Store rung V151: collect each Availability Group's group_id and count groups by it (#4475)

Darling/Darling.Tests/AgGroupIdLiveReaderTests.cs

@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2026 Erik Darling, Darling Data LLC
+ *
+ * This file is part of the SQL Server Performance Monitor.
+ *
+ * Licensed under the MIT License. See LICENSE file in the project root for full license information.
+ */
+
+using System;
+using System.Threading.Tasks;
+using Npgsql;
+using PerformanceMonitor.Collectors;
+using PerformanceMonitor.Common;
+using PerformanceMonitor.Darling.Service.Mcp;
+using PerformanceMonitor.Darling.Storage;
+using PerformanceMonitor.Darling.Viewer;
+using Xunit;
+
+namespace Darling.Tests;
+
+/* #1776 own-store: this fact mints its own scratch database through ScratchPostgres and never touches another
+   test's rows, so it is deliberately NOT [Collection("live-postgres")]. */
+
+/// <summary>
+/// V151/#4475 live reader pin: two monitored SECONDARIES of one real Availability Group, its primary
+/// unmonitored, carrying the SAME <c>group_id</c> and DISJOINT replica-name sets, count as ONE group through
+/// the real reads -- the MCP/web AG reader's <c>distinct_ag_count</c> and the Viewer's <see cref="AgTopology"/>
+/// count over its own read -- not just through <see cref="AgTopology.CountDistinctGroups"/> called directly.
+/// </summary>
+public sealed class AgGroupIdLiveReaderTests
+{
+    private const string ServerNameA = "darling-ag-group-id-a";
+    private const string ServerNameB = "darling-ag-group-id-b";
+    private const string GroupId = "11111111-2222-3333-4444-555555555555";
+
+    private static string? BaseConnectionString => Environment.GetEnvironmentVariable("DARLING_TEST_PG");
+
+    [Fact]
+    public async Task DistinctAgCount_TwoSecondariesSameGroupId_DisjointReplicaSets_IsOneThroughTheRealReads()
+    {
+        var baseConnectionString = BaseConnectionString;
+        Assert.SkipWhen(string.IsNullOrEmpty(baseConnectionString), "Set DARLING_TEST_PG to run the live AG group_id reader pin.");
+
+        var ct = TestContext.Current.CancellationToken;
+        var scratch = await ScratchPostgres.CreateAsync(baseConnectionString!, ct);
+        var bodySucceeded = false;
+        try
+        {
+            await using var connection = new NpgsqlConnection(scratch.ConnectionString);
+            await connection.OpenAsync(ct);
+            await PgMigrations.MigrateAsync(connection, ct);
+
+            /* If the branch's V151 rung has not landed yet at the time this runs, plant the column ourselves
+               so this pin still compiles and runs against a store that predates it -- said explicitly rather
+               than silently swallowed. */
+            await using (var addColumn = new NpgsqlCommand(
+                "ALTER TABLE ag_replica_states ADD COLUMN IF NOT EXISTS group_id text;", connection))
+            {
+                await addColumn.ExecuteNonQueryAsync(ct);
+            }
+
+            var serverIdA = ServerIdHelper.GetDeterministicHashCode(ServerNameA);
+            var serverIdB = ServerIdHelper.GetDeterministicHashCode(ServerNameB);
+            await DarlingMcpTestData.RegisterServerAsync(connection, serverIdA, ServerNameA, ct);
+            await DarlingMcpTestData.RegisterServerAsync(connection, serverIdB, ServerNameB, ct);
+
+            var when = DarlingMcpTestData.TruncateToSeconds(DateTime.UtcNow).AddMinutes(-5);
+
+            /* Each server's replica-states row reports ONLY ITSELF -- the real shape a monitored SECONDARY
+               produces under sys.dm_hadr_availability_replica_states' local-only rule, with the AG's primary
+               unmonitored. The replica-name sets are DISJOINT ({AGNODE-A} vs {AGNODE-B}); only the shared
+               group_id links them. */
+            await DarlingMcpTestData.ExecAsync(connection, ct,
+                @"INSERT INTO ag_replica_states (collection_id, collection_time, server_id, server_name, ag_name, replica_server_name, role_desc, operational_state_desc, connected_state_desc, recovery_health_desc, synchronization_health_desc, availability_mode_desc, failover_mode_desc, endpoint_url, group_id)
+VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14,$15)",
+                CollectionIdGenerator.Next(), DarlingMcpTestData.Naive(when), serverIdA, ServerNameA, "AG1", "AGNODE-A", "SECONDARY",
+                "ONLINE", "CONNECTED", "ONLINE", "HEALTHY", "SYNCHRONOUS_COMMIT", "AUTOMATIC", "TCP://AGNODE-A:5022", GroupId);
+
+            await DarlingMcpTestData.ExecAsync(connection, ct,
+                @"INSERT INTO ag_replica_states (collection_id, collection_time, server_id, server_name, ag_name, replica_server_name, role_desc, operational_state_desc, connected_state_desc, recovery_health_desc, synchronization_health_desc, availability_mode_desc, failover_mode_desc, endpoint_url, group_id)
+VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14,$15)",
+                CollectionIdGenerator.Next(), DarlingMcpTestData.Naive(when), serverIdB, ServerNameB, "AG1", "AGNODE-B", "SECONDARY",
+                "ONLINE", "CONNECTED", "ONLINE", "HEALTHY", "SYNCHRONOUS_COMMIT", "AUTOMATIC", "TCP://AGNODE-B:5022", GroupId);
+
+            /* The MCP/web read (get_ag_health's distinct_ag_count), through DarlingAgReader.GetAgHealthAsync --
+               the same code path /api/ag and get_ag_health call, not AgTopology.CountDistinctGroups called
+               directly. */
+            await using var postgres = NpgsqlDataSource.Create(scratch.ConnectionString);
+            var mcpResult = await DarlingAgReader.GetAgHealthAsync(postgres, null, DateTime.UtcNow, cancellationToken: ct);
+            Assert.Equal(2, mcpResult.AvailabilityGroupCount);
+            Assert.Equal(1, mcpResult.DistinctAgCount);
+
+            /* The Viewer's own read and count, through ViewerDataService.GetAvailabilityGroupsAsync and
+               AgTopology.Counts over its cards -- the same call path the WPF AG tab uses, not a manual
+               reconstruction of its cards. */
+            var viewerService = new ViewerDataService(scratch.ConnectionString);
+            try
+            {
+                var cards = await viewerService.GetAvailabilityGroupsAsync(ct);
+                var (groups, reportingServers, views) = AgTopology.Counts(cards);
+
+                Assert.Equal(2, views);
+                Assert.Equal(2, reportingServers);
+                Assert.Equal(1, groups);
+            }
+            finally
+            {
+                await viewerService.DisposeAsync();
+            }
+
+            bodySucceeded = true;
+        }
+        finally
+        {
+            await LiveStoreCleanup.RunAsync(scratch.ConnectionString, bodySucceeded, async (_, _) => await Task.CompletedTask);
+            await scratch.DisposeAsync();
+        }
+    }
+}