You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
306 lines
7.6 KiB
306 lines
7.6 KiB
// eventmeter - generic system to subscribe to events and record their frequency.
|
|
package eventmeter
|
|
|
|
import (
|
|
"context"
|
|
"encoding/json"
|
|
"fmt"
|
|
"sync"
|
|
"time"
|
|
|
|
metrics "github.com/rcrowley/go-metrics"
|
|
client "github.com/tendermint/tendermint/rpc/lib/client"
|
|
"github.com/tendermint/tmlibs/events"
|
|
"github.com/tendermint/tmlibs/log"
|
|
)
|
|
|
|
const (
|
|
// Get ping/pong latency and call LatencyCallbackFunc with this period.
|
|
latencyPeriod = 1 * time.Second
|
|
|
|
// Check if the WS client is connected every
|
|
connectionCheckPeriod = 100 * time.Millisecond
|
|
)
|
|
|
|
// EventMetric exposes metrics for an event.
|
|
type EventMetric struct {
|
|
ID string `json:"id"`
|
|
Started time.Time `json:"start_time"`
|
|
LastHeard time.Time `json:"last_heard"`
|
|
MinDuration int64 `json:"min_duration"`
|
|
MaxDuration int64 `json:"max_duration"`
|
|
|
|
// tracks event count and rate
|
|
meter metrics.Meter
|
|
|
|
// filled in from the Meter
|
|
Count int64 `json:"count"`
|
|
Rate1 float64 `json:"rate_1" wire:"unsafe"`
|
|
Rate5 float64 `json:"rate_5" wire:"unsafe"`
|
|
Rate15 float64 `json:"rate_15" wire:"unsafe"`
|
|
RateMean float64 `json:"rate_mean" wire:"unsafe"`
|
|
|
|
// so the event can have effects in the eventmeter's consumer. runs in a go
|
|
// routine.
|
|
callback EventCallbackFunc
|
|
}
|
|
|
|
func (metric *EventMetric) Copy() *EventMetric {
|
|
metricCopy := *metric
|
|
metricCopy.meter = metric.meter.Snapshot()
|
|
return &metricCopy
|
|
}
|
|
|
|
// called on GetMetric
|
|
func (metric *EventMetric) fillMetric() *EventMetric {
|
|
metric.Count = metric.meter.Count()
|
|
metric.Rate1 = metric.meter.Rate1()
|
|
metric.Rate5 = metric.meter.Rate5()
|
|
metric.Rate15 = metric.meter.Rate15()
|
|
metric.RateMean = metric.meter.RateMean()
|
|
return metric
|
|
}
|
|
|
|
// EventCallbackFunc is a closure to enable side effects from receiving an
|
|
// event.
|
|
type EventCallbackFunc func(em *EventMetric, data interface{})
|
|
|
|
// EventUnmarshalFunc is a closure to get the eventType and data out of the raw
|
|
// JSON received over the RPC WebSocket.
|
|
type EventUnmarshalFunc func(b json.RawMessage) (string, events.EventData, error)
|
|
|
|
// LatencyCallbackFunc is a closure to enable side effects from receiving a latency.
|
|
type LatencyCallbackFunc func(meanLatencyNanoSeconds float64)
|
|
|
|
// DisconnectCallbackFunc is a closure to notify a consumer that the connection
|
|
// has died.
|
|
type DisconnectCallbackFunc func()
|
|
|
|
// EventMeter tracks events, reports latency and disconnects.
|
|
type EventMeter struct {
|
|
wsc *client.WSClient
|
|
|
|
mtx sync.Mutex
|
|
events map[string]*EventMetric
|
|
|
|
unmarshalEvent EventUnmarshalFunc
|
|
latencyCallback LatencyCallbackFunc
|
|
disconnectCallback DisconnectCallbackFunc
|
|
subscribed bool
|
|
|
|
quit chan struct{}
|
|
|
|
logger log.Logger
|
|
}
|
|
|
|
func NewEventMeter(addr string, unmarshalEvent EventUnmarshalFunc) *EventMeter {
|
|
return &EventMeter{
|
|
wsc: client.NewWSClient(addr, "/websocket", client.PingPeriod(1*time.Second)),
|
|
events: make(map[string]*EventMetric),
|
|
unmarshalEvent: unmarshalEvent,
|
|
logger: log.NewNopLogger(),
|
|
}
|
|
}
|
|
|
|
// SetLogger lets you set your own logger.
|
|
func (em *EventMeter) SetLogger(l log.Logger) {
|
|
em.logger = l
|
|
em.wsc.SetLogger(l.With("module", "rpcclient"))
|
|
}
|
|
|
|
// String returns a string representation of event meter.
|
|
func (em *EventMeter) String() string {
|
|
return em.wsc.Address
|
|
}
|
|
|
|
// Start boots up event meter.
|
|
func (em *EventMeter) Start() error {
|
|
if _, err := em.wsc.Start(); err != nil {
|
|
return err
|
|
}
|
|
|
|
em.quit = make(chan struct{})
|
|
go em.receiveRoutine()
|
|
go em.disconnectRoutine()
|
|
|
|
err := em.subscribe()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
em.subscribed = true
|
|
return nil
|
|
}
|
|
|
|
// Stop stops event meter.
|
|
func (em *EventMeter) Stop() {
|
|
close(em.quit)
|
|
|
|
if em.wsc.IsRunning() {
|
|
em.wsc.Stop()
|
|
}
|
|
}
|
|
|
|
// Subscribe for the given event type. Callback function will be called upon
|
|
// receiving an event.
