docs: correct observability concepts and terminology

[killme2008]

What changed

Correct factual boundaries and terminology across the Nightly concept and reference pages.

• Make Data Model the source of truth for the shared observability table model, while treating wide events as one optional signal shape.
• Align Observability 2.0, Semantic Layer, Architecture, Key Concepts, and the glossary on Pipeline, Flow, table engines, Regions, storage, and recovery.
• Clarify update, deletion, compression, high-cardinality, object-storage, recovery, and geospatial behavior.
• Replace the old high-level architecture image with English and Chinese distributed architecture diagrams. The diagrams separate data and control paths, show storage and recovery responsibilities, mark Flownode as optional, and show that Metric Engine is built on Mito Engine.
• Describe standalone and distributed request paths without assuming object storage or unconditional failover.
• Limit Flow to incoming rows after they reach source tables instead of implying a general source-table change stream.
• Define the time index, primary key, logical and physical tables, Pipeline, Mito Engine, Metric Engine, Region, and semantic metadata consistently.
• Document the status and current limits of the experimental JSON type and the Beta JSON2 type.
• Reframe Observability 2.0 as an optional wide-event practice, with a focused Pipeline, SQL, and Flow mapping.
• Remove remaining Nightly wording that classifies GreptimeDB or GreptimeDB Enterprise as a time-series database. Keep TSDB terms where they describe a protocol, comparison, workload, glossary term, or search keyword.
• Scope the real-time and historical analysis diagram to distributed deployments backed by object storage, with workload isolation marked as Enterprise.
• Rename the Observability 2.0 navigation entry without changing its URL.

Dependency

• Base: main
• docs: clarify Observability 2.0 data model #2739, docs: refresh observability concepts foundation #2740, and docs: add Observability 2.0 model diagrams #2742 are merged and included in main.

Scope

• Documentation versions: Nightly only; released versions are unchanged
• Languages: English and Chinese

Verification

• git diff --check
• npx --yes markdownlint-cli@0.45.0 --config .markdownlint.yaml <changed files>
• typos --config .typos.toml <changed files>
• xmllint --noout <changed SVG files>
• Rendered and inspected the changed English and Chinese SVG files
• pnpm build
• DOC_LANG=zh pnpm build
• DOC_LANG=en pnpm check:links
• DOC_LANG=zh pnpm check:links
• Reviewed the complete diff for versioned docs, generated files, and lockfile changes

Both strict link checks and both locale builds completed successfully.

Checklist

• I verified the content against the applicable GreptimeDB version.
• I updated the relevant documentation versions and languages, or explained why not.
• I checked changed links and anchors.
• I updated and verified the Nightly English and Chinese navigation labels.

[cloudflare-workers-and-pages]

Deploying greptime-docs with    Cloudflare Pages

Latest commit:	f76d9b7
Status:	✅  Deploy successful!
Preview URL:	https://a7dd555c.greptime-docs.pages.dev
Branch Preview URL:	https://codex-refresh-concepts-facts.greptime-docs.pages.dev

View logs

[Copilot]

Pull request overview

Updates Nightly (EN+ZH) documentation to correct and align observability-related concepts and terminology (Pipeline/Flow, table engines, Regions, storage/recovery responsibilities), and refreshes supporting architecture/flow diagrams to match the clarified boundaries.

Changes:

• Reframes Observability 2.0 as an optional wide-event practice and moves “shared observability table model” framing into the Data Model pages (EN+ZH), with consistent definitions across Concepts/Glossary/FAQ.
• Replaces/updates multiple SVG diagrams (EN+ZH) to reflect distributed vs standalone paths, object storage scope, and responsibilities (WAL vs persistent files vs Metasrv state).
• Renames the Concepts sidebar entry label for the Observability 2.0 page (URL unchanged) and updates the corresponding ZH i18n sidebar label.

