mongodb/mongo

How mongodb/mongo works

MongoDB is a database server (mongod) with a sharding router (mongos). The README’s user workflow is a client connecting to a running server; it also describes a single-server setup. Sampled source shows internal query-settings management, hybrid-search pipeline construction, query-analysis command execution, and oplog visibility coordination. The source excerpts do not establish the full request-routing or query-execution path, so those connections are not expanded here. Some nodes represent broader runtime subsystems supported by the repository tree, not inspected implementation details.

Main entry points: query_settings_service.cpp Query settings service · storage_oplog_manager.cpp Oplog visibility · query_analysis_client.cpp Query analysis client · pipeline Aggregation pipelines

Components 16

Client entry

Database server
Sharding router

Query processing

Query execution src/mongo/db/query
Aggregation pipelines src/mongo/db/pipeline
Hybrid search builder src/mongo/db/pipeline/hybrid_search_pipeline_builder.cpp
Query settings service src/mongo/db/query/query_settings/query_settings_service.cpp

Cluster services

Query analysis client src/mongo/s/query_analysis_client.cpp
Replication coordination src/mongo/db/repl

Storage and primitives

Storage engine src/mongo/db/storage
Oplog visibility src/mongo/db/storage/storage_oplog_manager.cpp
Record store src/mongo/db/storage/record_store.h
BSON documents src/mongo/bson/bsonobj.h
BSON types src/mongo/bson/bsontypes.h
Structured logging src/mongo/logv2/log.h
Error handling src/mongo/util/assert_util.h

Other components

MongoDB client

Connections 12

MongoDB client → Database server: connects to
MongoDB client → Sharding router: routes through
Sharding router → Database server: dispatches requests
Query settings service → Aggregation pipelines: builds contexts src/mongo/db/query/query_settings/query_settings_service.cpp
Query settings service → BSON documents: parses commands src/mongo/db/query/query_settings/query_settings_service.cpp
Hybrid search builder → Aggregation pipelines: constructs stages src/mongo/db/pipeline/hybrid_search_pipeline_builder.cpp
Query analysis client → Replication coordination: checks primary src/mongo/s/query_analysis_client.cpp
Query analysis client → Database server: runs local commands src/mongo/s/query_analysis_client.cpp
Oplog visibility → Record store: reads oplog src/mongo/db/storage/storage_oplog_manager.cpp
Oplog visibility → Storage engine: tracks visibility src/mongo/db/storage/storage_oplog_manager.cpp
Oplog visibility → Structured logging: logs visibility src/mongo/db/storage/storage_oplog_manager.cpp
Query settings service → Structured logging: logs lookup failures src/mongo/db/query/query_settings/query_settings_service.cpp

More C++ diagrams: notepad-plus-plus/notepad-plus-plus · ossrs/srs · dmlc/xgboost · ml-explore/mlx · taichi-dev/taichi

Drawn by GitDiagram on October 27, 2026 from the repository's file tree, README and source files. Read as Markdown ·