This commit provides additional functionality that is logically relat…

…ed to the

earlier commit 923982c

Original commit message:

ENG-1333. Report errors in LoadBalancer.

Summary: Added more logging, added Result and Status to load balancer flow and bubble up error messages to RunLoadBalancer.

Test Plan: ybd --cxx_test catalog_manager-test_ent --gtest_filter TestLoadBalancerEnterprise.TestLoadBalancerAlgorithm

Reviewers: bogdan, bharat

Reviewed By: bharat

Subscribers: ybase

Differential Revision: https://phabricator.dev.yugabyte.com/D5647

ent/src/yb/master/cluster_balance.cc

@@ -11,15 +11,15 @@ namespace enterprise {
 
 Result<bool> ClusterLoadBalancer::HandleLeaderMoves(
     TabletId* out_tablet_id, TabletServerId* out_from_ts, TabletServerId* out_to_ts) {
-  if (HandleLeaderLoadIfNonAffinitized(out_tablet_id, out_from_ts, out_to_ts)) {
+  if (VERIFY_RESULT(HandleLeaderLoadIfNonAffinitized(out_tablet_id, out_from_ts, out_to_ts))) {
     RETURN_NOT_OK(MoveLeader(*out_tablet_id, *out_from_ts, *out_to_ts));
     return true;
   }
 
   return super::HandleLeaderMoves(out_tablet_id, out_from_ts, out_to_ts);
 }
 
-Result<bool> ClusterLoadBalancer::AnalyzeTablets(const TableId& table_uuid) {
+Status ClusterLoadBalancer::AnalyzeTablets(const TableId& table_uuid) {
   ClusterLoadState* ent_state = GetEntState();
   GetAllAffinitizedZones(&ent_state->affinitized_zones_);
   return super::AnalyzeTablets(table_uuid);
@@ -35,7 +35,7 @@ void ClusterLoadBalancer::GetAllAffinitizedZones(AffinitizedZonesSet* affinitize
   }
 }
 
-bool ClusterLoadBalancer::HandleLeaderLoadIfNonAffinitized(TabletId* moving_tablet_id,
+Result<bool> ClusterLoadBalancer::HandleLeaderLoadIfNonAffinitized(TabletId* moving_tablet_id,
                                                            TabletServerId* from_ts,
                                                            TabletServerId* to_ts) {
   // Similar to normal leader balancing, we double iterate from most loaded to least loaded
@@ -91,7 +91,7 @@ void ClusterLoadBalancer::PopulatePlacementInfo(TabletInfo* tablet, PlacementInf
   }
 }
 
-bool ClusterLoadBalancer::UpdateTabletInfo(TabletInfo* tablet) {
+Status ClusterLoadBalancer::UpdateTabletInfo(TabletInfo* tablet) {
   const auto& table_id = tablet->table()->id();
   // Set the placement information on a per-table basis, only once.
   if (!state_->placement_by_table_.count(table_id)) {

ent/src/yb/master/cluster_balance.h

@@ -19,18 +19,18 @@ class ClusterLoadBalancer : public yb::master::ClusterLoadBalancer {
   Result<bool> HandleLeaderMoves(
       TabletId* out_tablet_id, TabletServerId* out_from_ts, TabletServerId* out_to_ts) override;
 
-  Result<bool> AnalyzeTablets(const TableId& table_uuid) override;
+  CHECKED_STATUS AnalyzeTablets(const TableId& table_uuid) override;
 
   virtual void GetAllAffinitizedZones(AffinitizedZonesSet* affinitized_zones) const;
 
   // This function handles leader load from non-affinitized to affinitized nodes.
   // If it can find a way to move leader load from a non-affinitized to affinitized node,
-  // returns true. Otherwise, returns false.
+  // returns true, if not returns false, if error is found, returns Status.
   // This is called before normal leader load balancing.
-  bool HandleLeaderLoadIfNonAffinitized(
+  Result<bool> HandleLeaderLoadIfNonAffinitized(
       TabletId* moving_tablet_id, TabletServerId* from_ts, TabletServerId* to_ts);
 
-  bool UpdateTabletInfo(TabletInfo* tablet) override;
+  CHECKED_STATUS UpdateTabletInfo(TabletInfo* tablet) override;
 
   // Runs the load balancer once for the live and all read only clusters, in order
   // of the cluster config.