[DB-11813] Rename ysql_conn_mgr_idle_or_pending_clients metric name

Summary:
We were using the stat name **idle_or_pending_clients** which is not accurate. This stat name is misleading and hence we are moving to a different name for this stat. The new name is **waiting_clients**.

The PR makes the name change and also the changes needed for where the stat is being used.

The definition of the stat is as below

```
Number of logical connections which are either idle (i.e. no ongoing transaction) or waiting for the worker thread to be processed (i.e. waiting for od_router_attach to be called).
```
The above definition has not changed and is same as the old one.

Test Plan:
  - Hit the 13000/connections endpoint and verified that the stats are shown in accordance with the new name as **waiting_logical_connections**

  - Hit the 13000/prometheus-metrics endpoint and verified that the metrics are published in accordance the new name as **ysql_conn_mgr_waiting_clients**

Jenkins: all tests, enable connection manager

Reviewers: mkumar, rbarigidad, skumar, asrinivasan, nkumar, djiang

Reviewed By: rbarigidad, djiang

Subscribers: ybase, yql

Differential Revision: https://phorge.dev.yugabyte.com/D35992

java/yb-ysql-conn-mgr/src/test/java/org/yb/ysqlconnmgr/TestStatsAndMetrics.java

@@ -27,7 +27,7 @@ public class TestStatsAndMetrics extends BaseYsqlConnMgr {
        "user_name",
        "active_logical_connections",
        "queued_logical_connections",
-       "idle_or_pending_logical_connections",
+       "waiting_logical_connections",
        "active_physical_connections",
        "idle_physical_connections",
        "avg_wait_time_ns",
@@ -117,7 +117,7 @@ private void testNumLogicalConnections(String db_name,
     int num_logical_conn =
     pool.get("active_logical_connections").getAsInt() +
     pool.get("queued_logical_connections").getAsInt() +
-    pool.get("idle_or_pending_logical_connections").getAsInt();
+    pool.get("waiting_logical_connections").getAsInt();
     assertEquals("Did not get the expected number of logical connections for pool with user "
         + user_name + " and database " + db_name, exp_val, num_logical_conn);
   }

src/odyssey/sources/cron.c

@@ -80,7 +80,7 @@ static int od_cron_stat_cb(od_route_t *route, od_stat_t *current,
 			route->client_pool.count_active;
 		instance->yb_stats[index].queued_clients =
 			route->client_pool.count_queue;
-		instance->yb_stats[index].idle_or_pending_clients =
+		instance->yb_stats[index].waiting_clients =
 			route->client_pool.count_pending;
 		instance->yb_stats[index].active_servers =
 			route->server_pool.count_active;

src/postgres/src/backend/utils/misc/yb_ysql_conn_mgr_helper.c

@@ -887,7 +887,7 @@ YbGetNumYsqlConnMgrConnections(const char *db_name, const char *user_name,
 		 * can get changed while reading the shared memory segment.
 		 */
 		*num_logical_conn += shmp[itr].active_clients +
-							 shmp[itr].idle_or_pending_clients +
+							 shmp[itr].waiting_clients +
 							 shmp[itr].queued_clients;
 		*num_physical_conn += shmp[itr].active_servers + shmp[itr].idle_servers;
 	}

src/yb/tserver/metrics_snapshotter.cc

@@ -377,7 +377,7 @@ Status MetricsSnapshotter::Thread::DoYsqlConnMgrMetricsSnapshot(const client::Ta
     if (strcmp(stat.database_name, "control_connection") != 0) {
       total_logical_connections += stat.active_clients +
                                    stat.queued_clients +
-                                   stat.idle_or_pending_clients;
+                                   stat.waiting_clients;
       total_physical_connections += stat.active_servers + stat.idle_servers;
     }
   }

src/yb/yql/pggate/webserver/pgsql_webserver_wrapper.cc

@@ -202,8 +202,8 @@ void emitYsqlConnectionManagerMetrics(PrometheusWriter *pwriter) {
   for (ConnectionStats stats : stats_list) {
     ysql_conn_mgr_metrics.push_back({"ysql_conn_mgr_active_clients", stats.active_clients});
     ysql_conn_mgr_metrics.push_back({"ysql_conn_mgr_queued_clients", stats.queued_clients});
-    ysql_conn_mgr_metrics.push_back({"ysql_conn_mgr_idle_or_pending_clients",
-            stats.idle_or_pending_clients});
+    ysql_conn_mgr_metrics.push_back({"ysql_conn_mgr_waiting_clients",
+            stats.waiting_clients});
     ysql_conn_mgr_metrics.push_back({"ysql_conn_mgr_active_servers", stats.active_servers});
     ysql_conn_mgr_metrics.push_back({"ysql_conn_mgr_idle_servers", stats.idle_servers});
     ysql_conn_mgr_metrics.push_back({"ysql_conn_mgr_query_rate", stats.query_rate});
@@ -478,8 +478,8 @@ static void PgLogicalRpczHandler(const Webserver::WebRequest &req, Webserver::We
 
     // Number of logical connections which are either idle (i.e. no ongoing transaction) or waiting
     // for the worker thread to be processed (i.e. waiting for od_router_attach to be called).
-    writer.String("idle_or_pending_logical_connections");
-    writer.Int64(stat.idle_or_pending_clients);
+    writer.String("waiting_logical_connections");
+    writer.Int64(stat.waiting_clients);
 
