Implement Known Endpoints persistence with EF Core insert-only tables

src/Directory.Packages.props

@@ -12,6 +12,7 @@
     <PackageVersion Include="ByteSize" Version="2.1.2" />
     <PackageVersion Include="Caliburn.Micro" Version="5.0.258" />
     <PackageVersion Include="DnsClient" Version="1.8.0" />
+    <PackageVersion Include="EFCore.NamingConventions" Version="10.0.1" />
     <PackageVersion Include="FluentValidation" Version="12.1.1" />
     <PackageVersion Include="Fody" Version="6.9.3" />
     <PackageVersion Include="GitHubActionsTestLogger" Version="3.0.4" />

src/ServiceControl.Persistence.EFCore.PostgreSql/Infrastructure/KnownEndpointsReconciler.cs

@@ -0,0 +1,46 @@
+namespace ServiceControl.Persistence.EFCore.PostgreSql.Infrastructure;
+
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using ServiceControl.Persistence.EFCore.DbContexts;
+using ServiceControl.Persistence.EFCore.Infrastructure;
+
+class KnownEndpointsReconciler(
+    ILogger<KnownEndpointsReconciler> logger,
+    TimeProvider timeProvider,
+    IServiceScopeFactory serviceScopeFactory)
+    : InsertOnlyTableReconciler(
+        logger, timeProvider, serviceScopeFactory, nameof(KnownEndpointsReconciler))
+{
+    protected override Task<int> ReconcileBatch(ServiceControlDbContext dbContext, CancellationToken stoppingToken) =>
+        ReconcileBatch(dbContext, BatchSize, stoppingToken);
+
+    // Static so tests can execute a batch deterministically without the background service's timer loop.
+    // Must be called within an active transaction because of the pg_try_advisory_xact_lock.
+    internal static async Task<int> ReconcileBatch(ServiceControlDbContext dbContext, int batchSize, CancellationToken cancellationToken)
+    {
+        var sql = """
+            WITH lock_check AS (
+                SELECT pg_try_advisory_xact_lock(hashtext('known_endpoints_sync')) AS acquired
+            ),
+            batch AS (
+                SELECT ctid FROM "known_endpoints_insert_only"
+                WHERE (SELECT acquired FROM lock_check)
+                LIMIT @batchSize
+            ),
+            ins AS (
+                INSERT INTO "known_endpoints" ("id", "name", "host_id", "host", "monitored")
+                SELECT DISTINCT ON ("known_endpoint_id") "known_endpoint_id", "name", "host_id", "host", FALSE
+                FROM "known_endpoints_insert_only"
+                WHERE ctid IN (SELECT ctid FROM batch)
+                ON CONFLICT ("id") DO NOTHING
+            )
+            DELETE FROM "known_endpoints_insert_only"
+            WHERE ctid IN (SELECT ctid FROM batch);
+            """;
+
+        var rowsAffected = await dbContext.Database.ExecuteSqlRawAsync(sql, [new Npgsql.NpgsqlParameter("@batchSize", batchSize)], cancellationToken);
+        return rowsAffected;
+    }
+}

src/ServiceControl.Persistence.EFCore.PostgreSql/Migrations/20260720230745_Initial.cs

@@ -0,0 +1,62 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace ServiceControl.Persistence.EFCore.PostgreSql.Migrations
+{
+    /// <inheritdoc />
+    public partial class Initial : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "known_endpoints",
+                columns: table => new
+                {
+                    id = table.Column<Guid>(type: "uuid", nullable: false),
+                    name = table.Column<string>(type: "text", nullable: false),
+                    host_id = table.Column<Guid>(type: "uuid", nullable: false),
+                    host = table.Column<string>(type: "text", nullable: false),
+                    monitored = table.Column<bool>(type: "boolean", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_known_endpoints", x => x.id);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "known_endpoints_insert_only",
+                columns: table => new
+                {
+                    id = table.Column<long>(type: "bigint", nullable: false)
+                        .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn),
+                    known_endpoint_id = table.Column<Guid>(type: "uuid", nullable: false),
+                    name = table.Column<string>(type: "text", nullable: false),
+                    host_id = table.Column<Guid>(type: "uuid", nullable: false),
+                    host = table.Column<string>(type: "text", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_known_endpoints_insert_only", x => x.id);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_known_endpoints_insert_only_known_endpoint_id",
+                table: "known_endpoints_insert_only",
+                column: "known_endpoint_id");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "known_endpoints");
+
+            migrationBuilder.DropTable(
+                name: "known_endpoints_insert_only");
+        }
+    }
+}

src/ServiceControl.Persistence.EFCore.PostgreSql/Migrations/PostgreSqlServiceControlDbContextModelSnapshot.cs

