fix(csharp): emit bare hostname for telemetry host_url to match JDBC

csharp/doc/telemetry-design.md

@@ -1793,7 +1793,7 @@ The JDBC driver uses Jackson with explicit `@JsonProperty("session_id")` annotat
   "session_id": "abc123",
   "sql_statement_id": "def456",
   "system_configuration": { "driver_version": "1.0.0", "runtime_name": ".NET 8.0" },
-  "driver_connection_params": { "http_path": "/sql/1.0/warehouses/xyz", "host_info": { "host_url": "https://..." } },
+  "driver_connection_params": { "http_path": "/sql/1.0/warehouses/xyz", "host_info": { "host_url": "host.cloud.databricks.com", "port": 443 } },
   "auth_type": "pat",
   "sql_operation": { "statement_type": "STATEMENT_QUERY", "execution_result": "EXECUTION_RESULT_EXTERNAL_LINKS" },
   "operation_latency_ms": 254
@@ -2373,8 +2373,8 @@ Every field in the `OssSqlDriverTelemetryLog` proto must be populated and verifi
 |-------------|---------------|------------|
 | `http_path` | e.g. `"/sql/1.0/warehouses/abc123"` | Non-empty, starts with `/` |
 | `mode` | `DRIVER_MODE_THRIFT` or `DRIVER_MODE_SEA` | Not `UNSPECIFIED` |
-| `host_info.host_url` | e.g. `"https://host.cloud.databricks.com:443"` | Non-empty, starts with `https://` |
-| `host_info.port` | Port number (may be 0 if embedded in URL) | — |
+| `host_info.host_url` | e.g. `"host.cloud.databricks.com"` (bare hostname, matches JDBC) | Non-empty, no scheme, no port suffix |
+| `host_info.port` | Port number, e.g. `443` | > 0 |
 | `auth_mech` | e.g. `DRIVER_AUTH_MECH_PAT` | Not `UNSPECIFIED` |
 | `auth_flow` | e.g. `DRIVER_AUTH_FLOW_TOKEN_PASSTHROUGH` | Not `UNSPECIFIED` |
 | `enable_arrow` | `true` | Boolean |

csharp/src/Telemetry/ConnectionTelemetry.cs

@@ -346,7 +346,10 @@ internal static Proto.DriverConnectionParameters BuildDriverConnectionParams(
                 Mode = Proto.DriverMode.Types.Type.Thrift,
                 HostInfo = new Proto.HostDetails
                 {
-                    HostUrl = $"https://{host}:{port}",
+                    // Bare hostname, matching JDBC. Scheme is implicit (always https) and
+                    // port is reported in the sibling Port field, so including them here
+                    // was redundant and forced analysts to normalize across drivers.
+                    HostUrl = host,
                     Port = port
                 },
                 AuthMech = authMech,

csharp/test/E2E/Telemetry/ClientTelemetryE2ETests.cs

@@ -1114,7 +1114,9 @@ public void Telemetry_QueryExecution_CapturesAllFields()
                 Assert.NotEqual(AdbcDrivers.Databricks.Telemetry.Proto.DriverMode.Types.Type.Unspecified, connParams.Mode);
                 Assert.NotNull(connParams.HostInfo);
                 Assert.False(string.IsNullOrEmpty(connParams.HostInfo.HostUrl), "HostUrl should be populated");
-                Assert.Contains("https://", connParams.HostInfo.HostUrl);
+                // host_url is a bare hostname (matches JDBC). Scheme/port must not be embedded
+                // (PECO-2987). Port is reported separately in host_info.port.
+                Assert.DoesNotContain("://", connParams.HostInfo.HostUrl);
                 Assert.NotEqual(AdbcDrivers.Databricks.Telemetry.Proto.DriverAuthMech.Types.Type.Unspecified, connParams.AuthMech);
                 Assert.NotEqual(AdbcDrivers.Databricks.Telemetry.Proto.DriverAuthFlow.Types.Type.Unspecified, connParams.AuthFlow);
 

csharp/test/E2E/Telemetry/ConnectionParametersTests.cs

@@ -154,6 +154,72 @@ public async Task ConnectionParams_HostInfoPort_IsPopulated()
             }
         }
 
