path: root/cmd/geth/monitorcmd.go

package main

import (
    "fmt"
    "math"
    "reflect"
    "runtime"
    "sort"
    "strings"
    "time"

    "github.com/codegangsta/cli"
    "github.com/ethereum/go-ethereum/cmd/utils"
    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/rpc"
    "github.com/ethereum/go-ethereum/rpc/codec"
    "github.com/ethereum/go-ethereum/rpc/comms"
    "github.com/gizak/termui"
)

var (
    monitorCommandAttachFlag = cli.StringFlag{
        Name:  "attach",
        Value: "ipc:" + common.DefaultIpcPath(),
        Usage: "API endpoint to attach to",
    }
    monitorCommandRowsFlag = cli.IntFlag{
        Name:  "rows",
        Value: 5,
        Usage: "Maximum rows in the chart grid",
    }
    monitorCommandRefreshFlag = cli.IntFlag{
        Name:  "refresh",
        Value: 3,
        Usage: "Refresh interval in seconds",
    }
    monitorCommand = cli.Command{
        Action: monitor,
        Name:   "monitor",
        Usage:  `Geth Monitor: node metrics monitoring and visualization`,
        Description: `
The Geth monitor is a tool to collect and visualize various internal metrics
gathered by the node, supporting different chart types as well as the capacity
to display multiple metrics simultaneously.
`,
        Flags: []cli.Flag{
            monitorCommandAttachFlag,
            monitorCommandRowsFlag,
            monitorCommandRefreshFlag,
        },
    }
)

// monitor starts a terminal UI based monitoring tool for the requested metrics.
func monitor(ctx *cli.Context) {
    var (
        client comms.EthereumClient
        err    error
    )
    // Attach to an Ethereum node over IPC or RPC
    endpoint := ctx.String(monitorCommandAttachFlag.Name)
    if client, err = comms.ClientFromEndpoint(endpoint, codec.JSON); err != nil {
        utils.Fatalf("Unable to attach to geth node: %v", err)
    }
    defer client.Close()

    xeth := rpc.NewXeth(client)

    // Retrieve all the available metrics and resolve the user pattens
    metrics, err := retrieveMetrics(xeth)
    if err != nil {
        utils.Fatalf("Failed to retrieve system metrics: %v", err)
    }
    monitored := resolveMetrics(metrics, ctx.Args())
    if len(monitored) == 0 {
        list := expandMetrics(metrics, "")
        sort.Strings(list)
        utils.Fatalf("No metrics specified.\n\nAvailable:\n - %s", strings.Join(list, "\n - "))
    }
    sort.Strings(monitored)
    if cols := len(monitored) / ctx.Int(monitorCommandRowsFlag.Name); cols > 6 {
        utils.Fatalf("Requested metrics (%d) spans more that 6 columns:\n - %s", len(monitored), strings.Join(monitored, "\n - "))
    }
    // Create and configure the chart UI defaults
    if err := termui.Init(); err != nil {
        utils.Fatalf("Unable to initialize terminal UI: %v", err)
    }
    defer termui.Close()

    termui.UseTheme("helloworld")

    rows := len(monitored)
    if max := ctx.Int(monitorCommandRowsFlag.Name); rows > max {
        rows = max
    }
    cols := (len(monitored) + rows - 1) / rows
    for i := 0; i < rows; i++ {
        termui.Body.AddRows(termui.NewRow())
    }
    // Create each individual data chart
    footer := termui.NewPar("")
    footer.HasBorder = true
    footer.Height = 3

    charts := make([]*termui.LineChart, len(monitored))
    data := make([][]float64, len(monitored))
    for i := 0; i < len(data); i++ {
        data[i] = make([]float64, 512)
    }
    for i, metric := range monitored {
        charts[i] = termui.NewLineChart()
        if runtime.GOOS == "windows" {
            charts[i].Mode = "dot"
        }
        charts[i].Data = make([]float64, 512)
        charts[i].DataLabels = []string{""}
        charts[i].Height = (termui.TermHeight() - footer.Height) / rows
        charts[i].AxesColor = termui.ColorWhite
        charts[i].PaddingBottom = -2

        charts[i].Border.Label = metric
        charts[i].Border.LabelFgColor = charts[i].Border.FgColor | termui.AttrBold
        charts[i].Border.FgColor = charts[i].Border.BgColor

        row := termui.Body.Rows[i%rows]
        row.Cols = append(row.Cols, termui.NewCol(12/cols, 0, charts[i]))
    }
    termui.Body.AddRows(termui.NewRow(termui.NewCol(12, 0, footer)))
    termui.Body.Align()
    termui.Render(termui.Body)

    refreshCharts(xeth, monitored, data, charts, ctx, footer)
    termui.Render(termui.Body)

    // Watch for various system events, and periodically refresh the charts
    refresh := time.Tick(time.Duration(ctx.Int(monitorCommandRefreshFlag.Name)) * time.Second)
    for {
        select {
        case event := <-termui.EventCh():
            if event.Type == termui.EventKey && event.Key == termui.KeyCtrlC {
                return
            }
            if event.Type == termui.EventResize {
                termui.Body.Width = termui.TermWidth()
                for _, chart := range charts {
                    chart.Height = (termui.TermHeight() - footer.Height) / rows
                }
                termui.Body.Align()
                termui.Render(termui.Body)
            }
        case <-refresh:
            refreshCharts(xeth, monitored, data, charts, ctx, footer)
            termui.Render(termui.Body)
        }
    }
}