@@ -0,0 +1,90 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+using ServiceControl.Persistence.EFCore.PostgreSql;
+
+#nullable disable
+
+namespace ServiceControl.Persistence.EFCore.PostgreSql.Migrations
+{
+    [DbContext(typeof(PostgreSqlServiceControlDbContext))]
+    partial class PostgreSqlServiceControlDbContextModelSnapshot : ModelSnapshot
+    {
+        protected override void BuildModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "10.0.9")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("ServiceControl.Persistence.EFCore.Entities.KnownEndpointEntity", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .HasColumnType("uuid")
+                        .HasColumnName("id");
+
+                    b.Property<string>("Host")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("host");
+
+                    b.Property<Guid>("HostId")
+                        .HasColumnType("uuid")
+                        .HasColumnName("host_id");
+
+                    b.Property<bool>("Monitored")
+                        .HasColumnType("boolean")
+                        .HasColumnName("monitored");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("name");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("known_endpoints", (string)null);
+                });
+
+            modelBuilder.Entity("ServiceControl.Persistence.EFCore.Entities.KnownEndpointInsertOnlyEntity", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<string>("Host")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("host");
+
+                    b.Property<Guid>("HostId")
+                        .HasColumnType("uuid")
+                        .HasColumnName("host_id");
+
+                    b.Property<Guid>("KnownEndpointId")
+                        .HasColumnType("uuid")
+                        .HasColumnName("known_endpoint_id");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("name");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("KnownEndpointId");
+
+                    b.ToTable("known_endpoints_insert_only", (string)null);
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

src/ServiceControl.Persistence.EFCore.PostgreSql/PostgreSqlPersistence.cs

@@ -4,6 +4,7 @@ namespace ServiceControl.Persistence.EFCore.PostgreSql;
 using Microsoft.Extensions.DependencyInjection;
 using ServiceControl.Persistence.EFCore.Abstractions;
 using ServiceControl.Persistence.EFCore.DbContexts;
+using ServiceControl.Persistence.EFCore.PostgreSql.Infrastructure;
 
 class PostgreSqlPersistence(PostgreSqlPersisterSettings settings) : BasePersistence, IPersistence
 {
@@ -12,6 +13,8 @@ public void AddPersistence(IServiceCollection services)
         RegisterSettings(services);
         ConfigureDbContext(services);
         RegisterDataStores(services);
+
+        services.AddHostedService<KnownEndpointsReconciler>();
     }
 
     public void AddInstaller(IServiceCollection services)

src/ServiceControl.Persistence.EFCore.PostgreSql/PostgreSqlServiceControlDbContext.cs

@@ -5,4 +5,11 @@ namespace ServiceControl.Persistence.EFCore.PostgreSql;
 
 public class PostgreSqlServiceControlDbContext(DbContextOptions<PostgreSqlServiceControlDbContext> options) : ServiceControlDbContext(options)
 {
+    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
+    {
+        base.OnConfiguring(optionsBuilder);
+
+        // Use snake_case naming convention for PostgreSQL
+        optionsBuilder.UseSnakeCaseNamingConvention();
+    }
 }

src/ServiceControl.Persistence.EFCore.PostgreSql/ServiceControl.Persistence.EFCore.PostgreSql.csproj

@@ -8,20 +8,29 @@
     <DisableTransitiveProjectReferences>true</DisableTransitiveProjectReferences>
   </PropertyGroup>
 
-  <ItemGroup>
-    <!-- Private=false & ExcludeAssets=runtime prevent repeatedly including binary dependencies of ServiceControl.Persistence and its dependencies in each persister directory -->
+  <ItemGroup Condition="'$(Configuration)' == 'Release'">
+    <!-- Private=false & ExcludeAssets=runtime prevent repeatedly including binary dependencies of ServiceControl.Persistence
+         and its dependencies in each persister directory. Release-only: the host loads these via PluginAssemblyLoadContext,
+         which falls back to the host's own copy. Debug needs them copied locally for dotnet-ef design-time tooling. -->
     <ProjectReference Include="../ServiceControl.Configuration/ServiceControl.Configuration.csproj" Private="false" ExcludeAssets="runtime" />
     <ProjectReference Include="../ServiceControl.Infrastructure/ServiceControl.Infrastructure.csproj" Private="false" ExcludeAssets="runtime" />
     <ProjectReference Include="../ServiceControl.Persistence/ServiceControl.Persistence.csproj" Private="false" ExcludeAssets="runtime" />
   </ItemGroup>
 
+  <ItemGroup Condition="'$(Configuration)' != 'Release'">
+    <ProjectReference Include="../ServiceControl.Configuration/ServiceControl.Configuration.csproj" />
+    <ProjectReference Include="../ServiceControl.Infrastructure/ServiceControl.Infrastructure.csproj" />
+    <ProjectReference Include="../ServiceControl.Persistence/ServiceControl.Persistence.csproj" />
+  </ItemGroup>
+
   <ItemGroup>
     <!-- Not Private=false or ExcludeAssets because the shared EF Core assembly ships inside this persister's folder -->
     <ProjectReference Include="../ServiceControl.Persistence.EFCore/ServiceControl.Persistence.EFCore.csproj" />
   </ItemGroup>
 
   <ItemGroup>
     <!-- Design-time only, for dotnet-ef tooling. Debug-only so it (and its Roslyn dependency tail) stays out of the shipped Release artifact -->
+    <PackageReference Include="EFCore.NamingConventions" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Design" PrivateAssets="all" Condition="'$(Configuration)' == 'Debug'" />
     <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" />
   </ItemGroup>