Tuning constraints

Signed-off-by: Arpit Bandejiya <abandeji@amazon.com>

Author: alchemist51

server/src/main/java/org/opensearch/cluster/routing/allocation/ConstraintTypes.java

@@ -91,7 +91,7 @@ public static Predicate<Constraint.ConstraintParams> isPrimaryShardsPerNodeBreac
         return (params) -> {
             int primaryShardCount = params.getNode().numPrimaryShards();
             int allowedPrimaryShardCount = (int) Math.ceil(params.getBalancer().avgPrimaryShardsPerNode() * (1 + buffer));
-            return primaryShardCount >= allowedPrimaryShardCount;
+            return primaryShardCount > allowedPrimaryShardCount;
         };
     }
 }

server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/BalancedShardsAllocator.java

@@ -169,6 +169,9 @@ public BalancedShardsAllocator(Settings settings) {
 
     @Inject
     public BalancedShardsAllocator(Settings settings, ClusterSettings clusterSettings) {
+        setIndexBalanceFactor(INDEX_BALANCE_FACTOR_SETTING.get(settings));
+        setShardBalanceFactor(SHARD_BALANCE_FACTOR_SETTING.get(settings));
+        setPreferPrimaryShardBalanceBuffer(PREFER_PRIMARY_SHARD_BALANCE_BUFFER.get(settings));
         setWeightFunction(
             INDEX_BALANCE_FACTOR_SETTING.get(settings),
             SHARD_BALANCE_FACTOR_SETTING.get(settings),
@@ -177,7 +180,6 @@ public BalancedShardsAllocator(Settings settings, ClusterSettings clusterSetting
         setThreshold(THRESHOLD_SETTING.get(settings));
         setPreferPrimaryShardBalance(PREFER_PRIMARY_SHARD_BALANCE.get(settings));
         setShardMovementStrategy(SHARD_MOVEMENT_STRATEGY_SETTING.get(settings));
-        setPreferPrimaryShardBalanceBuffer(PREFER_PRIMARY_SHARD_BALANCE_BUFFER.get(settings));
         clusterSettings.addSettingsUpdateConsumer(PREFER_PRIMARY_SHARD_BALANCE, this::setPreferPrimaryShardBalance);
         clusterSettings.addSettingsUpdateConsumer(SHARD_MOVE_PRIMARY_FIRST_SETTING, this::setMovePrimaryFirst);
         clusterSettings.addSettingsUpdateConsumer(SHARD_MOVEMENT_STRATEGY_SETTING, this::setShardMovementStrategy);

server/src/main/java/org/opensearch/cluster/routing/allocation/allocator/LocalShardsBalancer.java

@@ -998,7 +998,7 @@ private boolean tryRelocateShard(BalancedShardsAllocator.ModelNode minNode, Bala
                 // doing such relocation wouldn't help in primary balance.
                 if (preferPrimaryBalance == true
                     && shard.primary()
-                    && maxNode.numPrimaryShards(shard.getIndexName()) - minNode.numPrimaryShards(shard.getIndexName()) < 2) {
+                    && maxNode.numPrimaryShards() - minNode.numPrimaryShards() < 2) {
                     continue;
                 }
 

server/src/main/java/org/opensearch/common/settings/ClusterSettings.java

@@ -248,6 +248,7 @@ public void apply(Settings value, Settings current, Settings previous) {
                 AwarenessReplicaBalance.CLUSTER_ROUTING_ALLOCATION_AWARENESS_BALANCE_SETTING,
                 BalancedShardsAllocator.INDEX_BALANCE_FACTOR_SETTING,
                 BalancedShardsAllocator.SHARD_BALANCE_FACTOR_SETTING,
+                BalancedShardsAllocator.PREFER_PRIMARY_SHARD_BALANCE_BUFFER,
                 BalancedShardsAllocator.PREFER_PRIMARY_SHARD_BALANCE,
                 BalancedShardsAllocator.SHARD_MOVE_PRIMARY_FIRST_SETTING,
                 BalancedShardsAllocator.SHARD_MOVEMENT_STRATEGY_SETTING,