functions: performance improvements - LRU & singleflight DB calls (#322)

* functions: add cache and singleflight to ease database load

* runner: upgrade

* deps: upgrade glide files

* license: add third party notifications

* functions: fix handling of implicitly created apps

* functions: code deduplication

* functions: fix missing variable

THIRD_PARTY

@@ -2,3 +2,7 @@ This software uses third-party software.
 
 For: api/server/tree.go
 Copyright 2013 Julien Schmidt. All rights reserved. BSD-license
+
+For: api/server/internal/routecache/lru.go
+For: api/server/singleflight.go
+Copyright 2012 Google Inc. All rights reserved. Apache 2 license

api/datastore/mock.go

@@ -65,7 +65,7 @@ func (m *Mock) GetRoutesByApp(appName string, routeFilter *models.RouteFilter) (
 	route := m.FakeRoute
 	if route == nil && m.FakeRoutes != nil {
 		for _, r := range m.FakeRoutes {
-			if r.AppName == appName && r.Path == routeFilter.Path && r.AppName == routeFilter.AppName {
+			if r.AppName == appName && (routeFilter.Path == "" || r.Path == routeFilter.Path) && (routeFilter.AppName == "" || r.AppName == routeFilter.AppName) {
 				routes = append(routes, r)
 			}
 		}

api/runner/async_runner.go

@@ -86,24 +86,12 @@ func deleteTask(url string, task *models.Task) error {
 
 // RunAsyncRunner pulls tasks off a queue and processes them
 func RunAsyncRunner(ctx context.Context, tasksrv string, tasks chan TaskRequest, rnr *Runner) {
-	u, h := tasksrvURL(tasksrv)
+	u := tasksrvURL(tasksrv)
-	if isHostOpen(h) {
-		return
-	}
 
 	startAsyncRunners(ctx, u, tasks, rnr)
 	<-ctx.Done()
 }
 
-func isHostOpen(host string) bool {
-	conn, err := net.Dial("tcp", host)
-	available := err == nil
-	if available {
-		conn.Close()
-	}
-	return available
-}
-
 func startAsyncRunners(ctx context.Context, url string, tasks chan TaskRequest, rnr *Runner) {
 	var wg sync.WaitGroup
 	ctx, log := common.LoggerWithFields(ctx, logrus.Fields{"runner": "async"})
@@ -159,15 +147,11 @@ func startAsyncRunners(ctx context.Context, url string, tasks chan TaskRequest,
 	}
 }
 
-func tasksrvURL(tasksrv string) (parsedURL, host string) {
+func tasksrvURL(tasksrv string) string {
 	parsed, err := url.Parse(tasksrv)
 	if err != nil {
-		logrus.WithError(err).Fatalln("cannot parse TASKSRV endpoint")
+		logrus.WithError(err).Fatalln("cannot parse API_URL endpoint")
 	}
-	// host, port, err := net.SplitHostPort(parsed.Host)
-	// if err != nil {
-	// 	log.WithError(err).Fatalln("net.SplitHostPort")
-	// }
 
 	if parsed.Scheme == "" {
 		parsed.Scheme = "http"
@@ -177,9 +161,5 @@ func tasksrvURL(tasksrv string) (parsedURL, host string) {
 		parsed.Path = "/tasks"
 	}
 
-	// if _, _, err := net.SplitHostPort(parsed.Host); err != nil {
+	return parsed.String()
-	// 	parsed.Host = net.JoinHostPort(parsed.Host, parsed)
-	// }
-
-	return parsed.String(), parsed.Host
 }

api/runner/async_runner_test.go

@@ -182,7 +182,7 @@ func TestTasksrvURL(t *testing.T) {
 	}
 
 	for _, tt := range tests {
-		if got, _ := tasksrvURL(tt.in); got != tt.out {
+		if got := tasksrvURL(tt.in); got != tt.out {
 			t.Errorf("tasksrv: %s\texpected: %s\tgot: %s\t", tt.in, tt.out, got)
 		}
 	}

api/runner/task.go

@@ -3,6 +3,7 @@ package runner
 import (
 	"context"
 	"io"
+	"time"
 