// retrieveMetrics contacts the attached geth node and retrieves the entire set
// of collected system metrics.
func retrieveMetrics(xeth *rpc.Xeth) (map[string]interface{}, error) {
    return xeth.Call("debug_metrics", []interface{}{true})
}

// resolveMetrics takes a list of input metric patterns, and resolves each to one
// or more canonical metric names.
func resolveMetrics(metrics map[string]interface{}, patterns []string) []string {
    res := []string{}
    for _, pattern := range patterns {
        res = append(res, resolveMetric(metrics, pattern, "")...)
    }
    return res
}

// resolveMetrics takes a single of input metric pattern, and resolves it to one
// or more canonical metric names.
func resolveMetric(metrics map[string]interface{}, pattern string, path string) []string {
    results := []string{}

    // If a nested metric was requested, recurse optionally branching (via comma)
    parts := strings.SplitN(pattern, "/", 2)
    if len(parts) > 1 {
        for _, variation := range strings.Split(parts[0], ",") {
            if submetrics, ok := metrics[variation].(map[string]interface{}); !ok {
                utils.Fatalf("Failed to retrieve system metrics: %s", path+variation)
                return nil
            } else {
                results = append(results, resolveMetric(submetrics, parts[1], path+variation+"/")...)
            }
        }
        return results
    }
    // Depending what the last link is, return or expand
    for _, variation := range strings.Split(pattern, ",") {
        switch metric := metrics[variation].(type) {
        case float64:
            // Final metric value found, return as singleton
            results = append(results, path+variation)

        case map[string]interface{}:
            results = append(results, expandMetrics(metric, path+variation+"/")...)

        default:
            utils.Fatalf("Metric pattern resolved to unexpected type: %v", reflect.TypeOf(metric))
            return nil
        }
    }
    return results
}

// expandMetrics expands the entire tree of metrics into a flat list of paths.
func expandMetrics(metrics map[string]interface{}, path string) []string {
    // Iterate over all fields and expand individually
    list := []string{}
    for name, metric := range metrics {
        switch metric := metric.(type) {
        case float64:
            // Final metric value found, append to list
            list = append(list, path+name)

        case map[string]interface{}:
            // Tree of metrics found, expand recursively
            list = append(list, expandMetrics(metric, path+name+"/")...)

        default:
            utils.Fatalf("Metric pattern %s resolved to unexpected type: %v", path+name, reflect.TypeOf(metric))
            return nil
        }
    }
    return list
}

// fetchMetric iterates over the metrics map and retrieves a specific one.
func fetchMetric(metrics map[string]interface{}, metric string) float64 {
    parts, found := strings.Split(metric, "/"), true
    for _, part := range parts[:len(parts)-1] {
        metrics, found = metrics[part].(map[string]interface{})
        if !found {
            return 0
        }
    }
    if v, ok := metrics[parts[len(parts)-1]].(float64); ok {
        return v
    }
    return 0
}

// refreshCharts retrieves a next batch of metrics, and inserts all the new
// values into the active datasets and charts
func refreshCharts(xeth *rpc.Xeth, metrics []string, data [][]float64, charts []*termui.LineChart, ctx *cli.Context, footer *termui.Par) {
    values, err := retrieveMetrics(xeth)
    for i, metric := range metrics {
        data[i] = append([]float64{fetchMetric(values, metric)}, data[i][:len(data[i])-1]...)
        updateChart(metric, data[i], charts[i], err)
    }
    updateFooter(ctx, err, footer)
}

// updateChart inserts a dataset into a line chart, scaling appropriately as to
// not display weird labels, also updating the chart label accordingly.
func updateChart(metric string, data []float64, chart *termui.LineChart, err error) {
    dataUnits := []string{"", "K", "M", "G", "T", "E"}
    timeUnits := []string{"ns", "µs", "ms", "s", "ks", "ms"}
    colors := []termui.Attribute{termui.ColorBlue, termui.ColorCyan, termui.ColorGreen, termui.ColorYellow, termui.ColorRed, termui.ColorRed}

    // Extract only part of the data that's actually visible
    data = data[:chart.Width*2]

    // Find the maximum value and scale under 1K
    high := data[0]
    for _, value := range data[1:] {
        high = math.Max(high, value)
    }
    unit, scale := 0, 1.0
    for high >= 1000 {
        high, unit, scale = high/1000, unit+1, scale*1000
    }
    // Update the chart's data points with the scaled values
    for i, value := range data {
        chart.Data[i] = value / scale
    }
    // Update the chart's label with the scale units
    chart.Border.Label = metric

    units := dataUnits
    if strings.Contains(metric, "/Percentiles/") || strings.Contains(metric, "/pauses/") {
        units = timeUnits
    }
    if len(units[unit]) > 0 {
        chart.Border.Label += " [" + units[unit] + "]"
    }
    chart.LineColor = colors[unit] | termui.AttrBold
    if err != nil {
        chart.LineColor = termui.ColorRed | termui.AttrBold
    }
}

// updateFooter updates the footer contents based on any encountered errors.
func updateFooter(ctx *cli.Context, err error, footer *termui.Par) {
    // Generate the basic footer
    refresh := time.Duration(ctx.Int(monitorCommandRefreshFlag.Name)) * time.Second
    footer.Text = fmt.Sprintf("Press Ctrl+C to quit. Refresh interval: %v.", refresh)
    footer.TextFgColor = termui.Theme().ParTextFg | termui.AttrBold

    // Append any encountered errors
    if err != nil {
        footer.Text = fmt.Sprintf("Error: %v.", err)
        footer.TextFgColor = termui.ColorRed | termui.AttrBold
    }
}