Reviewed changes

Copilot reviewed 29 out of 35 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
static/shared-system-realtime-historical.zh.svg	Updates diagram text/description to scope the “shared system” story to distributed + object storage and clarify Enterprise isolation.
static/shared-system-realtime-historical.svg	Same as above for English.
static/optional-pipeline-flow.zh.svg	Clarifies Flow’s relationship to incoming event rows (continuous aggregation wording).
static/optional-pipeline-flow.svg	Same as above for English.
static/greptimedb-distributed-architecture.zh.svg	Adds a new distributed architecture diagram (ZH) separating data/control paths and recovery responsibilities.
static/greptimedb-distributed-architecture.svg	Adds a new distributed architecture diagram (EN) separating data/control paths and recovery responsibilities.
sidebars.ts	Renames the Concepts sidebar label for the Observability 2.0 page (URL unchanged).
i18n/zh/docusaurus-plugin-content-docs/current/user-guide/deployments-administration/performance-tuning/design-table.md	Removes TSDB framing in distributed table misconceptions; tightens wording.
i18n/zh/docusaurus-plugin-content-docs/current/user-guide/deployments-administration/manage-data/basic-table-operations.md	Rewords TIME INDEX explanation to “exactly one time index” without TSDB classification.
i18n/zh/docusaurus-plugin-content-docs/current/user-guide/concepts/why-greptimedb.md	Aligns “shared system” section with object-storage distributed scope; adjusts diagram usage.
i18n/zh/docusaurus-plugin-content-docs/current/user-guide/concepts/semantic-layer.md	Clarifies purpose/mechanics of greptime.semantic.* metadata and protocol-specific limits.
i18n/zh/docusaurus-plugin-content-docs/current/user-guide/concepts/overview.md	Updates deep-dive link label to the new Observability 2.0 wording.
i18n/zh/docusaurus-plugin-content-docs/current/user-guide/concepts/observability-2.md	Reframes page around wide events as optional practice and Pipeline/SQL/Flow staging.
i18n/zh/docusaurus-plugin-content-docs/current/user-guide/concepts/key-concepts.md	Redefines core concepts (time index, PK, Region, engines, Pipeline/Flow) consistently.
i18n/zh/docusaurus-plugin-content-docs/current/user-guide/concepts/features-that-you-concern.md	Updates FAQ answers for update/delete/TTL/high-cardinality/DR/geo/JSON (JSON vs JSON2).
i18n/zh/docusaurus-plugin-content-docs/current/user-guide/concepts/data-model.md	Establishes Data Model as the “source of truth” and adds the shared model diagram.
i18n/zh/docusaurus-plugin-content-docs/current/user-guide/concepts/architecture.md	Replaces high-level image with new diagram; clarifies component roles and request paths.
i18n/zh/docusaurus-plugin-content-docs/current/reference/glossary.md	Updates glossary definitions to match revised concepts (engines, Region, WAL, JSON2, etc.).
i18n/zh/docusaurus-plugin-content-docs/current/enterprise/overview.md	Repositions Enterprise overview around deployment/security/availability/ops capabilities.
i18n/zh/docusaurus-plugin-content-docs/current/contributor-guide/datanode/data-persistence-indexing.md	Tightens inverted-index explanation wording (ZH).
i18n/zh/docusaurus-plugin-content-docs/current.json	Updates the ZH sidebar label key/value to match the renamed English label.
docs/user-guide/deployments-administration/performance-tuning/design-table.md	Removes TSDB framing in distributed table misconceptions; tightens wording.
docs/user-guide/deployments-administration/manage-data/basic-table-operations.md	Rewords TIME INDEX explanation to “exactly one time index” without TSDB classification.
docs/user-guide/concepts/why-greptimedb.md	Aligns “shared system” section with object-storage distributed scope; adjusts diagram usage.
docs/user-guide/concepts/semantic-layer.md	Clarifies purpose/mechanics of greptime.semantic.* metadata and protocol-specific limits.
docs/user-guide/concepts/overview.md	Updates deep-dive link label to the new Observability 2.0 wording.
docs/user-guide/concepts/observability-2.md	Reframes page around wide events as optional practice and Pipeline/SQL/Flow staging.
docs/user-guide/concepts/key-concepts.md	Redefines core concepts (time index, PK, Region, engines, Pipeline/Flow) consistently.
docs/user-guide/concepts/features-that-you-concern.md	Updates FAQ answers for update/delete/TTL/high-cardinality/DR/geo/JSON (JSON vs JSON2).
docs/user-guide/concepts/data-model.md	Establishes Data Model as the “source of truth” and adds the shared model diagram.
docs/user-guide/concepts/architecture.md	Replaces high-level image with new diagram; clarifies component roles and request paths.
docs/reference/glossary.md	Updates glossary definitions to match revised concepts (engines, Region, WAL, JSON2, etc.).
docs/getting-started/installation/overview.md	Removes “time series database” wording from cluster install entry.
docs/enterprise/overview.md	Repositions Enterprise overview around deployment/security/availability/ops capabilities.
docs/contributor-guide/datanode/data-persistence-indexing.md	Tightens inverted-index explanation wording (EN).

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[v0y4g3r]

LGTM