Bug fixing

+ DB access is now right and uses copied sessions
+ DB session is now specifying the safe state and the mode
+ Fixed the issue with too early ICCC messages regarding to late cache
+ Add the MIME type for Dart
+ Fixed the issuse with wrong order of shutdown handlers
- TODO: Testing of these changes

CustomerDB/AccessDB.go

@@ -5,15 +5,22 @@ import "labix.org/v2/mgo"
 /*
 Get the database instance of the MGo Mongo driver.
 */
-func DB() (result *mgo.Database) {
-	result = db
+func DB() (session *mgo.Session, database *mgo.Database) {
+	session = mainSession.Copy()
+	database = session.DB(databaseDB)
+	database.Login(databaseUsername, databasePassword)
+
 	return
 }
 
 /*
 Get directly the GridFS instance of the Mgo Mongo driver.
 */
-func GridFS() (result *mgo.GridFS) {
-	result = gridFS
+func GridFS() (session *mgo.Session, filesystem *mgo.GridFS) {
+	session = mainSession.Copy()
+	database := session.DB(databaseDB)
+	database.Login(databaseUsername, databasePassword)
+	filesystem = database.GridFS(`fs`)
+
 	return
 }

CustomerDB/Init.go

@@ -10,20 +10,20 @@ func init() {
 	Log.LogShort(senderName, LM.CategorySYSTEM, LM.LevelINFO, LM.MessageNameDATABASE, `Init the customer database.`)
 
 	databaseHost := ConfigurationDB.Read(`CustomerDBHost`)
-	databaseDB := ConfigurationDB.Read(`CustomerDBDatabase`)
-	databaseUsername := ConfigurationDB.Read(`CustomerDBUsername`)
-	databasePassword := ConfigurationDB.Read(`CustomerDBPassword`)
+	databaseDB = ConfigurationDB.Read(`CustomerDBDatabase`)
+	databaseUsername = ConfigurationDB.Read(`CustomerDBUsername`)
+	databasePassword = ConfigurationDB.Read(`CustomerDBPassword`)
 
 	// Connect to MongoDB:
 	if newSession, errDial := mgo.Dial(databaseHost); errDial != nil {
 		Log.LogFull(senderName, LM.CategorySYSTEM, LM.LevelERROR, LM.SeverityUnknown, LM.ImpactUnknown, LM.MessageNameDATABASE, `It was not possible to connect to the MongoDB host `+databaseHost, errDial.Error())
 		return
 	} else {
-		session = newSession
+		mainSession = newSession
 	}
 
 	// Use the correct database:
-	db = session.DB(databaseDB)
+	db := mainSession.DB(databaseDB)
 	if db == nil {
 		Log.LogFull(senderName, LM.CategorySYSTEM, LM.LevelERROR, LM.SeverityCritical, LM.ImpactCritical, LM.MessageNameDATABASE, `Was not able to get the customer database.`)
 		return
@@ -35,8 +35,15 @@ func init() {
 		return
 	}
 
+	// In case of write operations, wait for the majority of servers to be done:
+	mainSession.SetSafe(&mgo.Safe{WMode: "majority"})
+
+	// Set the consistency mode to read from any secondary server and write to the primary.
+	// Copied sessions can overwrite this setting of necessary.
+	mainSession.SetMode(mgo.Eventual, true)
+
 	// Get the GridFS:
-	gridFS = db.GridFS(`fs`)
+	gridFS := db.GridFS(`fs`)
 	if gridFS == nil {
 		Log.LogFull(senderName, LM.CategorySYSTEM, LM.LevelERROR, LM.SeverityCritical, LM.ImpactCritical, LM.MessageNameDATABASE, `Was not able to get the GridFS from the database.`)
 		return

CustomerDB/Shutdown.go

@@ -14,6 +14,4 @@ This function is called if the Ocean server is shutting down.
 */
 func (a ShutdownFunction) Shutdown() {
 	Log.LogShort(senderName, LM.CategoryAPP, LM.LevelWARN, LM.MessageNameSHUTDOWN, `Close now the customer database connection.`)
-	db.Logout()
-	session.Close()
 }

CustomerDB/Variables.go

@@ -4,8 +4,9 @@ import "labix.org/v2/mgo"
 import LM "github.com/SommerEngineering/Ocean/Log/Meta"
 
 var (
-	session    *mgo.Session  = nil
-	db         *mgo.Database = nil
-	gridFS     *mgo.GridFS   = nil
-	senderName LM.Sender     = `System::CustomerDB`
+	mainSession      *mgo.Session = nil
+	senderName       LM.Sender    = `System::CustomerDB`
+	databaseUsername string       = ``
+	databasePassword string       = ``
+	databaseDB       string       = ``
 )

ICCC/Doc.go

@@ -1,4 +1,4 @@
 /*
-This is the "[I]nter Data [C]enter Se[c]ure [C]ommunication" :)
+This is the "[I]nter Data [C]enter and Appli[c]ation [C]ommunication"
 */
 package ICCC

ICCC/Init.go

@@ -21,5 +21,6 @@ func init() {
 
 	initDB()
 	registerHost2Database()
+	cacheTimerLogic(false)
 	initCacheTimer()
 }