 	"github.com/fsouza/go-dockerclient"
 	"github.com/iron-io/runner/drivers"
@@ -32,7 +33,7 @@ func (t *containerTask) Labels() map[string]string {
 func (t *containerTask) Id() string                         { return t.cfg.ID }
 func (t *containerTask) Route() string                      { return "" }
 func (t *containerTask) Image() string                      { return t.cfg.Image }
-func (t *containerTask) Timeout() uint                      { return uint(t.cfg.Timeout.Seconds()) }
+func (t *containerTask) Timeout() time.Duration             { return t.cfg.Timeout }
 func (t *containerTask) Logger() (stdout, stderr io.Writer) { return t.cfg.Stdout, t.cfg.Stderr }
 func (t *containerTask) Volumes() [][2]string               { return [][2]string{} }
 func (t *containerTask) WorkDir() string                    { return "" }

api/server/apps_create.go

@@ -9,7 +9,7 @@ import (
 	"github.com/iron-io/runner/common"
 )
 
-func handleAppCreate(c *gin.Context) {
+func (s *Server) handleAppCreate(c *gin.Context) {
 	ctx := c.MustGet("ctx").(context.Context)
 	log := common.Logger(ctx)
 
@@ -55,5 +55,7 @@ func handleAppCreate(c *gin.Context) {
 		return
 	}
 
+	s.resetcache(wapp.App.Name, 1)
+
 	c.JSON(http.StatusCreated, appResponse{"App successfully created", wapp.App})
 }

api/server/internal/routecache/lru.go

@@ -0,0 +1,77 @@
+// Package routecache is meant to assist in resolving the most used routes at
+// an application. Implemented as a LRU, it returns always its full context for
+// iteration at the router handler.
+package routecache
+
+// based on groupcache's LRU
+
+import (
+	"container/list"
+
+	"github.com/iron-io/functions/api/models"
+)
+
+// Cache holds an internal linkedlist for hotness management. It is not safe
+// for concurrent use, must be guarded externally.
+type Cache struct {
+	MaxEntries int
+
+	ll    *list.List
+	cache map[string]*list.Element
+}
+
+// New returns a route cache.
+func New(maxentries int) *Cache {
+	return &Cache{
+		MaxEntries: maxentries,
+		ll:         list.New(),
+		cache:      make(map[string]*list.Element),
+	}
+}
+
+// Refresh updates internal linkedlist either adding a new route to the front,
+// or moving it to the front when used. It will discard seldom used routes.
+func (c *Cache) Refresh(route *models.Route) {
+	if c.cache == nil {
+		return
+	}
+
+	if ee, ok := c.cache[route.Path]; ok {
+		c.ll.MoveToFront(ee)
+		ee.Value = route
+		return
+	}
+
+	ele := c.ll.PushFront(route)
+	c.cache[route.Path] = ele
+	if c.MaxEntries != 0 && c.ll.Len() > c.MaxEntries {
+		c.removeOldest()
+	}
+}
+
+// Get looks up a path's route from the cache.
+func (c *Cache) Get(path string) (route *models.Route, ok bool) {
+	if c.cache == nil {
+		return
+	}
+	if ele, hit := c.cache[path]; hit {
+		c.ll.MoveToFront(ele)
+		return ele.Value.(*models.Route), true
+	}
+	return
+}
+
+func (c *Cache) removeOldest() {
+	if c.cache == nil {
+		return
+	}
+	if ele := c.ll.Back(); ele != nil {
+		c.removeElement(ele)
+	}
+}
+
+func (c *Cache) removeElement(e *list.Element) {
+	c.ll.Remove(e)
+	kv := e.Value.(*models.Route)
+	delete(c.cache, kv.Path)
+}

api/server/routes_create.go

@@ -10,7 +10,7 @@ import (
 	"github.com/iron-io/runner/common"
 )
 
-func handleRouteCreate(c *gin.Context) {
+func (s *Server) handleRouteCreate(c *gin.Context) {
 	ctx := c.MustGet("ctx").(context.Context)
 	log := common.Logger(ctx)
 
@@ -80,5 +80,7 @@ func handleRouteCreate(c *gin.Context) {
 		return
 	}
 
+	s.resetcache(wroute.Route.AppName, 1)
+
 	c.JSON(http.StatusCreated, routeResponse{"Route successfully created", wroute.Route})
 }

api/server/routes_delete.go

@@ -9,7 +9,7 @@ import (
 	"github.com/iron-io/runner/common"
 )
 
-func handleRouteDelete(c *gin.Context) {
+func (s *Server) handleRouteDelete(c *gin.Context) {
 	ctx := c.MustGet("ctx").(context.Context)
 	log := common.Logger(ctx)
 
