Fixes #15041: The computation of changes by rules, at start of web interface, is quite slow

webapp/sources/rudder/rudder-core/src/main/scala/com/normation/rudder/repository/ReportsRepository.scala

@@ -109,6 +109,7 @@ trait ReportsRepository {
   //return the reports between the two ids, limited to limit number of reports, in asc order of id.
   def getReportsByKindBeetween(lower: Long, upper: Long, limit: Int, kinds: List[String]) : Box[Seq[(Long, Reports)]]
 
+  def countChangeReportsByBatch(intervals : List[Interval]) : Box[Map[RuleId, Map[Interval, Int]]]
 
   //nodechangesServices
   /*

webapp/sources/rudder/rudder-core/src/main/scala/com/normation/rudder/repository/jdbc/ReportsJdbcRepository.scala

@@ -391,6 +391,31 @@ class ReportsJdbcRepository(doobie: Doobie) extends ReportsRepository with Logga
     }).transact(xa).attempt.unsafeRunSync ?~! s"Could not fetch the last completed runs from database."
   }
 
+  /**
+    * returns the changes between startTime and now, using intervalInHour interval size
+    */
+
+  override def countChangeReportsByBatch(intervals : List[Interval]) : Box[Map[RuleId, Map[Interval, Int]]] = {
+    import com.normation.utils.Control.sequence
+    logger.debug(s"Fetching all changes for intervals ${intervals.mkString(",")}")
+    val beginTime = System.currentTimeMillis()
+    val rules: Box[Seq[Vector[(RuleId, Interval, Int)]]] = sequence(intervals) { interval =>
+      (query[(RuleId, Int)](
+        s"""select ruleid, count(*) as number
+          from ruddersysevents
+          where eventtype = 'result_repaired' and executionTimeStamp > '${new Timestamp(interval.getStartMillis)}' and executionTimeStamp <= '${new Timestamp(interval.getEndMillis)}'
+          group by ruleid;
+      """
+      ).to[Vector].transact(xa).attempt.unsafeRunSync ?~! s"Error when trying to retrieve change reports on interval ${interval.toString}").map { res =>
+
+        res.map { case (ruleid, count) => (ruleid, interval, count) }
+      }
+    }
+    val  endQuery = System.currentTimeMillis()
+    logger.debug(s"Fetched all changes in intervals in ${(endQuery - beginTime)} ms")
+    rules.map(x => x.flatten.groupBy(_._1).mapValues( _.groupBy(_._2).mapValues(_.map ( _._3).head)))  //head non empty due to groupBy, and seq == 1 by query
+  }
+
   override def countChangeReports(startTime: DateTime, intervalInHour: Int): Box[Map[RuleId, Map[Interval, Int]]] = {
     //special mapper to retrieve correct interval. It is dependant of starttime / intervalInHour
     implicit val intervalMeta: Meta[Interval] = Meta[Int].xmap(
@@ -404,6 +429,9 @@ class ReportsJdbcRepository(doobie: Doobie) extends ReportsRepository with Logga
     //be careful, extract from 'epoch' gives seconds, not millis
     val mod = intervalInHour * 3600
     val start = startTime.getMillis / 1000
+
+
+
     ((query[(RuleId, Int, Interval)](
       s"""select ruleid, count(*) as number, ( extract('epoch' from executiontimestamp)::bigint - ${start})/${mod} as interval
           from ruddersysevents

webapp/sources/rudder/rudder-core/src/main/scala/com/normation/rudder/services/reports/NodeChangesService.scala

@@ -144,11 +144,15 @@ class NodeChangesServiceImpl(
    * regroup them by rule, and by interval of 6 hours.
    */
   override def countChangesByRuleByInterval(): Box[ChangesByRule] = {
-    val start = getCurrentValidIntervals(None).map(_.getStart).minBy(_.getMillis)
+    logger.debug(s"Get all changes on all rules")
+    val beginTime = System.currentTimeMillis()
+    val intervals = getCurrentValidIntervals(None)
     // Regroup changes by interval
     for {
-      changes <- reportsRepository.countChangeReports(start, 6)
+      changes <- reportsRepository.countChangeReportsByBatch(intervals)
     } yield {
+      val endTime = System.currentTimeMillis()
+      logger.debug(s"Fetched all changes for all rules in ${(endTime - beginTime)} ms")
       changes
     }
   }