# Goshimmer study note

## System envronment
- Hardware
- IBM System x3550 M4 Server -[7914IA4]-
- Software
- No LSB modules are available.
- Distributor ID: Ubuntu
- Description: Ubuntu 18.04.2 LTS
- Release: 18.04
- Codename: bionic

## Preparation
- Go 1.12

## Git Repository
- https://github.com/iotaledger/goshimmer

## Installation
- Clone goshimmer repository
- ```git clone https://github.com/iotaledger/goshimmer```
- ``` cd goshimmer/```
- Build your executable
- ```go build -o shimmer```
- Run
- ```./shimmer -node-disable-plugins statusscreen -node-enable-plugins "dashboard"```

#### Ports:

tcp        0      0 0.0.0.0:14626           0.0.0.0:*               LISTEN      6093/shimmer        
tcp        0      0 0.0.0.0:14666           0.0.0.0:*               LISTEN      6093/shimmer        
tcp6       0      0 :::8080                 :::*                    LISTEN      6093/shimmer        
tcp6       0      0 :::8081                 :::*                    LISTEN      6093/shimmer    

#### Output:

#### Dashboard
- http://node0.puyuma.org:8081/dashboard

## Systemd

[Unit]
Description=Goshimmer FullNode
After=network-online.target

[Service]
WorkingDirectory=/{hide}/goshimmer
EnvironmentFile=-/{hide}
ExecStart=/{hide}/shimmer -node-disable-plugins statusscreen
KillMode=process
Type=simple
User={hide}
Group={hide}
StandardOutput=syslog
StandardError=syslog
SyslogIdentifier={hide}

[Install]
WantedBy=multi-user.target

## SPAM
- http://node0.puyuma.org:8080/spammer?cmd=start&tps=10000


## Architecture

[main.go](https://github.com/iotaledger/goshimmer/blob/master/main.go#L24)

func main() {
	node.Run(
		cli.PLUGIN,
		autopeering.PLUGIN,
		gossip.PLUGIN,
		gossip_on_solidification.PLUGIN,
		tangle.PLUGIN,
		bundleprocessor.PLUGIN,
		analysis.PLUGIN,
		gracefulshutdown.PLUGIN,
		tipselection.PLUGIN,
		zeromq.PLUGIN,
		dashboard.PLUGIN,
		metrics.PLUGIN,

		statusscreen.PLUGIN,
		statusscreen_tps.PLUGIN,

		webapi.PLUGIN,
		webapi_gtta.PLUGIN,
		webapi_spammer.PLUGIN,
	)
}

在 [node] package , 有兩處要注意
1. [node.go](https://github.com/iotaledger/goshimmer/blob/master/packages/node/node.go#L40)

func Run(plugins ...*Plugin) *Node {
	node := New(plugins...)
	node.Run()

	return node
}

執行順序是 Run -> New -> configure -> 每個插件的 run 函數

configure會初始化全部插件的初始化

另外無法理解 node.Run() , node的結構似乎沒有run函數

2. [plugin.go](https://github.com/iotaledger/goshimmer/blob/master/packages/node/plugin.go#L26)

// Creates a new plugin with the given name, default status and callbacks.
// The last specified callback is the mandatory run callback, while all other callbacks are configure callbacks.
func NewPlugin(name string, status int, callback Callback, callbacks ...Callback) *Plugin {
	plugin := &Plugin{
		Name:   name,
		Status: status,
		Events: pluginEvents{
			Configure: events.NewEvent(pluginCaller),
			Run:       events.NewEvent(pluginCaller),
		},
	}

	// make the plugin known to the parameters
	parameter.AddPlugin(name, status)

	if len(callbacks) >= 1 {
		plugin.Events.Configure.Attach(events.NewClosure(callback))
		for _, callback = range callbacks[:len(callbacks)-1] {
			plugin.Events.Configure.Attach(events.NewClosure(callback))
		}

		plugin.Events.Run.Attach(events.NewClosure(callbacks[len(callbacks)-1]))
	} else {
		plugin.Events.Run.Attach(events.NewClosure(callback))
	}

	return plugin
}

每個packages或plugin , 都會有plugin.go

裡面都有 configure 與 run 函數 , configure用來初始化packages或plugin ; run用來註冊event對應的callback函數 , 或對 daemon 的backgroundWorker 註冊 callback函數

