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Cloud Monitor:Introduction to EntityStore

Last Updated:Oct 23, 2025

Overview

EntityStore is the unified storage engine for the UModel system. It stores and manages core metadata in the observability realm, such as UModel metadata, entity data, and entity relationship data. EntityStore provides high-performance data storage and query capabilities for observability analysis.

Core concepts

Before you explore EntityStore, it is important to understand the following core concepts, which are often confused:

Concept

Definition

Analogy

Example

UModel

A complete knowledge graph system

The entire database schema

A complete modeling system that includes all APM, K8s, and cloud resources

EntitySet

An entity type definition in the knowledge graph

A table schema definition in a database

apm.service (APM service type definition)

Entity

A specific entity instance

A specific record in a database

user-service-v1.2.3 (A specific service instance)

EntitySetLink

A relationship definition between entities

A relationship type definition in a Graph Database

service_runs_on_pod (A service runs on a pod)

EntityRelations

A relationship instance between entities

A relationship instance in a Graph Database

user-service -> web-pod-123 (A service runs on a pod)

Detailed relationships

UModel (knowledge graph)

  • Function: Defines the modeling standards for the entire observability realm.

  • Includes: All EntitySet definitions, field specifications, relationship types, and more.

  • Characteristic: A schema-level definition that describes what types of entities can exist.

EntitySet (entity type)

  • Function: Defines the structure and property standards for a class of entities.

  • Includes: Field definitions, primary keys, indexes, validation rules, and more.

  • Characteristic: Similar to a class definition, it specifies the properties that an instance must have.

Entity (entity instance)

  • Function: A specific business object instance.

  • Includes: Specific property values and status information.

  • Characteristic: Represents real runtime data.

How they work together

UModel (knowledge graph)
├── EntitySet: apm.service (type definition)
│   ├── Entity: user-service (instance 1)
│   ├── Entity: payment-service (instance 2)
│   └── Entity: order-service (instance 3)
├── EntitySet: k8s.pod (type definition)
│   ├── Entity: web-pod-123 (instance 1)
│   └── Entity: api-pod-456 (instance 2)
└── EntitySetLink: service_runs_on_pod (relationship definition)
    ├── Relation: user-service -> web-pod-123
    └── Relation: payment-service -> api-pod-456

EntityStore architecture

Core components

EntityStore uses a layered architecture that includes the following core components:

┌─────────────────────────────────────────────────────┐
│                  Query Layer                        │
│  ┌─────────────┐ ┌─────────────┐ ┌─────────────┐    │
│  │   USearch   │ │ Graph Query │ │ UModel Query│    │
│  │(Entity Retrieval)│ │(Relationship Query)│ │(Metadata Query) │    │
│  └─────────────┘ └─────────────┘ └─────────────┘    │
└─────────────────────────────────────────────────────┘
                           │
┌─────────────────────────────────────────────────────┐
│                Storage Engine                       │
│  ┌─────────────┐ ┌─────────────┐ ┌─────────────┐    │
│  │    UModel   │ │   Entity    │ │    Topo     │    │
│  │  (Metastore)  │ │(Entity Storage) │ │(Relationship Storage)│    │
│  └─────────────┘ └─────────────┘ └─────────────┘    │
└─────────────────────────────────────────────────────┘

SLS Logstore assets

EntityStore uses Simple Log Service (SLS) Logstores to write and consume data. When you create an EntityStore, the following Logstore assets are also created:

  • ${workspace}__entity: Used to write entity data.

  • ${workspace}__topo: Used to write relationship data.

Features

1. Multi-pattern query support

USearch (entity retrieval)

  • Full-text index: Supports fuzzy searches across multiple fields.

  • Term query: Supports exact matches based on ID or properties.

  • Aggregation analysis: Provides statistics and grouping features.

UModel Query (metadata query)

  • Schema query: Retrieves EntitySet definitions.

  • Relationship definition query: Retrieves EntitySetLink configurations.

  • Graph computing: Performs association analysis based on UModel metadata.

Graph Query (relationship query)

  • Path query: Analyzes multi-hop relationship paths.

  • Neighbor query: Analyzes adjacent relationships of an entity.

  • Custom query: Recognizes custom topology patterns.

2. Dynamic lifecycle for entity topology

  • Dynamic lifecycle: Entities and relationships have a dynamic lifecycle, which lets you set their expiration and deletion times.

  • Point-in-time recovery: You can restore the state of entities and relationships to any point in time, which is useful for troubleshooting.

  • Query performance optimization: A dynamic entity replacement mechanism ensures query performance across different epochs.

3. Write pattern support

  • Incremental writes: Real-time updates based on events.

  • Full writes: Periodic and complete data synchronization.

  • Lifecycle management: Supports Create, Update, Expire, Delete, and Revise operations.