MongoDB Architecture and Features

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1. MongoDB Architecture

MongoDB follows a distributed and scalable architecture designed for high availability and performance.

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1.1 Basic Components

1. Database

• Container for collections

2. Collection

• Group of documents

• Similar to a table in RDBMS

3. Document

• Stored in BSON format

• Contains key–value pairs

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1.2 MongoDB Server (mongod)

• Core database process

• Handles data storage, queries, and indexing

• Manages replication and sharding

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1.3 Replica Set Architecture

A replica set is a group of MongoDB servers that maintain the same data.

Components:

• Primary node – Handles write operations

• Secondary nodes – Replicate data from primary

• Arbiter (optional) – Helps in election

Benefits:

• High availability

• Automatic failover

• Data redundancy

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1.4 Sharded Cluster Architecture

Used for horizontal scalability.

Components:

• Shards – Store actual data

• Config servers – Store metadata

• mongos – Query router

Benefits:

• Handles very large datasets

• Load balancing

• High performance

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2. MongoDB Features

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1. Schema Flexibility

• No fixed schema

• Easy to modify data structure

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2. High Scalability

• Supports horizontal scaling

• Sharding distributes data across nodes

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3. High Availability

• Replica sets provide fault tolerance

• Automatic failover support

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4. Indexing

• Supports single-field and compound indexes

• Improves query performance

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5. Rich Query Language

• JSON-based queries

• Supports filtering, sorting, and aggregation

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6. Aggregation Framework

• Processes data using pipelines

• Useful for analytics and reporting

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7. Transactions

• Supports multi-document ACID transactions

• Useful for complex operations

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8. Security

• Authentication and authorization

• Data encryption

• Role-based access control

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3. Advantages of MongoDB Architecture

• High performance

• Fault tolerant

• Easy to scale

• Suitable for distributed applications