並透過NewPlugin在main.go去執行configure與run , configure先 , run後(Main.go 的 PLUGIN是個變數 , 在 plugin.go 中由NewPlugin賦值)

從以上可以得知 , 要trace某個package和plugin , 先去看對應目錄下的plugin.go

## Autopeering

#### Work Flow:

- [configure](https://github.com/iotaledger/goshimmer/blob/588e0fffc8b9d8dec08bb74cc0b792afbc43c228/plugins/autopeering/plugin.go#L21)

func configure(plugin *node.Plugin) {
	saltmanager.Configure(plugin)
	instances.Configure(plugin)
	server.Configure(plugin)
	protocol.Configure(plugin)
	peerstorage.Configure(plugin)

	daemon.Events.Shutdown.Attach(events.NewClosure(func() {
		server.Shutdown(plugin)
	}))

	configureLogging(plugin)
}

- [run](https://github.com/iotaledger/goshimmer/blob/588e0fffc8b9d8dec08bb74cc0b792afbc43c228/plugins/autopeering/plugin.go#L35)

func run(plugin *node.Plugin) {
	instances.Run(plugin)
	server.Run(plugin)
	protocol.Run(plugin)
}

#### Neighbors:

According the chapter `4.2 Choosing neighbors` of [coordecide whitepaper](https://files.iota.org/papers/Coordicide_WP.pdf), neighbor can be divided into *Chosen neighbors* and *Accepted Neighbors* the definition as below:

- Chosen neighbors. The neighbors that the node proactively choose from
his list.
- Accepted Neighbors. The neighbors that choose the node as their peer.

- Accept neighbors:
- [knownPeers](https://github.com/iotaledger/goshimmer/blob/master/plugins/autopeering/instances/knownpeers/instance.go)
- Get from [EntryNode](https://github.com/iotaledger/goshimmer/blob/d1195f0a93a79d8d63a36a1c79eef3ebbba18d44/plugins/autopeering/parameters/parameters.go#L7)
- Get from [peerstorage](https://github.com/iotaledger/goshimmer/blob/d1195f0a93a79d8d63a36a1c79eef3ebbba18d44/plugins/autopeering/peerstorage/peerstorage.go#L49)
- Get from [incoming_ping](https://github.com/iotaledger/goshimmer/blob/d1195f0a93a79d8d63a36a1c79eef3ebbba18d44/plugins/autopeering/protocol/incoming_ping_processor.go)

- Chosen neighbors:
- [chosenPeer](https://github.com/iotaledger/goshimmer/blob/d1195f0a93a79d8d63a36a1c79eef3ebbba18d44/plugins/autopeering/protocol/outgoing_ping_processor.go#L69)
- [neighborhood.LIST_INSTANCE](https://github.com/iotaledger/goshimmer/blob/d1195f0a93a79d8d63a36a1c79eef3ebbba18d44/plugins/autopeering/protocol/outgoing_ping_processor.go#L66)
- [neighborhood.LIST_INSTANCE update from knownPeers](https://github.com/iotaledger/goshimmer/blob/d1195f0a93a79d8d63a36a1c79eef3ebbba18d44/plugins/autopeering/instances/neighborhood/instance.go#L43)

## Autopeering structure

#### Issues:
- Gossip duration
- jkrvivian 3:56 PM: 不然我 spam 一下，看你會不會收到
- jkrvivian 3:58 PM: 開始！
- 
- Maybe some problem in the [distance](https://files.iota.org/papers/Coordicide_WP.pdf) calculate
- I should add vivian as `EntryNode`

- Private Tangle
- Deploy A, B node
- Remove IF `EntryNode` from A, B
- A, B add neighbors to each other
- SPAM from A
- A, B sould be a private network and DB storage

## Tools
- Peer visualize
- http://storage.googleapis.com/goshimmer-visualizer/index.html
- Graph of a Go program using dot format
- [go-callvis](https://github.com/TrueFurby/go-callvis)
- [Demo](http://node0.puyuma.org:7878)

## Reference
- [Coordicide whitepaper](https://files.iota.org/papers/Coordicide_WP.pdf)
- [Coordicide whitepaper (simple chinese language)](https://shimo.im/docs/F2QiPRN18eIyiY7M)