fix (MonitoringDB): make a MonitoringDB singleton

Author: chaen

src/DIRAC/MonitoringSystem/Client/ServerUtils.py

@@ -3,14 +3,14 @@
 It always try to insert the records directly. In case of failure the monitoring client is used...
 """
 
-from DIRAC.Core.Utilities.ServerUtils import getDBOrClient
+from DIRAC.Core.Base.Client import Client
+from DIRAC.MonitoringSystem.DB.MonitoringDB import gMonitoringDB
 
 
 def getMonitoringDB():
-    serverName = "Monitoring/Monitoring"
-    MonitoringDB = None
     try:
-        from DIRAC.MonitoringSystem.DB.MonitoringDB import MonitoringDB
+        if gMonitoringDB and gMonitoringDB._connected:
+            return gMonitoringDB
     except Exception:
         pass
-    return getDBOrClient(MonitoringDB, serverName)
+    return Client(url="Monitoring/Monitoring")

src/DIRAC/MonitoringSystem/DB/MonitoringDB.py

@@ -49,7 +49,6 @@ def __init__(self, name="Monitoring/MonitoringDB", readOnly=False):
         try:
             section = getDatabaseSection("Monitoring/MonitoringDB")
             indexPrefix = gConfig.getValue(f"{section}/IndexPrefix", CSGlobals.getSetup()).lower()
-
             # Connecting to the ES cluster
             super().__init__(dbname=name.split("/")[1], fullName=name, indexPrefix=indexPrefix)
         except RuntimeError as ex:
@@ -532,3 +531,9 @@ def getDataForAGivenPeriod(self, typeName, condDict, initialDate="", endDate="")
             condDict["endTime"] = calendar.timegm(time.gmtime()) * 1000
 
         return self.__getRawData(typeName, condDict)
+
+
+try:
+    gMonitoringDB = MonitoringDB()
+except:
+    gMonitoringDB = None