Saga Account

Account service of my saga pattern implementation.

Features:

• High performance gRPC authentication
• JWT token management
• Caching middleware proxy compatible with repository interface
• Local + Redis cache
• Request coalescing to prevent cache avalanche
• Prometheus metrics
• Distributed tracing with OpenTelemetry
  • HTTP server
  • gPRC server
• Comprehensive application struture with domain-driven design (DDD), decoupling service implementations from configurations and transports
• Compile-time dependecy injection using wire
• Graceful shutdown
• Unit testing and continuous integration using Drone CI

Usage

Setup githooks:

git config core.hooksPath githooks

Build from source:

make build

Start the service:

DB_DSN="ming:password@tcp(accountdb:3306)/account?charset=utf8mb4&parseTime=True&loc=Local" \
REDIS_ADDRS=redis-node1:7000,redis-node2:7001,redis-node3:7002,redis-node4:7003,redis-node5:7004,redis-node6:7005 \
REDIS_PASSWORD=myredispassword \
JWT_ACCESS_TOKEN_EXPIRE_SECOND=10800 \
JWT_REFRESH_TOKEN_EXPIRE_SECOND=86400 \
JAEGER_URL=http://jaeger:14268/api/traces \
./server

Test locally:

DB_DSN="ming:password@tcp(<mysql-host>:3306)/account?charset=utf8mb4&parseTime=True&loc=Local" \
make test

• DB_DSN: MySQL connection DSN.
• REDIS_ADDRS: Redis seed server addresses
• JWT_ACCESS_TOKEN_EXPIRE_SECOND: access token expiration duration (second)
• JWT_REFRESH_TOKEN_EXPIRE_SECOND: refresh token expiration duration (second)

Running in Docker

See docker-compose example for details.

Exported Metrics

Metric	Description	Labels
account_http_request_duration_seconds (account_http_request_duration_seconds_count, account_http_request_duration_seconds_bucket, account_http_request_duration_sum)	A Prometheus histogram. Records the latency of the HTTP requests.	code, handler, method
account_http_requests_inflight	A Prometheus gauge. Records the number of inflight requests being handled at the same time.	code, handler, method
account_http_response_size_bytes (account_http_response_size_bytes_count, account_http_response_size_bytes_bucket, account_http_response_size_bytes_sum)	A Prometheus histogram. Records the size of the HTTP responses.	handler