@@ -23,5 +23,7 @@ func handleRouteDelete(c *gin.Context) {
 		return
 	}
 
+	s.resetcache(appName, 0)
+
 	c.JSON(http.StatusOK, gin.H{"message": "Route deleted"})
 }

api/server/runner.go

@@ -76,13 +76,11 @@ func (s *Server) handleRequest(c *gin.Context, enqueue models.Enqueue) {
 		c.JSON(http.StatusBadRequest, simpleError(models.ErrAppsNotFound))
 		return
 	}
-	route := c.Param("route")
+	path := c.Param("route")
-	if route == "" {
+	if path == "" {
-		route = c.Request.URL.Path
+		path = c.Request.URL.Path
 	}
 
-	log.WithFields(logrus.Fields{"app": appName, "path": route}).Debug("Finding route on datastore")
-
 	app, err := Api.Datastore.GetApp(appName)
 	if err != nil || app == nil {
 		log.WithError(err).Error(models.ErrAppsNotFound)
@@ -90,30 +88,56 @@ func (s *Server) handleRequest(c *gin.Context, enqueue models.Enqueue) {
 		return
 	}
 
-	routes, err := Api.Datastore.GetRoutesByApp(appName, &models.RouteFilter{AppName: appName, Path: route})
+	log.WithFields(logrus.Fields{"app": appName, "path": path}).Debug("Finding route on LRU cache")
+	route, ok := s.cacheget(appName, path)
+	if ok && s.serve(c, log, appName, route, app, path, reqID, payload, enqueue) {
+		s.refreshcache(appName, route)
+		return
+	}
+
+	log.WithFields(logrus.Fields{"app": appName, "path": path}).Debug("Finding route on datastore")
+	routes, err := s.loadroutes(models.RouteFilter{AppName: appName, Path: path})
 	if err != nil {
 		log.WithError(err).Error(models.ErrRoutesList)
 		c.JSON(http.StatusInternalServerError, simpleError(models.ErrRoutesList))
 		return
 	}
 
-	log.WithField("routes", routes).Debug("Got routes from datastore")
-
 	if len(routes) == 0 {
 		log.WithError(err).Error(models.ErrRunnerRouteNotFound)
 		c.JSON(http.StatusNotFound, simpleError(models.ErrRunnerRouteNotFound))
 		return
 	}
 
-	found := routes[0]
+	log.WithField("routes", len(routes)).Debug("Got routes from datastore")
-	log = log.WithFields(logrus.Fields{
+	route = routes[0]
-		"app": appName, "route": found.Path, "image": found.Image})
+	log = log.WithFields(logrus.Fields{"app": appName, "path": route.Path, "image": route.Image})
+
+	if s.serve(c, log, appName, route, app, path, reqID, payload, enqueue) {
+		s.refreshcache(appName, route)
+		return
+	}
+
+	log.Error(models.ErrRunnerRouteNotFound)
+	c.JSON(http.StatusNotFound, simpleError(models.ErrRunnerRouteNotFound))
+}
+
+func (s *Server) loadroutes(filter models.RouteFilter) ([]*models.Route, error) {
+	resp, err := s.singleflight.do(
+		filter,
+		func() (interface{}, error) {
+			return Api.Datastore.GetRoutesByApp(filter.AppName, &filter)
+		},
+	)
+	return resp.([]*models.Route), err
+}
+
+func (s *Server) serve(c *gin.Context, log logrus.FieldLogger, appName string, found *models.Route, app *models.App, route, reqID string, payload io.Reader, enqueue models.Enqueue) (ok bool) {
+	log = log.WithFields(logrus.Fields{"app": appName, "route": found.Path, "image": found.Image})
 
 	params, match := matchRoute(found.Path, route)
 	if !match {
-		log.WithError(err).Error(models.ErrRunnerRouteNotFound)
+		return false
-		c.JSON(http.StatusNotFound, simpleError(models.ErrRunnerRouteNotFound))
-		return
 	}
 
 	var stdout bytes.Buffer // TODO: should limit the size of this, error if gets too big. akin to: https://golang.org/pkg/io/#LimitReader
@@ -162,7 +186,7 @@ func (s *Server) handleRequest(c *gin.Context, enqueue models.Enqueue) {
 		if err != nil {
 			log.WithError(err).Error(models.ErrInvalidPayload)
 			c.JSON(http.StatusBadRequest, simpleError(models.ErrInvalidPayload))
-			return
+			return true
 		}
 
