This project implements transactional outbox pattern for eventual consistency between microservices. For relaying messages implements transaction log tailing pattern using Debezium and Change Data Capture(CDC).

Polling publisher is an alternative for relaying message but this is not the focus of the project.

How to Run

• For MS-SQL

  • up docker-compose docker-compose.mssql.yml
  • create migration then update database with dotnet ef cli
  • First Check CDC is enabled (You can also follow Microsoft documentation.)
    • Check CDC Enabled

      SELECT NAME, IS_CDC_ENABLED
      FROM SYS.DATABASES

    • If CDC is not enable then;

      USE DB -- for our example LEAVE or SHIFT
      GO
      EXEC SYS.SP_CDC_ENABLE_DB
      GO

    • Activate related outbox table for CDC

      EXEC SYS.SP_CDC_ENABLE_TABLE
      @source_schema = N'dbo',
      @source_name   = N'OUTBOX_EVENTS',
      @role_name     = NULL

    • If previous step returns you an error then execute below scripts then run previous scripts again;

      SELECT SRVNAME AS OLDNAME FROM MASTER.DBO.SYSSERVERS -- fc1a11b428b0
      
      SELECT SERVERPROPERTY('ServerName') AS NEWNAME --7bbf97d91d5b
      
      SP_DROPSERVER 'fc1a11b428b0';  
      GO  
      SP_ADDSERVER '7bbf97d91d5b', local;  
      GO

    • Check CDC is activated or not for table

      EXEC SYS.SP_CDC_HELP_CHANGE_DATA_CAPTURE

    • Somehow if you want to disable CDC on table;

      EXEC SYS.SP_CDC_DISABLE_TABLE
      @source_schema = N'dbo',  
      @source_name   = N'OUTBOX_EVENTS',  
      @capture_instance = N'LEAVE_OUTBOX_EVENTS'  

  • create debezium connector by using postman collection / create_connector-mssql
  • check connector is created / get_connectors
  • debezium and db settings is ok so ready to go. you can use swagger for creating new leave then get event then insert from shift.

• For PostgreSQL

  • up docker-compose docker-compose.postgres.yml
  • create migration then update database with dotnet ef cli
  • for postgres prefer debezium/postgres image because cdc configuration ok by default. configuration not necessary like ms-sql just setup debezium connector
  • create debezium connector by using postman collection / create_connector-postgresql
  • check connector is created / get_connectors
  • debezium and db settings is ok so ready to go. you can use swagger for creating new leave then get event then insert from shift.

inspired by this repo.