|
|
func (em *EventMeter) Subscribe(eventType string, cb EventCallbackFunc) error {
|
|
em.mtx.Lock()
|
|
defer em.mtx.Unlock()
|
|
|
|
if _, ok := em.events[eventType]; ok {
|
|
return fmt.Errorf("subscribtion already exists")
|
|
}
|
|
if err := em.wsc.Subscribe(context.TODO(), eventType); err != nil {
|
|
return err
|
|
}
|
|
|
|
metric := &EventMetric{
|
|
meter: metrics.NewMeter(),
|
|
callback: cb,
|
|
}
|
|
em.events[eventType] = metric
|
|
return nil
|
|
}
|
|
|
|
// Unsubscribe from the given event type.
|
|
func (em *EventMeter) Unsubscribe(eventType string) error {
|
|
em.mtx.Lock()
|
|
defer em.mtx.Unlock()
|
|
if err := em.wsc.Unsubscribe(context.TODO(), eventType); err != nil {
|
|
return err
|
|
}
|
|
// XXX: should we persist or save this info first?
|
|
delete(em.events, eventType)
|
|
return nil
|
|
}
|
|
|
|
// GetMetric fills in the latest data for an event and return a copy.
|
|
func (em *EventMeter) GetMetric(eventType string) (*EventMetric, error) {
|
|
em.mtx.Lock()
|
|
defer em.mtx.Unlock()
|
|
metric, ok := em.events[eventType]
|
|
if !ok {
|
|
return nil, fmt.Errorf("unknown event: %s", eventType)
|
|
}
|
|
return metric.fillMetric().Copy(), nil
|
|
}
|
|
|
|
// RegisterLatencyCallback allows you to set latency callback.
|
|
func (em *EventMeter) RegisterLatencyCallback(f LatencyCallbackFunc) {
|
|
em.mtx.Lock()
|
|
defer em.mtx.Unlock()
|
|
em.latencyCallback = f
|
|
}
|
|
|
|
// RegisterDisconnectCallback allows you to set disconnect callback.
|
|
func (em *EventMeter) RegisterDisconnectCallback(f DisconnectCallbackFunc) {
|
|
em.mtx.Lock()
|
|
defer em.mtx.Unlock()
|
|
em.disconnectCallback = f
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// Private
|
|
|
|
func (em *EventMeter) subscribe() error {
|
|
for eventType, _ := range em.events {
|
|
if err := em.wsc.Subscribe(context.TODO(), eventType); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (em *EventMeter) receiveRoutine() {
|
|
latencyTicker := time.NewTicker(latencyPeriod)
|
|
for {
|
|
select {
|
|
case rawEvent := <-em.wsc.ResultsCh:
|
|
if rawEvent == nil {
|
|
em.logger.Error("expected some event, got nil")
|
|
continue
|
|
}
|
|
eventType, data, err := em.unmarshalEvent(rawEvent)
|
|
if err != nil {
|
|
em.logger.Error("failed to unmarshal event", "err", err)
|
|
continue
|
|
}
|
|
if eventType != "" { // FIXME how can it be an empty string?
|
|
em.updateMetric(eventType, data)
|
|
}
|
|
case err := <-em.wsc.ErrorsCh:
|
|
if err != nil {
|
|
em.logger.Error("expected some event, got error", "err", err)
|
|
}
|
|
case <-latencyTicker.C:
|
|
if em.wsc.IsActive() {
|
|
em.callLatencyCallback(em.wsc.PingPongLatencyTimer.Mean())
|
|
}
|
|
case <-em.wsc.Quit:
|
|
return
|
|
case <-em.quit:
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
func (em *EventMeter) disconnectRoutine() {
|
|
ticker := time.NewTicker(connectionCheckPeriod)
|
|
for {
|
|
select {
|
|
case <-ticker.C:
|
|
if em.wsc.IsReconnecting() && em.subscribed { // notify user about disconnect only once
|
|
em.callDisconnectCallback()
|
|
em.subscribed = false
|
|
} else if !em.wsc.IsReconnecting() && !em.subscribed { // resubscribe
|
|
em.subscribe()
|
|
em.subscribed = true
|
|
}
|
|
case <-em.wsc.Quit:
|
|
return
|
|
case <-em.quit:
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
func (em *EventMeter) updateMetric(eventType string, data events.EventData) {
|
|
em.mtx.Lock()
|
|
defer em.mtx.Unlock()
|
|
|
|
metric, ok := em.events[eventType]
|
|
if !ok {
|
|
// we already unsubscribed, or got an unexpected event
|
|
return
|
|
}
|
|
|
|
last := metric.LastHeard
|
|
metric.LastHeard = time.Now()
|
|
metric.meter.Mark(1)
|
|
dur := int64(metric.LastHeard.Sub(last))
|
|
if dur < metric.MinDuration {
|
|
metric.MinDuration = dur
|
|
}
|
|
if !last.IsZero() && dur > metric.MaxDuration {
|
|
metric.MaxDuration = dur
|
|
}
|
|
|
|
if metric.callback != nil {
|
|
go metric.callback(metric.Copy(), data)
|
|
}
|
|
}
|
|
|
|
func (em *EventMeter) callDisconnectCallback() {
|
|
em.mtx.Lock()
|
|
if em.disconnectCallback != nil {
|
|
go em.disconnectCallback()
|
|
}
|
|
em.mtx.Unlock()
|
|
}
|
|
|
|
func (em *EventMeter) callLatencyCallback(meanLatencyNanoSeconds float64) {
|
|
em.mtx.Lock()
|
|
if em.latencyCallback != nil {
|
|
go em.latencyCallback(meanLatencyNanoSeconds)
|
|
}
|
|
em.mtx.Unlock()
|
|
}
|