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Fixes #29043 with the following docs changes: - docs/dev/system-keyspaces.md: Added a new file that documents all keyspaces created internally Closes scylladb/scylladb#29044
68 lines
3.2 KiB
Markdown
68 lines
3.2 KiB
Markdown
# System Keyspaces Overview
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This page gives a high-level overview of several internal keyspaces and what they are used for.
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## Table of Contents
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- [system_replicated_keys](#system_replicated_keys)
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- [system_distributed](#system_distributed)
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- [system_distributed_everywhere](#system_distributed_everywhere)
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- [system_auth](#system_auth)
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- [system](#system)
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- [system_schema](#system_schema)
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- [system_traces](#system_traces)
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- [system_audit/audit](#system_auditaudit)
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## `system_replicated_keys`
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Internal keyspace for encryption-at-rest key material used by the replicated key provider. It stores encrypted data keys so nodes can retrieve the correct key IDs when reading encrypted data.
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This keyspace is created as an internal system keyspace and uses `EverywhereStrategy` so key metadata is available on every node. It is not intended for user data.
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## `system_distributed`
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Internal distributed metadata keyspace used for cluster-wide coordination data that is shared across nodes.
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In practice, it is used for metadata such as:
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- materialized view build coordination state
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- CDC stream/timestamp metadata exposed to clients
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- service level definitions used by workload prioritization
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This keyspace is managed by Scylla and is not intended for application tables.
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It is created as an internal keyspace (historically with `SimpleStrategy` and RF=3 by default).
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## `system_distributed_everywhere`
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Legacy keyspace. It is no longer used.
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## `system_auth`
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Legacy auth keyspace name kept primarily for compatibility.
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Auth tables have moved to the `system` keyspace (`roles`, `role_members`, `role_permissions`, and related auth state). `system_auth` may still exist for compatibility with legacy tooling/queries, but it is no longer where current auth state is primarily stored.
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## `system`
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This keyspace is local one, so each node has its own, independent content for tables in this keyspace. For some tables, the content is coordinated at a higher level (RAFT), but not via the traditional replication systems (storage proxy).
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See the detailed table-level documentation here: [system_keyspace](system_keyspace.md)
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## `system_schema`
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This keyspace is local one, so each node has its own, independent content for tables in this keyspace. All tables in this keyspace are coordinated via the schema replication system.
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See the detailed table-level documentation here: [system_schema_keyspace](system_schema_keyspace.md)
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## `system_traces`
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Internal tracing keyspace used for query tracing and slow-query logging records (`sessions`, `events`, and related index/log tables).
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This keyspace is written by Scylla's tracing subsystem for diagnostics and observability. It is operational metadata, not user application data (historically created with `SimpleStrategy` and RF=2).
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## `system_audit`/`audit`
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Internal audit-logging keyspace used to persist audit events when table-backed auditing is enabled.
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Scylla's audit table storage is implemented as an internal audit keyspace for audit records (for example, auth/admin/DCL activity depending on audit configuration). In current code this keyspace is named `audit`, while operational material may refer to it as its historical name (`system_audit`). It is intended for security/compliance observability, not for application data.
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