 		// Create Task
@@ -176,13 +200,12 @@ func (s *Server) handleRequest(c *gin.Context, enqueue models.Enqueue) {
 		task.EnvVars = cfg.Env
 		task.Payload = string(pl)
 		// Push to queue
-		enqueue(ctx, s.MQ, task)
+		enqueue(c, s.MQ, task)
 		log.Info("Added new task to queue")
 		c.JSON(http.StatusAccepted, map[string]string{"call_id": task.ID})
 
 	default:
-
+		result, err := runner.RunTask(s.tasks, c, cfg)
-		result, err := runner.RunTask(s.tasks, ctx, cfg)
 		if err != nil {
 			break
 		}
@@ -197,6 +220,8 @@ func (s *Server) handleRequest(c *gin.Context, enqueue models.Enqueue) {
 		}
 
 	}
+
+	return true
 }
 
 var fakeHandler = func(http.ResponseWriter, *http.Request, Params) {}

api/server/server.go

@@ -5,14 +5,17 @@ import (
 	"encoding/json"
 	"errors"
 	"io/ioutil"
+	"math"
 	"net/http"
 	"path"
+	"sync"
 
 	"github.com/Sirupsen/logrus"
 	"github.com/gin-gonic/gin"
 	"github.com/iron-io/functions/api/ifaces"
 	"github.com/iron-io/functions/api/models"
 	"github.com/iron-io/functions/api/runner"
+	"github.com/iron-io/functions/api/server/internal/routecache"
 	"github.com/iron-io/runner/common"
 )
 
@@ -23,13 +26,18 @@ var Api *Server
 type Server struct {
 	Runner          *runner.Runner
 	Router          *gin.Engine
-	Datastore       models.Datastore
 	MQ              models.MessageQueue
 	AppListeners    []ifaces.AppListener
 	SpecialHandlers []ifaces.SpecialHandler
 	Enqueue         models.Enqueue
 
 	tasks chan runner.TaskRequest
+
+	mu        sync.Mutex // protects hotroutes
+	hotroutes map[string]*routecache.Cache
+
+	singleflight singleflight // singleflight assists Datastore
+	Datastore    models.Datastore
 }
 
 func New(ctx context.Context, ds models.Datastore, mq models.MessageQueue, r *runner.Runner, tasks chan runner.TaskRequest, enqueue models.Enqueue) *Server {
@@ -38,6 +46,7 @@ func New(ctx context.Context, ds models.Datastore, mq models.MessageQueue, r *ru
 		Router:    gin.New(),
 		Datastore: ds,
 		MQ:        mq,
+		hotroutes: make(map[string]*routecache.Cache),
 		tasks:     tasks,
 		Enqueue:   enqueue,
 	}
@@ -47,10 +56,43 @@ func New(ctx context.Context, ds models.Datastore, mq models.MessageQueue, r *ru
 		c.Set("ctx", ctx)
 		c.Next()
 	})
+	Api.primeCache()
 
 	return Api
 }
 
+func (s *Server) primeCache() {
+	logrus.Info("priming cache with known routes")
+	apps, err := s.Datastore.GetApps(nil)
+	if err != nil {
+		logrus.WithError(err).Error("cannot prime cache - could not load application list")
+		return
+	}
+	for _, app := range apps {
+		routes, err := s.Datastore.GetRoutesByApp(app.Name, &models.RouteFilter{AppName: app.Name})
+		if err != nil {
+			logrus.WithError(err).WithField("appName", app.Name).Error("cannot prime cache - could not load routes")
+			continue
+		}
+
+		entries := len(routes)
+		// The idea here is to prevent both extremes: cache being too small that is ineffective,
+		// or too large that it takes too much memory. Up to 1k routes, the cache will try to hold
+		// all routes in the memory, thus taking up to 48K per application. After this threshold,
+		// it will keep 1024 routes + 20% of the total entries - in a hybrid incarnation of Pareto rule
+		// 1024+20% of the remaining routes will likelly be responsible for 80% of the workload.
+		if entries > cacheParetoThreshold {
+			entries = int(math.Ceil(float64(entries-1024)*0.2)) + 1024
+		}
+		s.hotroutes[app.Name] = routecache.New(entries)
+
+		for i := 0; i < entries; i++ {
+			s.refreshcache(app.Name, routes[i])
+		}
+	}
+	logrus.Info("cached prime")
+}
+
 // AddAppListener adds a listener that will be notified on App changes.
 func (s *Server) AddAppListener(listener ifaces.AppListener) {
 	s.AppListeners = append(s.AppListeners, listener)
@@ -105,6 +147,41 @@ func (s *Server) handleRunnerRequest(c *gin.Context) {
 	s.handleRequest(c, s.Enqueue)
 }
 
