distributed-system-visualizer/style.css at main · Deepak-2413/distributed-system-visualizer · GitHub

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const TOTAL_NODES = 3
const QUORUM = 2

let nodes = [
{active:true,data:{}},
{active:true,data:{}},
{active:true,data:{}}
]

function log(msg){
let logDiv=document.getElementById("logBody")
let time=new Date().toLocaleTimeString()
logDiv.innerHTML=`[${time}] ${msg}<br>`+logDiv.innerHTML
}

function updateUI(){

nodes.forEach((node,i)=>{

let nodeDiv=document.getElementById("node"+i)
let status=nodeDiv.querySelector(".status")
let dataDiv=nodeDiv.querySelector(".data")

status.textContent=node.active?"Status: Active":"Status: FAILED"

nodeDiv.classList.toggle("failed",!node.active)

dataDiv.innerHTML=""

for(let k in node.data){
dataDiv.innerHTML+=`<p>${k} : ${node.data[k].value} (v${node.data[k].version})</p>`
}

})

updateHealth()

}

function updateHealth(){

let active=nodes.filter(n=>n.active).length
let failed=TOTAL_NODES-active

let keys=new Set()

nodes.forEach(n=>{
if(n.active){
Object.keys(n.data).forEach(k=>keys.add(k))
}
})

document.getElementById("activeCount").textContent=active
document.getElementById("failedCount").textContent=failed
document.getElementById("quorumCount").textContent=QUORUM
document.getElementById("keyCount").textContent=keys.size

}

function putData(){

let key=document.getElementById("keyInput").value
let value=document.getElementById("valueInput").value

if(!key||!value) return

let alive=nodes.filter(n=>n.active)

if(alive.length<QUORUM){
log("PUT failed: quorum not met")
return
}

let version=1

alive.forEach(n=>{
if(n.data[key]) version=Math.max(version,n.data[key].version+1)
})

alive.forEach(n=>{
n.data[key]={value,version}
})

log(`PUT committed with quorum (${alive.length}/${TOTAL_NODES})`)
updateUI()

}

function getData(){

let key=document.getElementById("keyInput").value
if(!key) return

let responses=[]

nodes.forEach(n=>{
if(n.active&&n.data[key]) responses.push(n.data[key])
})

if(responses.length<QUORUM){
log("GET failed: quorum not satisfied")
return
}

let latest=responses.reduce((a,b)=>b.version>a.version?b:a)

log(`GET success → value="${latest.value}"`)
}

function failNode(id){

nodes[id].active=false
log(`Node ${id} FAILED`)
updateUI()

}

function recoverNode(id){

nodes[id].active=true
log(`Node ${id} RECOVERED`)

let recovered=nodes[id]

nodes.forEach(n=>{

if(n.active&&n!==recovered){

for(let k in n.data){

if(!recovered.data[k]||n.data[k].version>recovered.data[k].version){
recovered.data[k]={...n.data[k]}
}

}

}

})

log(`Node ${id} rebalanced with latest data`)
updateUI()

}

function resetCluster(){

nodes=[
{active:true,data:{}},
{active:true,data:{}},
{active:true,data:{}}
]

log("Cluster reset")
updateUI()

}

updateUI()