+        /// <summary>
+        /// Regression test for PECO-2987: driver_connection_params.host_info.host_url was
+        /// emitted as <c>"https://&lt;host&gt;:443"</c>, differing from JDBC which emits a bare
+        /// hostname. Analysts joining on host across drivers had to normalize. host_url must
+        /// now match JDBC: bare hostname, no scheme, no port suffix. Port is reported
+        /// separately in host_info.port.
+        /// </summary>
+        [SkippableFact]
+        public async Task ConnectionParams_HostInfoHostUrl_IsBareHostname()
+        {
+            CapturingTelemetryExporter exporter = null!;
+            AdbcConnection? connection = null;
+
+            try
+            {
+                var properties = TestEnvironment.GetDriverParameters(TestConfiguration);
+
+                // Resolve the expected host using the same precedence as DatabricksConnection.GetHost().
+                string? expectedHost = null;
+                if (properties.TryGetValue(SparkParameters.HostName, out string? hostName)
+                    && !string.IsNullOrEmpty(hostName))
+                {
+                    expectedHost = hostName;
+                }
+                else if (properties.TryGetValue(AdbcOptions.Uri, out string? uri)
+                    && !string.IsNullOrEmpty(uri)
+                    && Uri.TryCreate(uri, UriKind.Absolute, out Uri? parsedUri))
+                {
+                    expectedHost = parsedUri.Host;
+                }
+
+                Assert.False(string.IsNullOrEmpty(expectedHost),
+                    $"Test configuration must set {SparkParameters.HostName} or {AdbcOptions.Uri}");
+
+                (connection, exporter) = TelemetryTestHelpers.CreateConnectionWithCapturingTelemetry(properties);
+
+                using var statement = connection.CreateStatement();
+                statement.SqlQuery = "SELECT 1 AS test_value";
+                var result = statement.ExecuteQuery();
+                using var reader = result.Stream;
+
+                statement.Dispose();
+
+                var logs = await TelemetryTestHelpers.WaitForTelemetryEvents(exporter, expectedCount: 1);
+                TelemetryTestHelpers.AssertLogCount(logs, 1);
+
+                var protoLog = TelemetryTestHelpers.GetProtoLog(logs[0]);
+
+                Assert.NotNull(protoLog.DriverConnectionParams);
+                Assert.NotNull(protoLog.DriverConnectionParams.HostInfo);
+                string actualHostUrl = protoLog.DriverConnectionParams.HostInfo.HostUrl;
+
+                Assert.False(string.IsNullOrEmpty(actualHostUrl), "host_url should be populated");
+                Assert.Equal(expectedHost, actualHostUrl);
+                Assert.DoesNotContain("://", actualHostUrl);
+                Assert.DoesNotContain(":", actualHostUrl);
+
+                OutputHelper?.WriteLine($"✓ host_info.host_url: {actualHostUrl}");
+            }
+            finally
+            {
+                connection?.Dispose();
+                TelemetryTestHelpers.ClearExporterOverride();
+            }
+        }
+
         /// <summary>
         /// Tests that enable_arrow is set to true for ADBC driver.
         /// </summary>

docs/designs/fix-telemetry-gaps-design.md

@@ -123,7 +123,7 @@ flowchart TD
 |---|---|---|
 | `http_path` | Populated | |
 | `mode` | Populated | Hardcoded to THRIFT |
-| `host_info` | Populated | |
+| `host_info` | Populated | `host_url` is bare hostname (matches JDBC, PECO-2987); `port` reported separately |
 | `auth_mech` | Populated | PAT or OAUTH |
 | `auth_flow` | Populated | TOKEN_PASSTHROUGH or CLIENT_CREDENTIALS |
 | `use_proxy` | **NOT SET** | |