ICCC/InitDB.go

@@ -10,7 +10,7 @@ func initDB() {
 	defer Log.LogShort(senderName, LM.CategorySYSTEM, LM.LevelINFO, LM.MessageNameINIT, `Done init the ICCC collection.`)
 
 	// Get the database:
-	db = CustomerDB.DB()
+	dbSession, db = CustomerDB.DB()
 
 	if db == nil {
 		Log.LogFull(senderName, LM.CategorySYSTEM, LM.LevelERROR, LM.SeverityCritical, LM.ImpactCritical, LM.MessageNameDATABASE, `Was not able to get the customer database.`)

ICCC/ListenerCache.go

@@ -9,33 +9,38 @@ import "github.com/SommerEngineering/Ocean/Log"
 import LM "github.com/SommerEngineering/Ocean/Log/Meta"
 
 func initCacheTimer() {
-
 	go func() {
 		for {
-
-			if Shutdown.IsDown() {
-				return
-			}
-
-			lastCount := cacheListenerDatabase.Len()
-			selection := bson.D{{`IsActive`, true}}
-			entriesIterator := collectionListener.Find(selection).Iter()
-			entry := Scheme.Listener{}
-
-			cacheListenerDatabaseLock.Lock()
-			cacheListenerDatabase.Init()
-			for entriesIterator.Next(&entry) {
-				cacheListenerDatabase.PushBack(entry)
-			}
-
-			cacheListenerDatabaseLock.Unlock()
-			nextDuration := time.Duration(5) * time.Minute
-			if cacheListenerDatabase.Len() == 0 {
-				nextDuration = time.Duration(10) * time.Second
-			}
-
-			Log.LogShort(senderName, LM.CategorySYSTEM, LM.LevelINFO, LM.MessageNameEXECUTE, `The listener cache was refreshed with the values from the database.`, fmt.Sprintf(`last count=%d`, lastCount), fmt.Sprintf(`new count=%d`, cacheListenerDatabase.Len()))
-			time.Sleep(nextDuration)
+			cacheTimerLogic(true)
 		}
 	}()
 }
+
+func cacheTimerLogic(waiting bool) {
+	if Shutdown.IsDown() {
+		return
+	}
+
+	lastCount := cacheListenerDatabase.Len()
+	selection := bson.D{{`IsActive`, true}}
+	entriesIterator := collectionListener.Find(selection).Iter()
+	entry := Scheme.Listener{}
+
+	cacheListenerDatabaseLock.Lock()
+	cacheListenerDatabase.Init()
+	for entriesIterator.Next(&entry) {
+		cacheListenerDatabase.PushBack(entry)
+	}
+
+	cacheListenerDatabaseLock.Unlock()
+	Log.LogShort(senderName, LM.CategorySYSTEM, LM.LevelINFO, LM.MessageNameEXECUTE, `The listener cache was refreshed with the values from the database.`, fmt.Sprintf(`last count=%d`, lastCount), fmt.Sprintf(`new count=%d`, cacheListenerDatabase.Len()))
+
+	if waiting {
+		nextDuration := time.Duration(5) * time.Minute
+		if cacheListenerDatabase.Len() == 0 {
+			nextDuration = time.Duration(10) * time.Second
+		}
+
+		time.Sleep(nextDuration)
+	}
+}

ICCC/Shutdown.go

@@ -26,5 +26,7 @@ func (a ShutdownFunction) Shutdown() {
 		collectionListener.Update(selectionUpdate, entry)
 	}
 
+	db.Logout()
+	dbSession.Close()
 	Log.LogShort(senderName, LM.CategoryAPP, LM.LevelWARN, LM.MessageNameSHUTDOWN, `Done shutting down now all ICCC listener for this host.`)
 }

ICCC/Variables.go

@@ -16,6 +16,7 @@ const (
 var (
 	senderName                LM.Sender                                 = `ICCC`
 	db                        *mgo.Database                             = nil
+	dbSession                 *mgo.Session                              = nil
 	collectionListener        *mgo.Collection                           = nil
 	collectionHosts           *mgo.Collection                           = nil
 	reservedSystemChannels    []string                                  = []string{ChannelSYSTEM, ChannelNUMGEN, ChannelSHUTDOWN, ChannelSTARTUP, ChannelICCC}

MimeTypes/KnownTypes.go

@@ -3,6 +3,7 @@ package MimeTypes
 var TypeWebHTML = MimeType{MimeType: "text/html", FileExtension: []string{".html", ".htm"}}
 var TypeWebCSS = MimeType{MimeType: "text/css", FileExtension: []string{".css"}}
 var TypeWebJavaScript = MimeType{MimeType: "text/javascript", FileExtension: []string{".js"}}
+var TypeWebDart = MimeType{MimeType: "application/dart", FileExtension: []string{".dart"}}
 var TypeXML = MimeType{MimeType: "text/xml", FileExtension: []string{".xml"}}
 var TypeArchiveZIP = MimeType{MimeType: "application/zip", FileExtension: []string{".zip"}}
 var TypeArchiveGZ = MimeType{MimeType: "application/gzip", FileExtension: []string{".gz"}}

