Bug#33819386 Router queries similar data twice when refreshing the ClusterSet metadata.

In the current implementation when working with clusterset, some data is queried
twice while it could be fetched in a single query. That adds to the metadata refresh
execution time.

This patch optimizes the metadata query, merging separate queries into a single one.

Change-Id: I5dbad25d3b3f580de8899e033c33fea3c4fa6e70

Author: Andrzej Religa

router/src/harness/include/mysql/harness/event_state_tracker.h

@@ -52,7 +52,7 @@ class HARNESS_EXPORT EventStateTracker {
     MetadataNodeInGR,
     GRNodeInMetadata,
     TargetClusterPresentInOptions,
-    TargetClusterInvalidated,
+    ClusterInvalidatedInMetadata,
     ClusterWasBootstrappedAgainstClusterset,
     NoRightsToUpdateRouterAttributes
   };

router/src/metadata_cache/include/mysqlrouter/metadata_cache_datatypes.h

@@ -144,18 +144,25 @@ using metadata_servers_list_t = std::vector<metadata_server_t>;
  */
 class METADATA_CACHE_EXPORT ManagedCluster {
  public:
+  /** @brief UUID in the metadata */
+  std::string id;
+  /** @brief Name of the cluster */
+  std::string name;
   /** @brief List of the members that belong to the cluster */
   cluster_nodes_list_t members;
   /** @brief Whether the cluster is in single_primary_mode (from PFS in case of
    * GR) */
   bool single_primary_mode;
-  /** @brief Id of the view this metadata represents (only used for AR now)*/
-  uint64_t view_id{0};
   /** @brief Metadata for the cluster is not consistent (only applicable for
    * the GR cluster when the data in the GR metadata is not consistent with the
    * cluster metadata)*/
   bool md_discrepancy{false};
 
+  /** @brief Is this a PRIMARY Cluster in case of ClusterSet */
+  bool is_primary{true};
+  /** @brief Is the Cluster marked as invalid in the metadata */
+  bool is_invalidated{false};
+
   // address of the writable metadata server that can be used for updating the
   // metadata (router version, last_check_in), error code if not found
   stdx::expected<metadata_cache::metadata_server_t, std::error_code>
@@ -173,6 +180,10 @@ class METADATA_CACHE_EXPORT ManagedCluster {
 struct METADATA_CACHE_EXPORT ClusterTopology {
   ManagedCluster cluster_data;
   metadata_servers_list_t metadata_servers;
+
+  /** @brief Id of the view this metadata represents (used for AR and
+   * ClusterSets)*/
+  uint64_t view_id{0};
 };
 
 /**

router/src/metadata_cache/src/cluster_metadata_ar.cc

@@ -1,5 +1,5 @@
 /*
-  Copyright (c) 2019, 2021, Oracle and/or its affiliates.
+  Copyright (c) 2019, 2022, Oracle and/or its affiliates.
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
@@ -118,7 +118,7 @@ ARClusterMetadata::fetch_cluster_topology(
   result.cluster_data.members = std::move(new_instances);
   result.cluster_data.writable_server =
       find_rw_server(result.cluster_data.members);
-  result.cluster_data.view_id = this->view_id_;
+  result.view_id = this->view_id_;
 
   // for ReplicaSet Cluster we assume metadata servers are just Cluster nodes
   for (const auto &cluster_node : result.cluster_data.members) {