User Service
User Service is an application for handling and processing Events via socket connections.
Supported events are
- Follow
- Unfollow
- Broadcast
- Private Message
- Status Update
Implementation details
On app start two sockets are initialized one for clients another for events.
The events arrive out of order but app should deliver them by order. EventsBuffer class is taking care of this by using BlockingQueue with a comparator. Capacity of the queue is configurable and is exported to JMX so can be changed during runtime to fit our needs.
Key Classes
- SocketServer basically all functionality related to opening and reading sockets
- EventsBuffer dealing with events order and pushing them to event processors
- ClientStore holding all connected clients and removes them when connection is closed
- FollowerStore holding data about which followers (who follows whom)
Technology stack
- Java 8
- Spring
- Javaslang
- Lombock
- Guava
- Junit, Mockito, Assertj
Build and Run
To build and run jar file
./gradlew build
java -jar build/libs/user-service-0.1-SNAPSHOT.jar
To build and run Docker
./gradlew buildDocker
docker run -p 9090:9090 -p 9099:9099 soundcloud/user-service:1.0-SNAPSHOT
NOTE: You should have Lombock plugin installed to build and run the app with IDE
Known issues
While running with docker follower-maze-2.0.jar is failing while waiting for remaining notifications with
ಠ_ಠ SOMETHING WENT WRONG ಠ_ಠ
Configuration
- buffer.capacity - default
1000. Represents capacity of the buffer. When size of buffer gets to the limit half of the buffer is being flushed (events are being send) - buffer.scheduleFixedRate - default
2000(2sec). Used for flushing events buffer if there are no incoming events. - socket.address - default localhost. Socket address
- socket.eventPort - default
9090. Socket address - socket.clientPort - default
9099. Socket address
The app uses application.yml in classpath by default
If you need custom configuration use
-Dspring.config.location=/path
For changing log lvl you can use
-Dlogging.level.org.springframework=DEBUG
Finally
Hope you have enjoyed reviewing my code as much as I writing it :)