path: root/cmd/geth/monitorcmd.go

package main

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

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

// monitor starts a terminal UI based monitoring tool for the requested metrics.
func monitor(ctx *cli.Context) {
    var (
        client comms.EthereumClient
        args   []string
        err    error
    )
    // Attach to an Ethereum node over IPC or RPC
    if ctx.Args().Present() {
        // Try to interpret the first parameter as an endpoint
        client, err = comms.ClientFromEndpoint(ctx.Args().First(), codec.JSON)
        if err == nil {
            args = ctx.Args().Tail()
        }
    }
    if !ctx.Args().Present() || err != nil {
        // Either no args were given, or not endpoint, use defaults
        cfg := comms.IpcConfig{
            Endpoint: ctx.GlobalString(utils.IPCPathFlag.Name),
        }
        args = ctx.Args()
        client, err = comms.NewIpcClient(cfg, codec.JSON)
    }
    if 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 := xeth.Call("debug_metrics", []interface{}{true})
    if err != nil {
        utils.Fatalf("Failed to retrieve system metrics: %v", err)
    }
    monitored := resolveMetrics(metrics, args)
    sort.Strings(monitored)

    // Create the access function and check that the metric exists
    value := func(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 {
                utils.Fatalf("Metric not found: %s", metric)
            }
        }
        if v, ok := metrics[parts[len(parts)-1]].(float64); ok {
            return v
        }
        utils.Fatalf("Metric not float64: %s", metric)
        return 0
    }
    // 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 := 5
    cols := (len(monitored) + rows - 1) / rows
    for i := 0; i < rows; i++ {
        termui.Body.AddRows(termui.NewRow())
    }
    // Create each individual data chart
    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()

        charts[i].Data = make([]float64, 512)
        charts[i].DataLabels = []string{""}
        charts[i].Height = termui.TermHeight() / rows
        charts[i].AxesColor = termui.ColorWhite
        charts[i].LineColor = termui.ColorGreen
        charts[i].PaddingBottom = -1

        charts[i].Border.Label = metric
        charts[i].Border.LabelFgColor = charts[i].Border.FgColor
        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.Align()
    termui.Render(termui.Body)

    refresh := time.Tick(time.Second)
    for {
        select {
        case event := <-termui.EventCh():
            if event.Type == termui.EventKey && event.Ch == 'q' {
                return
            }
            if event.Type == termui.EventResize {
                termui.Body.Width = termui.TermWidth()
                for _, chart := range charts {
                    chart.Height = termui.TermHeight() / rows
                }
                termui.Body.Align()
                termui.Render(termui.Body)
            }
        case <-refresh:
            metrics, err := xeth.Call("debug_metrics", []interface{}{true})
            if err != nil {
                utils.Fatalf("Failed to retrieve system metrics: %v", err)
            }
            for i, metric := range monitored {
                data[i] = append([]float64{value(metrics, metric)}, data[i][:len(data[i])-1]...)
                updateChart(metric, data[i], charts[i])
            }
            termui.Render(termui.Body)
        }
    }
}

// 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
}

// 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) {
    units := []string{"", "K", "M", "G", "T", "E", "P"}
    colors := []termui.Attribute{termui.ColorBlue, termui.ColorCyan, termui.ColorGreen, termui.ColorYellow, termui.ColorRed, termui.ColorRed, termui.ColorRed}

    // 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
    if unit > 0 {
        chart.Border.Label += " [" + units[unit] + "]"
    }
    chart.LineColor = colors[unit]
}