Saga Product

Transaction services of my saga pattern implementation, including product, order, payment and orchestrator.

Features:

Entirely event-driven
Idempotency for all transactions
Stateless saga orchestrator making transactions scalable
Sonyflake distributed unique ID generator
Redis cache for fast data retrieval
Bloom/Cuckoo filters for preventing cache penatration
Prometheus metrics
Distributed tracing with OpenTelemetry
- HTTP server
- gRPC server
- gPRC client
- Event handlers
Four microservices in a monorepo and compiled to a single binary, minimizing deployment efforts
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

See docker-compose example for details on how to start each service.

Metric	Description	Labels
APP_pubsub_subscriber_messages_received_total	A Prometheus Counter. Counts the number of messages obtained by the subscriber.	`acked` ("acked" or "nacked"), `handler_name`, `subscriber_name`
APP_pubsub_handler_execution_time_seconds (APP_pubsub_handler_execution_time_seconds_count, APP_pubsub_handler_execution_time_bucket, APP_pubsub_handler_execution_time_seconds_sum)	A Prometheus Histogram. Records the execution time of the handler function wrapped by the middleware.	`handler_name`, `success` ("true" or "false")
APP_pubsub_publish_time_seconds (APP_pubsub_publish_time_seconds_count, APP_pubsub_publish_time_seconds_bucket, APP_pubsub_publish_time_seconds_sum)	A Prometheus Histogram. Registers the time of execution of the Publish function of the decorated publisher.	`handler_name`, `success` ("true" or "false"), `publisher_name`
HTTPAPP_http_request_duration_seconds (HTTPAPP_http_request_duration_seconds_count, HTTPAPP_http_request_duration_seconds_bucket, HTTPAPP_http_request_duration_sum)	A Prometheus histogram. Records the latency of the HTTP requests.	`code`, `handler`, `method`
HTTPAPP_http_requests_inflight	A Prometheus gauge. Records the number of inflight requests being handled at the same time.	`code`, `handler`, `method`
HTTPAPP_http_response_size_bytes (HTTPAPP_http_response_size_bytes_count, HTTPAPP_http_response_size_bytes_bucket, HTTPAPP_http_response_size_bytes_sum)	A Prometheus histogram. Records the size of the HTTP responses.	`handler`