     // Number of physical connections which currently attached to a logical connection.
     writer.String("active_physical_connections");

src/yb/yql/ysql_conn_mgr_wrapper/ysql_conn_mgr_stats.h

@@ -29,7 +29,7 @@
 struct ConnectionStats {
   uint64_t active_clients;
   uint64_t queued_clients;
-  uint64_t idle_or_pending_clients;
+  uint64_t waiting_clients;
   uint64_t active_servers;
   uint64_t idle_servers;
   uint64_t query_rate;

yugabyted-ui/apiserver/cmd/server/.docs/api/openapi.yaml

@@ -2615,7 +2615,7 @@ components:
         queued_logical_connections:
           format: int64
           type: integer
-        idle_or_pending_logical_connections:
+        waiting_logical_connections:
           format: int64
           type: integer
         active_physical_connections:
@@ -2637,7 +2637,7 @@ components:
       - active_logical_connections
       - active_physical_connections
       - avg_wait_time_ns
-      - idle_or_pending_logical_connections
+      - waiting_logical_connections
       - idle_physical_connections
       - qps
       - queued_logical_connections

yugabyted-ui/apiserver/cmd/server/handlers/api_cluster_info.go

@@ -1722,8 +1722,7 @@ func (c *Container) GetClusterConnections(ctx echo.Context) error {
                         UserName: connectionPool.UserName,
                         ActiveLogicalConnections: connectionPool.ActiveLogicalConnections,
                         QueuedLogicalConnections: connectionPool.QueuedLogicalConnections,
-                        IdleOrPendingLogicalConnections:
-                            connectionPool.IdleOrPendingLogicalConnections,
+                        WaitingLogicalConnections: connectionPool.WaitingLogicalConnections,
                         ActivePhysicalConnections: connectionPool.ActivePhysicalConnections,
                         IdlePhysicalConnections: connectionPool.IdlePhysicalConnections,
                         AvgWaitTimeNs: connectionPool.AvgWaitTimeNs,

yugabyted-ui/apiserver/cmd/server/helpers/connections_http_request.go

@@ -13,7 +13,7 @@ type ConnectionPool struct {
     UserName                        string `json:"user_name"`
     ActiveLogicalConnections        int64  `json:"active_logical_connections"`
     QueuedLogicalConnections        int64  `json:"queued_logical_connections"`
-    IdleOrPendingLogicalConnections int64  `json:"idle_or_pending_logical_connections"`
+    WaitingLogicalConnections       int64  `json:"waiting_logical_connections"`
     ActivePhysicalConnections       int64  `json:"active_physical_connections"`
     IdlePhysicalConnections         int64  `json:"idle_physical_connections"`
     AvgWaitTimeNs                   int64  `json:"avg_wait_time_ns"`

yugabyted-ui/apiserver/cmd/server/models/model_connection_stats_item.go

@@ -10,7 +10,7 @@ type ConnectionStatsItem struct {
 
     QueuedLogicalConnections int64 `json:"queued_logical_connections"`
 
-    IdleOrPendingLogicalConnections int64 `json:"idle_or_pending_logical_connections"`
+    WaitingLogicalConnections int64 `json:"waiting_logical_connections"`
 
     ActivePhysicalConnections int64 `json:"active_physical_connections"`
 

yugabyted-ui/apiserver/conf/openapi.yml

@@ -1570,7 +1570,7 @@ components:
         queued_logical_connections:
           type: integer
           format: int64
-        idle_or_pending_logical_connections:
+        waiting_logical_connections:
           type: integer
           format: int64
         active_physical_connections:
@@ -1591,7 +1591,7 @@ components:
       required:
         - active_logical_connections
         - queued_logical_connections
-        - idle_or_pending_logical_connections
+        - waiting_logical_connections
         - active_physical_connections
         - idle_physical_connections
         - avg_wait_time_ns

yugabyted-ui/apiserver/conf/openapi/schemas/_index.yaml

@@ -1176,7 +1176,7 @@ ConnectionStatsItem:
     queued_logical_connections:
       type: integer
       format: int64
-    idle_or_pending_logical_connections:
+    waiting_logical_connections:
       type: integer
       format: int64
     active_physical_connections:
@@ -1197,7 +1197,7 @@ ConnectionStatsItem:
   required:
     - active_logical_connections
     - queued_logical_connections
-    - idle_or_pending_logical_connections
+    - waiting_logical_connections
     - active_physical_connections
     - idle_physical_connections
     - avg_wait_time_ns

yugabyted-ui/ui/src/api/src/models/ConnectionStats.ts

@@ -37,7 +37,7 @@ export interface ConnectionStats  {
    * @type {number}
    * @memberof ConnectionStats
    */
-  idle_or_pending_logical_connections: number;
+  waiting_logical_connections: number;
   /**
    * 
    * @type {number}

yugabyted-ui/ui/src/api/src/models/ConnectionStatsItem.ts

@@ -49,7 +49,7 @@ export interface ConnectionStatsItem  {
    * @type {number}
    * @memberof ConnectionStatsItem
    */
-  idle_or_pending_logical_connections: number;
+  waiting_logical_connections: number;
   /**
    * 
    * @type {number}