The bimodal-multicast from rstefan1

Connection refused at solicitation post

In tests:

HTTP Server
/home/runner/workspace/src/github.com/rstefan1/bimodal-multicast/pkg/internal/server/server_test.go:57
  at solicitation request
  /home/runner/workspace/src/github.com/rstefan1/bimodal-multicast/pkg/internal/server/server_test.go:186
    responds with synchronization message [It]
    /home/runner/workspace/src/github.com/rstefan1/bimodal-multicast/pkg/internal/server/server_test.go:217

    Expected success, but got an error:
        <*url.Error | 0xc0000b5e90>: {
            Op: "Post",
            URL: "http://localhost:35619/solicitation",
            Err: {
                Op: "dial",
                Net: "tcp",
                Source: nil,
                Addr: {
                    IP: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 255, 127, 0, 0, 1],
                    Port: 35619,
                    Zone: "",
                },
                Err: {Syscall: "connect", Err: 0x6f},
            },
        }
        Post http://localhost:35619/solicitation: dial tcp 127.0.0.1:35619: connect: connection refused

    /home/runner/workspace/src/github.com/rstefan1/bimodal-multicast/pkg/internal/server/server_test.go:244

    Full Stack Trace
    	/home/runner/workspace/src/github.com/rstefan1/bimodal-multicast/vendor/github.com/onsi/gomega/internal/assertion/assertion.go:75 +0x305
    github.com/rstefan1/bimodal-multicast/vendor/github.com/onsi/gomega/internal/assertion.(*Assertion).To(0xc0000c5700, 0xae0240, 0xef3228, 0x0, 0x0, 0x0, 0x0)
    	/home/runner/workspace/src/github.com/rstefan1/bimodal-multicast/vendor/github.com/onsi/gomega/internal/assertion/assertion.go:38 +0x11f
    github.com/rstefan1/bimodal-multicast/pkg/internal/server.glob..func1.4.3()
    	/home/runner/workspace/src/github.com/rstefan1/bimodal-multicast/pkg/internal/server/server_test.go:244 +0x921
    github.com/rstefan1/bimodal-multicast/vendor/github.com/onsi/ginkgo/internal/leafnodes.(*runner).runSync(0xc0000c3020, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, ...)
    	/home/runner/workspace/src/github.com/rstefan1/bimodal-multicast/pkg/internal/server/server_suite_test.go:28 +0xf7
    testing.tRunner(0xc00018a200, 0xa68ac8)
    	/usr/local/golang/1.11/go/src/testing/testing.go:827 +0x163
    created by testing.(*T).Run
    	/usr/local/golang/1.11/go/src/testing/testing.go:878 +0x651
    ```

Let user to register callbacks for each message from buffer

Discard messages for which `gossipCount` exceeds the garbage-collection limit, `G` parameter

if roundNumber - msgBuffer[slot].gossipCount > G {
    discard(msgBuffer[slot])
}

Use RWMutex instead of Mutex

It may be more efficient.

Validate performance, scalability and data consistency

Update peers list at runtime

Gossip Round

implement GossipRound goroutine
Protocol/GossipRound must be an object with the method Start and peers and buffers private fields
allow the client to inject some configs (HTTP server address & port, an initial state of buffers, size of buffers, etc)
add a channel to gracefully shut down HTTP Server & test it
add a channel to gracefully shut down Gossip Round Goroutine & test it
tests

Metrics in readme

Implement circular buffers

Round Retransmission Limit (optimization)

Optimization: Limit the maximum amount of data (bytes) that a process/node will retransmit in a round.

For more information, check: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwjr5IX4vMPhAhUOlosKHSG6Cg0QFjAAegQIABAC&url=http%3A%2F%2Fwww.csl.mtu.edu%2Fcs6461%2Fwww%2FReading%2FBirman99.pdf&usg=AOvVaw2fZsGjb7hFGcQu1d4_pBSh

Messages from buffer must be in a command-args form

type Message struct{
    Command: string,
    Args: []string,
}

Add tests where a message already exists in the buffer

Add test for the following case: receive synchronization message with a message that already exists in the buffer message

unit test in http server suite
unit test in buffer suite

Fix make dependencies and ginkgo vendor

Multicast for some retransmissions (optimization)

For more information, check: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwjr5IX4vMPhAhUOlosKHSG6Cg0QFjAAegQIABAC&url=http%3A%2F%2Fwww.csl.mtu.edu%2Fcs6461%2Fwww%2FReading%2FBirman99.pdf&usg=AOvVaw2fZsGjb7hFGcQu1d4_pBSh

Error when message buffer is empty

bimodal-multicast/pkg/internal/gossip/gossip.go

Line 80 in 3723796

if g.peerBuffer.Length() == 0 {

if g.peerBuffer.Length() == 0 || g.msgBuffer.Length() == 0{ 
     gossipLen = 0
} else {
     // ...
}

Fix linting

Uses pointers in the functions with the buffers

Add integration tests

Rename httpserver to server and gossipserver to gossiper

Implement publisher-subcriber pattern

Nodes should subscribe to certain events. Each message has an event type. When a node receives a message of the type of event it subscribes to, it will call the associated callback.

Update readme with more detail about the protocol/algorithm

Connection refused when restart the protocol

Describe the bug
When I restart the protocol, I get the following error:

Gossiper from localhost:34241 can not marshal the gossip message: Post http://localhost:38133/gossip: dial tcp [::1]:38133: connect: connection refused

The protocol from [::1]:38133 was restarted.

How To Reproduce

p.Stop()
p.Start()

Most-Recent-First Retransmission (optimization)

For more information, check: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwjr5IX4vMPhAhUOlosKHSG6Cg0QFjAAegQIABAC&url=http%3A%2F%2Fwww.csl.mtu.edu%2Fcs6461%2Fwww%2FReading%2FBirman99.pdf&usg=AOvVaw2fZsGjb7hFGcQu1d4_pBSh

Messages must have interface type

Run Callback when add new message in bufferr in bmmc.AddMessage() func

Add given peer in peersBuffer in bmmc.AddPeer() func

bimodal-multicast/pkg/bmmc/bmmc.go

Line 142 in 3723796

b.msgBuffer.AddMessage(

p.peerBuffer.AddPeer(
    peer.NewPeer(addr, port),
)

b.msgBuffer.AddMessage(...)

Messages must have and a timestamp and an ID

Use k8s logger

Add a package for sending HTTP messages

Multiple calls for the same message

Two request messages may appear at the same time. The callbacks will be called twice, once for each message, but the message will be added once in the buffer.

GossipRoundNumber should not be shared between goroutines

Gossip address and HTTP address must be same

HTTP error

2019/05/01 21:27:53 http: Accept error: accept tcp 127.0.0.1:44821: accept4: too many open files; retrying in 5ms

Check: https://medium.com/@nate510/don-t-use-go-s-default-http-client-4804cb19f779

In synchronization request, update buffer only if round numbers are same

Add example of use the library

Add validation for callback types

Remove given peer from peersBuffer in bmmc.RemovePeer() func

HTTP Server

handler for Gossip Message
handler for Solicitation Message
handler for Synchronization Message
put in gossip message the round number
unit tests for handlers
catch the errors
cleanup code (set random ports for servers, remove sleeps from tests, use Eventually in tests, etc.)