MB-52109 planner - tenant aware rebalance

Implement sub-cluster/tenant affinity aware planner which moves tenants
from nodes above HWM usage threshold to nodes below LWM usage threshold.

The core algorithm works as follows:
1. Identify the nodes above HWM usage threshold.
2. Identify the candidate tenants to move out such that resource usage comes
   below LWM threshold after the rebalance.
3. Identify the target nodes below LWM usage threshold.
4. Place the candidate tenants on target nodes upto LWM usage
   threshold.

The following cases will be addressed in future commits:
1. Replica repair
2. Moving indexes from ejected nodes/swap rebalance.

Change-Id: I0ff1fed18b764595b6907f461b86bc11c2424ad2

secondary/common/config.go

@@ -3311,6 +3311,14 @@ var SystemConfig = Config{
 		false, // case-insensitive
 	},
 
+	"indexer.settings.units_quota": ConfigValue{
+		uint64(5000 * 20),
+		"Maximum RU/WU quota for indexer",
+		uint64(5000 * 20),
+		false, // mutable
+		false, // case-insensitive
+	},
+
 	"indexer.settings.serverless.indexLimit": ConfigValue{
 		200,
 		"Limit on the number of indexes that can be created per bucket in Serverless Mode.",

secondary/indexer/rebalancer.go

@@ -386,9 +386,15 @@ func (r *Rebalancer) initRebalAsync() {
 					}
 
 					start := time.Now()
-					r.transferTokens, hostToIndexToRemove, err = planner.ExecuteRebalance(cfg["clusterAddr"].String(), *r.topologyChange,
-						r.nodeUUID, onEjectOnly, disableReplicaRepair, threshold, timeout, cpuProfile,
-						minIterPerTemp, maxIterPerTemp)
+
+					if c.IsServerlessDeployment() {
+						r.transferTokens, hostToIndexToRemove, err = planner.ExecuteTenantAwareRebalance(cfg["clusterAddr"].String(),
+							*r.topologyChange, r.nodeUUID)
+					} else {
+						r.transferTokens, hostToIndexToRemove, err = planner.ExecuteRebalance(cfg["clusterAddr"].String(), *r.topologyChange,
+							r.nodeUUID, onEjectOnly, disableReplicaRepair, threshold, timeout, cpuProfile,
+							minIterPerTemp, maxIterPerTemp)
+					}
 					if err != nil {
 						l.Errorf("Rebalancer::initRebalAsync Planner Error %v", err)
 						go r.finishRebalance(err)

secondary/indexer/stats_manager.go

@@ -832,6 +832,7 @@ func (s *IndexerStats) SetPlannerFilters() {
 	s.memoryUsedStorage.AddFilter(stats.PlannerFilter)
 	s.memoryUsed.AddFilter(stats.PlannerFilter)
 	s.memoryQuota.AddFilter(stats.PlannerFilter)
+	s.memoryRss.AddFilter(stats.PlannerFilter)
 	s.uptime.AddFilter(stats.PlannerFilter)
 	s.cpuUtilization.AddFilter(stats.PlannerFilter)
 }