MM-16378: revert plugin health check config removal (#11819)

* revert 4e5f6fcfbc

This reverts the configuration setting to disable plugin health checks, preferring instead to retain this functionality for advanced cases. In part, this was driven by the discovery that the health checks were failing on Windows, though that will be addressed separately.

Fixes: MM-16378

* simplify interval handling/logging

Also shutdown the job when plugins are altogether disabled.

app/diagnostics.go

@@ -597,6 +597,7 @@ func (a *App) trackConfig() {
 		"enable":                        *cfg.PluginSettings.Enable,
 		"enable_uploads":                *cfg.PluginSettings.EnableUploads,
 		"allow_insecure_download_url":   *cfg.PluginSettings.AllowInsecureDownloadUrl,
+		"enable_health_check":           *cfg.PluginSettings.EnableHealthCheck,
 	})
 
 	a.SendDiagnostic(TRACK_CONFIG_DATA_RETENTION, map[string]interface{}{

app/server.go

@@ -204,8 +204,14 @@ func NewServer(options ...Option) (*Server, error) {
 	// Start plugin health check job
 	pluginsEnvironment := s.PluginsEnvironment
 	if pluginsEnvironment != nil {
-		pluginsEnvironment.InitPluginHealthCheckJob()
+		pluginsEnvironment.InitPluginHealthCheckJob(*s.Config().PluginSettings.Enable && *s.Config().PluginSettings.EnableHealthCheck)
 	}
+	s.AddConfigListener(func(_, c *model.Config) {
+		pluginsEnvironment := s.PluginsEnvironment
+		if pluginsEnvironment != nil {
+			pluginsEnvironment.InitPluginHealthCheckJob(*s.Config().PluginSettings.Enable && *c.PluginSettings.EnableHealthCheck)
+		}
+	})
 
 	mlog.Info(fmt.Sprintf("Current version is %v (%v/%v/%v/%v)", model.CurrentVersion, model.BuildNumber, model.BuildDate, model.BuildHash, model.BuildHashEnterprise))
 	mlog.Info(fmt.Sprintf("Enterprise Enabled: %v", model.BuildEnterpriseReady))

mlog/log.go

@@ -34,6 +34,7 @@ var String = zap.String
 var Any = zap.Any
 var Err = zap.Error
 var Bool = zap.Bool
+var Duration = zap.Duration
 
 type LoggerConfiguration struct {
 	EnableConsole bool

model/config.go

@@ -2187,6 +2187,7 @@ type PluginSettings struct {
 	Enable                   *bool
 	EnableUploads            *bool   `restricted:"true"`
 	AllowInsecureDownloadUrl *bool   `restricted:"true"`
+	EnableHealthCheck        *bool   `restricted:"true"`
 	Directory                *string `restricted:"true"`
 	ClientDirectory          *string `restricted:"true"`
 	Plugins                  map[string]map[string]interface{}
@@ -2206,6 +2207,10 @@ func (s *PluginSettings) SetDefaults(ls LogSettings) {
 		s.AllowInsecureDownloadUrl = NewBool(false)
 	}
 
+	if s.EnableHealthCheck == nil {
+		s.EnableHealthCheck = NewBool(true)
+	}
+
 	if s.Directory == nil {
 		s.Directory = NewString(PLUGIN_SETTINGS_DEFAULT_DIRECTORY)
 	}

plugin/health_check.go

@@ -12,10 +12,10 @@ import (
 )
 
 const (
-	HEALTH_CHECK_INTERVAL         = 30 // seconds. How often the health check should run
+	HEALTH_CHECK_INTERVAL         = 30 * time.Second // How often the health check should run
-	HEALTH_CHECK_DISABLE_DURATION = 60 // minutes. How long we wait for num fails to incur before disabling the plugin
+	HEALTH_CHECK_DISABLE_DURATION = 60 * time.Minute // How long we wait for num fails to incur before disabling the plugin
-	HEALTH_CHECK_PING_FAIL_LIMIT  = 3  // How many times we call RPC ping in a row before it is considered a failure
+	HEALTH_CHECK_PING_FAIL_LIMIT  = 3                // How many times we call RPC ping in a row before it is considered a failure
-	HEALTH_CHECK_RESTART_LIMIT    = 3  // How many times we restart a plugin before we disable it
+	HEALTH_CHECK_RESTART_LIMIT    = 3                // How many times we restart a plugin before we disable it
 )
 
 type PluginHealthCheckJob struct {
@@ -24,22 +24,34 @@ type PluginHealthCheckJob struct {
 	env       *Environment
 }
 