+// cacheParetoThreshold is both the mark from which the LRU starts caching only
+// the most likely hot routes, and also as a stopping mark for the cache priming
+// during start.
+const cacheParetoThreshold = 1024
+
+func (s *Server) cacheget(appname, path string) (*models.Route, bool) {
+	s.mu.Lock()
+	cache, ok := s.hotroutes[appname]
+	if !ok {
+		s.mu.Unlock()
+		return nil, false
+	}
+	route, ok := cache.Get(path)
+	s.mu.Unlock()
+	return route, ok
+}
+
+func (s *Server) refreshcache(appname string, route *models.Route) {
+	s.mu.Lock()
+	cache := s.hotroutes[appname]
+	cache.Refresh(route)
+	s.mu.Unlock()
+}
+
+func (s *Server) resetcache(appname string, delta int) {
+	s.mu.Lock()
+	hr, ok := s.hotroutes[appname]
+	if !ok {
+		s.hotroutes[appname] = routecache.New(0)
+		hr = s.hotroutes[appname]
+	}
+	s.hotroutes[appname] = routecache.New(hr.MaxEntries + delta)
+	s.mu.Unlock()
+}
+
 func (s *Server) handleTaskRequest(c *gin.Context) {
 	ctx, _ := common.LoggerWithFields(c, nil)
 	switch c.Request.Method {
@@ -164,7 +241,7 @@ func (s *Server) bindHandlers() {
 	v1 := engine.Group("/v1")
 	{
 		v1.GET("/apps", handleAppList)
-		v1.POST("/apps", handleAppCreate)
+		v1.POST("/apps", s.handleAppCreate)
 
 		v1.GET("/apps/:app", handleAppGet)
 		v1.PUT("/apps/:app", handleAppUpdate)
@@ -175,10 +252,10 @@ func (s *Server) bindHandlers() {
 		apps := v1.Group("/apps/:app")
 		{
 			apps.GET("/routes", handleRouteList)
-			apps.POST("/routes", handleRouteCreate)
+			apps.POST("/routes", s.handleRouteCreate)
 			apps.GET("/routes/*route", handleRouteGet)
 			apps.PUT("/routes/*route", handleRouteUpdate)
-			apps.DELETE("/routes/*route", handleRouteDelete)
+			apps.DELETE("/routes/*route", s.handleRouteDelete)
 		}
 	}
 

api/server/singleflight.go

@@ -0,0 +1,50 @@
+package server
+
+// Imported from https://github.com/golang/groupcache/blob/master/singleflight/singleflight.go
+
+import (
+	"sync"
+
+	"github.com/iron-io/functions/api/models"
+)
+
+// call is an in-flight or completed do call
+type call struct {
+	wg  sync.WaitGroup
+	val interface{}
+	err error
+}
+
+type singleflight struct {
+	mu sync.Mutex                   // protects m
+	m  map[models.RouteFilter]*call // lazily initialized
+}
+
+// do executes and returns the results of the given function, making
+// sure that only one execution is in-flight for a given key at a
+// time. If a duplicate comes in, the duplicate caller waits for the
+// original to complete and receives the same results.
+func (g *singleflight) do(key models.RouteFilter, fn func() (interface{}, error)) (interface{}, error) {
+	g.mu.Lock()
+	if g.m == nil {
+		g.m = make(map[models.RouteFilter]*call)
+	}
+	if c, ok := g.m[key]; ok {
+		g.mu.Unlock()
+		c.wg.Wait()
+		return c.val, c.err
+	}
+	c := new(call)
+	c.wg.Add(1)
+	g.m[key] = c
+	g.mu.Unlock()
+
+	c.val, c.err = fn()
+	c.wg.Done()
+
+	g.mu.Lock()
+	delete(g.m, key)
+	g.mu.Unlock()
+
+	return c.val, c.err
+}