NumGen/InitDB.go

@@ -10,7 +10,7 @@ func initDB() {
 	defer Log.LogShort(senderName, LM.CategorySYSTEM, LM.LevelINFO, LM.MessageNameINIT, `Done init of number generator collection.`)
 
 	// Get the database:
-	db = CustomerDB.DB()
+	dbSession, db = CustomerDB.DB()
 
 	if db == nil {
 		Log.LogFull(senderName, LM.CategorySYSTEM, LM.LevelERROR, LM.SeverityCritical, LM.ImpactCritical, LM.MessageNameDATABASE, `Was not able to get the customer database.`)

NumGen/Shutdown.go

@@ -8,4 +8,6 @@ type ShutdownFunction struct {
 
 func (a ShutdownFunction) Shutdown() {
 	Log.LogShort(senderName, LM.CategoryAPP, LM.LevelWARN, LM.MessageNameSHUTDOWN, `Shutting down the number generator.`)
+	db.Logout()
+	dbSession.Close()
 }

NumGen/Variables.go

@@ -10,6 +10,7 @@ var (
 	isActive          bool                  = false
 	getHandler        string                = ``
 	db                *mgo.Database         = nil
+	dbSession         *mgo.Session          = nil
 	collectionNumGen  *mgo.Collection       = nil
 	channelBufferSize int                   = 10
 	channelList       map[string]chan int64 = nil

Shutdown/Shutdown.go

@@ -9,7 +9,7 @@ type ShutdownHandler interface {
 }
 
 func AddShutdownHandler(handler ShutdownHandler) {
-	shutdownHandlers.PushBack(handler)
+	shutdownHandlers.PushFront(handler)
 }
 
 func executeShutdown() {

StaticFiles/Init.go

@@ -26,7 +26,9 @@ func init() {
 	logStaticFileRequests = ConfigurationDB.Read(`LogStaticFileRequests`) == `true`
 
 	// Read the static files' data from GridFS:
-	gridFS := CustomerDB.GridFS()
+	dbSession, gridFS := CustomerDB.GridFS()
+	defer dbSession.Close()
+
 	if gridFile, errGridFile := gridFS.Open(`staticFiles.zip`); errGridFile != nil {
 		Log.LogFull(senderName, LM.CategorySYSTEM, LM.LevelERROR, LM.SeverityCritical, LM.ImpactCritical, LM.MessageNameDATABASE, `Was not able to open the static files out of the GridFS!`, errGridFile.Error())
 		return

System/Init.go

@@ -78,11 +78,17 @@ func initSystem() {
 	Log.LoggingIsReady()
 
 	// Register all system shutdown handlers:
+	//
+	// Please notice: If the shutdown event occurs ...
+	//		* all application handlers are called (order: last comed, first served)
+	//		* then, these system handlers are called (order: last comed, first served)
+	//		* and finally, the logging device / system gets closed
 	Shutdown.InitShutdown()
 	Shutdown.AddShutdownHandler(ICCC.ShutdownFunction{})
 	Shutdown.AddShutdownHandler(NumGen.ShutdownFunction{})
 	Shutdown.AddShutdownHandler(ConfigurationDB.ShutdownFunction{})
 	Shutdown.AddShutdownHandler(CustomerDB.ShutdownFunction{})
+
 	// The logging subsystem is not registered here, because it will be automated called at the end
 
 	// Register all system ICCC commands:

Templates/Init.go

@@ -13,7 +13,9 @@ func init() {
 	Log.LogShort(senderName, LM.CategorySYSTEM, LM.LevelINFO, LM.MessageNameSTARTUP, `Starting the template engine.`)
 	defer Log.LogShort(senderName, LM.CategorySYSTEM, LM.LevelINFO, LM.MessageNameSTARTUP, `Starting the template engine done.`)
 
-	gridFS := CustomerDB.GridFS()
+	dbSession, gridFS := CustomerDB.GridFS()
+	defer dbSession.Close()
+
 	if gridFile, errGridFile := gridFS.Open(`templates.zip`); errGridFile != nil {
 		Log.LogFull(senderName, LM.CategorySYSTEM, LM.LevelERROR, LM.SeverityCritical, LM.ImpactCritical, LM.MessageNameDATABASE, `Was not able to open the templates out of the GridFS!`, errGridFile.Error())
 		return

WebContent/Init.go

@@ -17,7 +17,8 @@ func init() {
 	}
 
 	filename = ConfigurationDB.Read(`FilenameWebResources`)
-	gridFS := CustomerDB.GridFS()
+	dbSession, gridFS := CustomerDB.GridFS()
+	defer dbSession.Close()
 
 	if gridFile, errGridFile := gridFS.Open(filename); errGridFile != nil {
 		Log.LogFull(senderName, LM.CategorySYSTEM, LM.LevelERROR, LM.SeverityCritical, LM.ImpactCritical, LM.MessageNameDATABASE, `Was not able to open the web content out of the GridFS!`, filename, errGridFile.Error())