Added null check for DistributedLock

shared/EShopOnAbp.Shared.Hosting.Microservices/DbMigrations/EfCore/PendingEfCoreMigrationsChecker.cs

@@ -1,15 +1,14 @@
-using System;
-using System.Linq;
-using System.Threading.Tasks;
-using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.DependencyInjection;
 using Serilog;
+using System;
+using System.Linq;
+using System.Threading.Tasks;
 using Volo.Abp.Data;
 using Volo.Abp.DistributedLocking;
 using Volo.Abp.EventBus.Distributed;
 using Volo.Abp.MultiTenancy;
 using Volo.Abp.Uow;
-using Volo.Abp.VirtualFileSystem;
 
 namespace EShopOnAbp.Shared.Hosting.Microservices.DbMigrations.EfCore;
 
@@ -41,7 +40,7 @@ public abstract class PendingEfCoreMigrationsChecker<TDbContext> : PendingMigrat
 
     public virtual async Task CheckAndApplyDatabaseMigrationsAsync()
     {
-        await TryAsync(LockAndApplyDatabaseMigrationsAsync); 
+        await TryAsync(LockAndApplyDatabaseMigrationsAsync);
     }
 
     protected virtual async Task LockAndApplyDatabaseMigrationsAsync()
@@ -49,6 +48,13 @@ public abstract class PendingEfCoreMigrationsChecker<TDbContext> : PendingMigrat
         await using (var handle = await DistributedLockProvider.TryAcquireAsync("Migration_" + DatabaseName))
         {
             Log.Information($"Lock is acquired for db migration and seeding on database named: {DatabaseName}...");
+
+            if (handle is null)
+            {
+                Log.Information($"Handle is null because of the locking for : {DatabaseName}");
+                return;
+            }
+
             using (CurrentTenant.Change(null))
             {
                 // Create database tables if needed

shared/EShopOnAbp.Shared.Hosting.Microservices/DbMigrations/MongoDb/PendingMongoDbMigrationsChecker.cs

@@ -64,10 +64,16 @@ public class PendingMongoDbMigrationsChecker<TDbContext> : PendingMigrationsChec
         var result = false;
         await using (var handle = await DistributedLockProvider.TryAcquireAsync("Migration_" + DatabaseName))
         {
-            Log.Information($"Lock is acquired for db migration and seeding on database named: {DatabaseName}...");
-
             using (var uow = UnitOfWorkManager.Begin(requiresNew: true, isTransactional: false))
             {
+                Log.Information($"Lock is acquired for db migration and seeding on database named: {DatabaseName}...");
+
+                if (handle is null)
+                {
+                    Log.Information($"Handle is null because of the locking for : {DatabaseName}");
+                    return false;
+                }
+
                 async Task<bool> MigrateDatabaseSchemaWithDbContextAsync()
                 {
                     var dbContexts = ServiceProvider.GetServices<IAbpMongoDbContext>();