Fix to (re)enable lower-privilege connection strings

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Updates
 
 * Fix SQL retry logic to open a new connection if a previous failure closed the connection ([#221](https://github.com/microsoft/durabletask-mssql/pull/221)) - contributed by [@microrama](https://github.com/microrama)
+* Fix to (re)enable lower-privilege connection strings ([#234](https://github.com/microsoft/durabletask-mssql/pull/234))
 
 ## v1.3.0
 

src/DurableTask.SqlServer/DTUtils.cs

@@ -196,6 +196,7 @@ public static bool HasPayload(HistoryEvent e)
             return historyEvent.EventType switch
             {
                 EventType.ExecutionStarted => ((ExecutionStartedEvent)historyEvent).Version,
+                EventType.SubOrchestrationInstanceCreated => ((SubOrchestrationInstanceCreatedEvent)historyEvent).Version,
                 EventType.TaskScheduled => ((TaskScheduledEvent)historyEvent).Version,
                 _ => null,
             };

src/DurableTask.SqlServer/Scripts/logic.sql

@@ -1444,7 +1444,7 @@ BEGIN
     -- Instance IDs can be overwritten only if the orchestration is in a terminal state
     IF @existingStatus NOT IN ('Failed')
     BEGIN
-        DECLARE @msg nvarchar(4000) = FORMATMESSAGE('Cannot rewing instance with ID ''%s'' because it is not in a ''Failed'' state, but in ''%s'' state.', @InstanceID, @existingStatus);
+        DECLARE @msg nvarchar(4000) = FORMATMESSAGE('Cannot rewind instance with ID ''%s'' because it is not in a ''Failed'' state, but in ''%s'' state.', @InstanceID, @existingStatus);
         THROW 50001, @msg, 1;
     END
 

src/DurableTask.SqlServer/SqlDbManager.cs

@@ -177,10 +177,22 @@ async Task<DatabaseLock> AcquireDatabaseLockAsync(bool createDatabaseIfNotExists
 
         async Task EnsureDatabaseExistsAsync()
         {
-            // Note that we may not be able to connect to the DB, let alone obtain the lock,
+            // Note that we may not be able to connect to the target DB, let alone obtain the lock,
             // if the database does not exist yet. So we obtain a connection to the 'master' database for now.
+            // If the current connection doesn't have permission to access the master database, this will fail.
+            // The exact error we see is hard to predict, so we catch SqlException and log a generic message.
             using SqlConnection connection = this.settings.CreateConnection("master");
-            await connection.OpenAsync();
+            try
+            {
+                await connection.OpenAsync();
+            }
+            catch (SqlException)
+            {
+                this.traceHelper.GenericInfoEvent(
+                    "Failed to connect to the master database. Skipping database exists check.",
+                    instanceId: null);
+                return;
+            }
 
             if (!await this.DoesDatabaseExistAsync(this.settings.DatabaseName, connection))
             {