replication-log

task description:

The Replicated Log should have the following deployment architecture: one Master and any number of Secondaries.

Replication log service where there are two parts: master and secondary.

Master should expose simple HTTP server with:

• POST method - appends a message into the in-memory list
• GET method - returns all messages from the in-memory list

Secondary should expose simple HTTP server with:

GET method - returns all replicated messages from the in-memory list

Properties and assumptions:

• after each POST request, the message should be replicated on Secondary servers
• Master should ensure that Secondaries have received a message via ACK
• POST request should be finished only after receiving ACKs from all Secondaries (blocking replication approach)
• to test that the replication is blocking, introduce the delay/sleep on the Secondary
• on this stage assume that communication channel is a perfect link (no failures and messages lost)
• any RPC frameworks can be used for Master-Secondary communication (Sockets, language-specific RPC, HTTP, Rest, gRPC, …)
• Master and Secondaries should run in Docker

How to run:

How to run docker-compose:

• docker-compose up --build
• for communicate between containers, you should use such url: http://<docker_compose_service_name>:<service_internal_port>/

For run master/secondary dockerfile:

Master:

• build: docker build -t master -f master.Dockerfile .
• run: docker run -p 5100:8000 master

Secondary:

• build: docker build -t secondary -f secondary.Dockerfile .
• run: docker run -p 5200:8000 secondary