00:00:00 GMT https://www.youngju.dev/blog/architecture/2026-08-09-data-residency-is-a-replication-topology.en https://www.youngju.dev/blog/architecture/2026-08-09-data-residency-is-a-replication-topology.en Using the document Fastmail published when it opened an EU data region on August 3, 2026 as a textbook, this post lays out why the location of your data is not settled by picking a region once. The primary copy, the replicas, the disaster backup, globally replicated metadata, logs, third-party integrations, and the fallback path during an outage can each sit somewhere different, and in practice they do. Fastmail states that the replica of an EU account is in the US, that backups are in Philadelphia, and that logs are consolidated in the US, and it says that because it is an Australian company it will respond the same way to lawful requests regardless of where the data sits. Taking that level of disclosure as a baseline, here are the questions to put to a vendor and the checklist to turn back on your own system. Sun, 09 Aug 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) architecturedata-residencygdprreplicationcompliancesovereignty https://www.youngju.dev/blog/architecture/2026-08-09-data-residency-is-a-replication-topology.ja https://www.youngju.dev/blog/architecture/2026-08-09-data-residency-is-a-replication-topology.ja Fastmailが2026年8月3日にEUデータリージョンを開くにあたって公開した文書を教材にして、データの所在地がなぜリージョンの選択ひとつで決まらないのかを整理します。主コピー、レプリカ、災害用バックアップ、全世界に複製されるメタデータ、ログ、サードパーティ連携、そして障害時のフォールバック経路は、それぞれ別の場所を持ちうるし実際に持っています。FastmailはEUアカウントのレプリカが米国にあり、バックアップはフィラデルフィアにあり、ログは米国に統合されると明記し、自社がオーストラリア法人であるためデータの位置と関係なく適法な要請には同じように対応すると述べています。この開示水準を基準線にして、ベンダーに問うべき質問と自分のシステムに向け直す点検項目を提示します。 Sun, 09 Aug 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) architecturedata-residencygdprreplicationcompliancesovereignty https://www.youngju.dev/blog/architecture/2026-08-09-data-residency-is-a-replication-topology https://www.youngju.dev/blog/architecture/2026-08-09-data-residency-is-a-replication-topology Fastmail이 2026년 8월 3일 EU 데이터 리전을 열면서 공개한 문서를 교재 삼아, 데이터 소재지가 왜 리전 선택 한 번으로 결정되지 않는지 정리합니다. 주 사본, 복제본, 비상 백업, 전역 복제되는 메타데이터, 로그, 서드파티 연동, 그리고 장애 시 폴백 경로는 각각 다른 위치를 가질 수 있고 실제로 갖습니다. Fastmail은 EU 계정의 복제본이 미국에 있고 백업은 필라델피아에 있으며 로그는 미국에 통합된다고 명시하고, 자사가 호주 법인이므로 데이터 위치와 무관하게 적법한 요청에 동일하게 대응한다고 밝힙니다. 이 공개 수준을 기준선 삼아 벤더에게 물어야 할 질문과 자기 시스템에 돌려볼 점검 항목을 제시합니다. Sun, 09 Aug 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) architecturedata-residencygdprreplicationcompliancesovereignty https://www.youngju.dev/blog/architecture/2026-08-09-data-residency-is-a-replication-topology.zh https://www.youngju.dev/blog/architecture/2026-08-09-data-residency-is-a-replication-topology.zh 本文以 Fastmail 在 2026 年 8 月 3 日开放欧盟数据区时公开的文档为教材，讲清楚数据所在地为什么不是选一次区域就能定下来的。主副本、副本、灾备备份、全局复制的元数据、日志、第三方集成，以及故障时的回退路径，各自可以在不同的位置 —— 而且实际上就在不同的位置。Fastmail 明确写出欧盟账号的副本在美国、备份在费城、日志汇总在美国，并说明自家是澳大利亚法人，因此无论数据在哪里，对合法请求的响应都一样。以这份披露程度作为基线，本文给出该向供应商提出的问题，以及可以回过头检视自家系统的清单。 Sun, 09 Aug 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) architecturedata-residencygdprreplicationcompliancesovereignty