Throttle session creation in nwo.Network (#1111)

There are many places in the integration tests where the network will repeatedly poll for some condition using Fabric command line tools in an `Eventually`. When this pattern is used, the commands are executed every 10ms until until the polling expires or the condition is satisfied. While this works, the polling does not have to be run as frequently. This change introduces a `SessionCreateInterval` field to the network that can be used to influence how quickly the same command can be re-issued. The default value of 1s will reduce the frequency of CLI execution when used in an Eventually loop without impacting the polling on sessions or other activities. Signed-off-by: Matthew Sykes <matthew.sykes@gmail.com>
hyperledger · Apr 16, 2020 · 6cdbca8 · 6cdbca8
1 parent b86eadb
commit 6cdbca8
Showing 1 changed file with 62 additions and 11 deletions.
diff --git a/integration/nwo/network.go b/integration/nwo/network.go
@@ -136,16 +136,17 @@ type Profile struct {
 
 // Network holds information about a fabric network.
 type Network struct {
-	RootDir            string
-	StartPort          uint16
-	Components         *Components
-	DockerClient       *docker.Client
-	ExternalBuilders   []fabricconfig.ExternalBuilder
-	NetworkID          string
-	EventuallyTimeout  time.Duration
-	MetricsProvider    string
-	StatsdEndpoint     string
-	ClientAuthRequired bool
+	RootDir               string
+	StartPort             uint16
+	Components            *Components
+	DockerClient          *docker.Client
+	ExternalBuilders      []fabricconfig.ExternalBuilder
+	NetworkID             string
+	EventuallyTimeout     time.Duration
+	SessionCreateInterval time.Duration
+	MetricsProvider       string
+	StatsdEndpoint        string
+	ClientAuthRequired    bool
 
 	PortsByBrokerID  map[string]Ports
 	PortsByOrdererID map[string]Ports
@@ -160,7 +161,8 @@ type Network struct {
 	Consortiums      []*Consortium
 	Templates        *Templates
 
-	colorIndex uint
+	colorIndex       uint
+	sessLastExecuted map[string]time.Time
 }
 
 // New creates a Network from a simple configuration. All generated or managed
@@ -189,6 +191,8 @@ func New(c *Config, rootDir string, client *docker.Client, startPort int, compon
 		Profiles:      c.Profiles,
 		Consortiums:   c.Consortiums,
 		Templates:     c.Templates,
+
+		sessLastExecuted: make(map[string]time.Time),
 	}
 
 	cwd, err := os.Getwd()
@@ -202,6 +206,9 @@ func New(c *Config, rootDir string, client *docker.Client, startPort int, compon
 	if network.Templates == nil {
 		network.Templates = &Templates{}
 	}
+	if network.SessionCreateInterval == 0 {
+		network.SessionCreateInterval = time.Second
+	}
 
 	for i := 0; i < network.Consensus.Brokers; i++ {
 		ports := Ports{}
@@ -1548,9 +1555,53 @@ func (n *Network) nextColor() string {
 	return fmt.Sprintf("%dm", color)
 }
 
+func commandHash(cmd *exec.Cmd) string {
+	buf := bytes.NewBuffer(nil)
+	_, err := buf.WriteString(cmd.Dir)
+	Expect(err).NotTo(HaveOccurred())
+	_, err = buf.WriteString(cmd.Path)
+	Expect(err).NotTo(HaveOccurred())
+
+	// sort the environment since it's not positional
+	env := append([]string(nil), cmd.Env...)
+	sort.Strings(env)
+	for _, e := range env {
+		_, err := buf.WriteString(e)
+		Expect(err).NotTo(HaveOccurred())
+	}
+
+	// grab the args but ignore references to temporary files
+	for _, arg := range cmd.Args {
+		if strings.HasPrefix(arg, os.TempDir()) {
+			continue
+		}
+		_, err := buf.WriteString(arg)
+		Expect(err).NotTo(HaveOccurred())
+	}
+
+	return buf.String()
+}
+
+func (n *Network) sessionThrottleDuration(cmd *exec.Cmd) time.Duration {
+	h := commandHash(cmd)
+	now := time.Now()
+	last := n.sessLastExecuted[h]
+	n.sessLastExecuted[h] = now
+
+	if diff := last.Add(n.SessionCreateInterval).Sub(now); diff > 0 {
+		return diff
+	}
+
+	return 0
+}
+
 // StartSession executes a command session. This should be used to launch
 // command line tools that are expected to run to completion.
 func (n *Network) StartSession(cmd *exec.Cmd, name string) (*gexec.Session, error) {
+	if d := n.sessionThrottleDuration(cmd); d > 0 {
+		time.Sleep(d)
+	}
+
 	ansiColorCode := n.nextColor()
 	fmt.Fprintf(
 		ginkgo.GinkgoWriter,