Chartjs-ChartJS distribute points evenly

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The problem in your addData function is that labels and data gets out of sync. While you keep data to a fixed length of 10 using Array.shift(), labels is steadily growing. This can be easily fixed if you also keep the labels to a fixed length of 10. 

let index = config.data.datasets[0].data.length;
function addData(a) {    
    config.data.labels.push('Data ' + ++index);
    config.data.datasets.forEach(dataset => dataset.data.push(a));    
    if (config.data.datasets[0].data.length > 10) {
        config.data.labels.shift();
        config.data.datasets[0].data.shift();
    }    
    myLineChart.update();
}

Please have a look at the following runnable code sample. Keep pressing the Add Value button too see what happens.

var ctx = document.getElementById('myChart').getContext('2d');
var config = {
    type: 'line',
    data: {
        labels: ['Data 1','Data 2','Data 3','Data 4','Data 5','Data 6','Data 7','Data 8','Data 9','Data 10'],
        datasets: [{
            label: 'CPU Allocation of all cores',
            data: [0,0,0,0,0,0,0,0,0,0],
            borderColor: [
                '#61559a',
                '#61559a',
                '#61559a',
                '#61559a',
                '#61559a',
                '#61559a',
                '#61559a',
                '#61559a',
                '#61559a',
                '#61559a'
            ],
            borderWidth: 1
        }]
    },
    options: {
        scaleOverride : true,
        scaleSteps : 10,
        scaleStepWidth : 10,
        scaleStartValue : 0,
        responsive: true,
        title: {
            display: false
        },
        tooltips: {
            mode: 'index',
            intersect: false,
        },
        hover: {
            mode: 'nearest',
            intersect: true
        },
        scales: {
            xAxes: [{
                display: false
            }],
            yAxes: [{
                ticks: {
                    suggestedMin: 0,
                    suggestedMax: 100,
                    stepSize: 10,
                    beginAtZero: true
                },
                display: true,
                scaleLabel: {
                    display: true,
                    labelString: 'Percent'
                }
            }]
        }
    }
}
var myLineChart = new Chart(ctx, config);
let index = config.data.datasets[0].data.length;
function addData(a) {    
    config.data.labels.push('Data ' + ++index);
    config.data.datasets.forEach(dataset => dataset.data.push(a));    
    if (config.data.datasets[0].data.length > 10) {
        config.data.labels.shift();
        config.data.datasets[0].data.shift();
    }    
    myLineChart.update();
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.min.js"></script>
<button onClick="addData(Math.floor(Math.random() * (100 + 1)))">Add Value</button>
<canvas id="myChart" height="80"></canvas>

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