victorskl / strike

Strike - Distributed Multi-Server Chat System

Strike

Strike is a Distributed Multi-Server Chat System. The architecture of the system is presented in the following diagram.

Demo

strike's Issues

Fix bug: Client send message

Client send message should always go through server. Then server will distribute the chat message to all clients.

Create tag to cut off before staring DA

Done.
https://github.com/victorskl/strike/releases/tag/v1.0.0-alpha

Implement Failure Detection - Gossip base

Implement Reliable Failure Detection

Implement Reliable Multicast over IP Multicast

The is implemented at xmcast project. This is just to observe how multicast group communication could be a solution for chat system communication sub-system layer, i.e. to argument Strike use of TCP as communication layer.

Refactor Client UI Code

• Rewrite and replace school client code
• Fix bugs

Implement Load Balancer

Implement Client to use Load Balancer

If Load Balancer Mode is available, allow client go through this.

Implement Consensus

• to get consensus to kick the dead server

Unhandle Session Timeout

Shiro has user session timeout. This needs to be handled.

Exception in thread "pool-3-thread-2" org.apache.shiro.session.UnknownSessionException: There is no session with id [d6bab863-6950-43c5-aaad-d514681022c8]
	at org.apache.shiro.session.mgt.eis.AbstractSessionDAO.readSession(AbstractSessionDAO.java:170)
	at org.apache.shiro.session.mgt.DefaultSessionManager.retrieveSessionFromDataSource(DefaultSessionManager.java:236)
	at org.apache.shiro.session.mgt.DefaultSessionManager.retrieveSession(DefaultSessionManager.java:222)
	at org.apache.shiro.session.mgt.AbstractValidatingSessionManager.doGetSession(AbstractValidatingSessionManager.java:118)
	at org.apache.shiro.session.mgt.AbstractNativeSessionManager.lookupSession(AbstractNativeSessionManager.java:148)
	at org.apache.shiro.session.mgt.AbstractNativeSessionManager.lookupRequiredSession(AbstractNativeSessionManager.java:152)
	at org.apache.shiro.session.mgt.AbstractNativeSessionManager.getAttribute(AbstractNativeSessionManager.java:249)
	at org.apache.shiro.session.mgt.DelegatingSession.getAttribute(DelegatingSession.java:141)
	at org.apache.shiro.session.ProxiedSession.getAttribute(ProxiedSession.java:121)
	at org.apache.shiro.session.ProxiedSession.getAttribute(ProxiedSession.java:121)
	at org.apache.shiro.session.ProxiedSession.getAttribute(ProxiedSession.java:121)
	at org.apache.shiro.subject.support.DelegatingSubject.getRunAsPrincipalsStack(DelegatingSubject.java:469)
	at org.apache.shiro.subject.support.DelegatingSubject.getPrincipals(DelegatingSubject.java:153)
	at org.apache.shiro.subject.support.DelegatingSubject.getPrincipal(DelegatingSubject.java:149)
	at strike.service.ClientConnection.performUserLogoutAndUserSessionCleanUp(ClientConnection.java:122)
	at strike.service.ClientConnection.run(ClientConnection.java:104)
	at org.apache.shiro.subject.support.SubjectRunnable.doRun(SubjectRunnable.java:120)
	at org.apache.shiro.subject.support.SubjectRunnable.run(SubjectRunnable.java:108)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)

Implement Server Timestamping Message

Timestamp the message at server side using Instant in UTC.

http://docs.oracle.com/javase/8/docs/api/java/time/Instant.html

Implement Fast Bully Algorithm