-// InitPluginHealthCheckJob starts a new job for checking all active plugins
+// InitPluginHealthCheckJob starts a new job if one is not running and is set to enabled, or kills an existing one if set to disabled.
-func (env *Environment) InitPluginHealthCheckJob() {
+func (env *Environment) InitPluginHealthCheckJob(enable bool) {
-	job := newPluginHealthCheckJob(env)
+	// Config is set to enable. No job exists, start a new job.
-	env.pluginHealthCheckJob = job
+	if enable && env.pluginHealthCheckJob == nil {
-	job.Start()
+		mlog.Debug("Enabling plugin health check job", mlog.Duration("interval_s", HEALTH_CHECK_INTERVAL))
+
+		job := newPluginHealthCheckJob(env)
+		env.pluginHealthCheckJob = job
+		job.Start()
+	}
+
+	// Config is set to disable. Job exists, kill existing job.
+	if !enable && env.pluginHealthCheckJob != nil {
+		mlog.Debug("Disabling plugin health check job")
+
+		env.pluginHealthCheckJob.Cancel()
+		env.pluginHealthCheckJob = nil
+	}
 }
 
 // Start continuously runs health checks on all active plugins, on a timer.
 func (job *PluginHealthCheckJob) Start() {
-	interval := time.Duration(HEALTH_CHECK_INTERVAL) * time.Second
+	mlog.Debug("Plugin health check job starting.")
-	mlog.Debug(fmt.Sprintf("Plugin health check job starting. Sending health check pings every %v seconds.", interval))
 
 	go func() {
 		defer close(job.cancelled)
 
-		ticker := time.NewTicker(interval)
+		ticker := time.NewTicker(HEALTH_CHECK_INTERVAL)
 		defer func() {
 			ticker.Stop()
 		}()
@@ -125,7 +137,7 @@ func shouldDeactivatePlugin(rp *registeredPlugin) bool {
 		index := len(rp.failTimeStamps) - HEALTH_CHECK_RESTART_LIMIT
 		t := rp.failTimeStamps[index]
 		now := time.Now()
-		elapsed := now.Sub(t).Minutes()
+		elapsed := now.Sub(t)
 		if elapsed <= HEALTH_CHECK_DISABLE_DURATION {
 			return true
 		}

plugin/health_check_test.go

@@ -130,8 +130,8 @@ func TestShouldDeactivatePlugin(t *testing.T) {
 
 	// Failures are recent enough to restart
 	rp = newRegisteredPlugin(bundle)
-	rp.failTimeStamps = append(rp.failTimeStamps, now.Add(-HEALTH_CHECK_DISABLE_DURATION*0.2*time.Minute))
+	rp.failTimeStamps = append(rp.failTimeStamps, now.Add(-HEALTH_CHECK_DISABLE_DURATION/10*2))
-	rp.failTimeStamps = append(rp.failTimeStamps, now.Add(-HEALTH_CHECK_DISABLE_DURATION*0.1*time.Minute))
+	rp.failTimeStamps = append(rp.failTimeStamps, now.Add(-HEALTH_CHECK_DISABLE_DURATION/10))
 	rp.failTimeStamps = append(rp.failTimeStamps, now)
 
 	result = shouldDeactivatePlugin(rp)
@@ -139,8 +139,8 @@ func TestShouldDeactivatePlugin(t *testing.T) {
 
 	// Failures are too spaced out to warrant a restart
 	rp = newRegisteredPlugin(bundle)
-	rp.failTimeStamps = append(rp.failTimeStamps, now.Add(-HEALTH_CHECK_DISABLE_DURATION*2*time.Minute))
+	rp.failTimeStamps = append(rp.failTimeStamps, now.Add(-HEALTH_CHECK_DISABLE_DURATION*2))
-	rp.failTimeStamps = append(rp.failTimeStamps, now.Add(-HEALTH_CHECK_DISABLE_DURATION*1*time.Minute))
+	rp.failTimeStamps = append(rp.failTimeStamps, now.Add(-HEALTH_CHECK_DISABLE_DURATION*1))
 	rp.failTimeStamps = append(rp.failTimeStamps, now)
 
 	result = shouldDeactivatePlugin(rp)
@@ -148,7 +148,7 @@ func TestShouldDeactivatePlugin(t *testing.T) {
 
 	// Not enough failures are present to warrant a restart
 	rp = newRegisteredPlugin(bundle)
-	rp.failTimeStamps = append(rp.failTimeStamps, now.Add(-HEALTH_CHECK_DISABLE_DURATION*0.1*time.Minute))
+	rp.failTimeStamps = append(rp.failTimeStamps, now.Add(-HEALTH_CHECK_DISABLE_DURATION/10))
 	rp.failTimeStamps = append(rp.failTimeStamps, now)
 
 	result = shouldDeactivatePlugin(rp)