glide.lock

@@ -1,5 +1,5 @@
-hash: 4acb4372011661fa4731e89ffd27714eb7ca6285a3d53c2f16f87c3a564d4d4e
+hash: a35b8b9511d2059122e72773c169b4dbbf9554dd9075ad55352facf7eae09895
-updated: 2016-11-02T11:42:34.9563341-07:00
+updated: 2016-11-20T20:18:19.564468442+01:00
 imports:
 - name: github.com/amir/raidman
   version: c74861fe6a7bb8ede0a010ce4485bdbb4fc4c985
@@ -25,16 +25,11 @@ imports:
   - aws/signer/v4
   - private/endpoints
   - private/protocol
-  - private/protocol/query
+  - private/protocol/json/jsonutil
-  - private/protocol/query/queryutil
+  - private/protocol/jsonrpc
   - private/protocol/rest
-  - private/protocol/restxml
+  - private/protocol/restjson
-  - private/protocol/xml/xmlutil
+  - service/lambda
-  - private/waiter
-  - service/cloudfront/sign
-  - service/s3
-  - vendor/github.com/go-ini/ini
-  - vendor/github.com/jmespath/go-jmespath
 - name: github.com/Azure/go-ansiterm
   version: fa152c58bc15761d0200cb75fe958b89a9d4888e
   subpackages:
@@ -61,8 +56,10 @@ imports:
   version: 4385816142116aade2d97d0f320f9d3666e74cd9
 - name: github.com/dghubble/sling
   version: c961a4334054e64299d16f8a31bd686ee2565ae4
+- name: github.com/dgrijalva/jwt-go
+  version: 9ed569b5d1ac936e6494082958d63a6aa4fff99a
 - name: github.com/docker/distribution
-  version: 6edf9c507051be36d82afbd71a3f2a7cdbbf4394
+  version: 99cb7c0946d2f5a38015443e515dc916295064d7
   subpackages:
   - context
   - digest
@@ -106,7 +103,7 @@ imports:
 - name: github.com/fsnotify/fsnotify
   version: fd9ec7deca8bf46ecd2a795baaacf2b3a9be1197
 - name: github.com/fsouza/go-dockerclient
-  version: 5cfde1d138cd2cdc13e4aa36af631beb19dcbe9c
+  version: ece08f96ac5f26f4073ab5c38f198c3e5000c554
 - name: github.com/garyburd/redigo
   version: 80f7de34463b0ed3d7c61303e5619efe1b227f92
   subpackages:
@@ -177,8 +174,6 @@ imports:
   version: 2a2e6b9e3eed0a98d438f111ba7469744c07281d
   subpackages:
   - registry
-- name: github.com/iron-io/functions_go
-  version: 584f4a6e13b53370f036012347cf0571128209f0
 - name: github.com/iron-io/iron_go3
   version: b50ecf8ff90187fc5fabccd9d028dd461adce4ee
   subpackages:
@@ -191,7 +186,7 @@ imports:
   subpackages:
   - lambda
 - name: github.com/iron-io/runner
-  version: 272e153e728eb4e0c1c92d908c463424dec78a73
+  version: 4101fd406ada3497c832d6877653262e23a84f1f
   repo: https://github.com/iron-io/runner.git
   vcs: git
   subpackages:
@@ -200,6 +195,8 @@ imports:
   - drivers
   - drivers/docker
   - drivers/mock
+- name: github.com/jmespath/go-jmespath
+  version: 3433f3ea46d9f8019119e7dd41274e112a2359a9
 - name: github.com/juju/errgo
   version: 08cceb5d0b5331634b9826762a8fd53b29b86ad8
   subpackages:
@@ -233,6 +230,8 @@ imports:
   version: df1e16fde7fc330a0ca68167c23bf7ed6ac31d6d
 - name: github.com/pelletier/go-toml
   version: 45932ad32dfdd20826f5671da37a5f3ce9f26a8d
+- name: github.com/pivotal-golang/bytefmt
+  version: b12c1522f4cbb5f35861bd5dd2c39a4fa996441a
 - name: github.com/pkg/errors
   version: 248dadf4e9068a0b3e79f02ed0a610d935de5302
 - name: github.com/pkg/sftp
@@ -244,7 +243,7 @@ imports:
 - name: github.com/satori/go.uuid
   version: 879c5887cd475cd7864858769793b2ceb0d44feb
 - name: github.com/Sirupsen/logrus
-  version: 4b6ea7319e214d98c938f12692336f7ca9348d6b
+  version: d26492970760ca5d33129d2d799e34be5c4782eb
   subpackages:
   - hooks/syslog
 - name: github.com/spf13/afero

main.go

@@ -76,6 +76,7 @@ func main() {
 	}
 
 	svr := &supervisor.Supervisor{
+		MaxRestarts: supervisor.AlwaysRestart,
 		Log: func(msg interface{}) {
 			log.Debug("supervisor: ", msg)
 		},