DbMigrator will not be functional anymore if you decide to use Hangfire as Background Worker/Job #2940

5 Answer(s)

• 

  0

  liangshiwei created 2 years ago

  Support Team Fullstack Developer

  Hi,

  I think you should create a database first, hangfire will not create a database for you.

  See: https://github.com/HangfireIO/Hangfire/blob/master/src/Hangfire.SqlServer/Install.sql

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• 

  0

  raif created 2 years ago

  Hi,

  I think you should create a database first, hangfire will not create a database for you.

  See: https://github.com/HangfireIO/Hangfire/blob/master/src/Hangfire.SqlServer/Install.sql

  Hi, Of course we need to create DB first in place. Dbmigrator console application already exists to facilitate this database create operation, right ?

     public async Task StartAsync(CancellationToken cancellationToken)
      {
          using (var application = await AbpApplicationFactory.CreateAsync<hangfireDbMigratorModule>(options =>
          {
             options.Services.ReplaceConfiguration(_configuration);
             options.UseAutofac();
             options.Services.AddLogging(c => c.AddSerilog());
          }))
          {
              **await application.InitializeAsync();**
  
              await application
                  .ServiceProvider
                  .GetRequiredService<hangfireDbMigrationService>()
                  .MigrateAsync();
  
              await application.ShutdownAsync();
  
              _hostApplicationLifetime.StopApplication();
          }
      }
  

  So let me go step by step. Console application is going to initialize modules. Right ?

  That means whenever you use Volo.Abp.BackgroundWorkers.HangFire and/or Volo.Abp.BackgroundJobs.HangFire you will also run OnPreApplicationInitialization method. Right ?

  public async override Task OnPreApplicationInitializationAsync(ApplicationInitializationContext context)
  {
      var options = context.ServiceProvider.GetRequiredService<IOptions<AbpBackgroundWorkerOptions>>().Value;
      if (!options.IsEnabled)
      {
          var hangfireOptions = context.ServiceProvider.GetRequiredService<IOptions<AbpHangfireOptions>>().Value;
          hangfireOptions.BackgroundJobServerFactory = CreateOnlyEnqueueJobServer;
      }
      
      await context.ServiceProvider
          .GetRequiredService<IBackgroundWorkerManager>()
          .StartAsync(); 
  }
  
  public override void OnPreApplicationInitialization(ApplicationInitializationContext context)
  {
      AsyncHelper.RunSync(() => OnPreApplicationInitializationAsync(context));
  }
  

  More or less whenever you start BackgroundWorkerManager you will also going to try to create **BackgroundJobServer **

  await context.ServiceProvider
      .GetRequiredService<IBackgroundWorkerManager>()
      .StartAsync();
  

  And **BackgroundJobServer **ceration requires JobStorage .Btw BackgroundJobServer constructor used in the abp package is the obsolete one

  private BackgroundJobServer CreateJobServer(IServiceProvider serviceProvider)
  {
      Storage = Storage ?? serviceProvider.GetRequiredService<JobStorage>();
      ServerOptions = ServerOptions ?? serviceProvider.GetService<BackgroundJobServerOptions>() ?? new BackgroundJobServerOptions();
      AdditionalProcesses = AdditionalProcesses ?? serviceProvider.GetServices<IBackgroundProcess>();
  
      return new BackgroundJobServer(ServerOptions, Storage, AdditionalProcesses,
          ServerOptions.FilterProvider ?? serviceProvider.GetRequiredService<IJobFilterProvider>(),
          ServerOptions.Activator ?? serviceProvider.GetRequiredService<JobActivator>(),
          serviceProvider.GetService<IBackgroundJobFactory>(),
          serviceProvider.GetService<IBackgroundJobPerformer>(),
          serviceProvider.GetService<IBackgroundJobStateChanger>()
      );
  }
  

  If you don't define any JobStorage that will cause exception about JobStorage can't be null exception

  GlobalConfiguration.Configuration
      .UseSqlServerStorage(configuration.GetConnectionString("Default"));
  

  If you define JobStorage then it will going to execute https://github.com/HangfireIO/Hangfire/blob/master/src/Hangfire.SqlServer/Install.sql scripts.

  And as you already aware of that, scripts requires database in first place.

  And if you remember we are about create DB :)

  Long of short: Your Volo.Abp.BackgroundWorkers.HangFire and/or Volo.Abp.BackgroundJobs.HangFire are killing DbMigrator functionality by their nature of design.

  Steps to reproduce the issue :

  1. Create new application by using application template
  2. Add Hangfire.SqlServer package for job persistence
  3. Add Volo.Abp.HangFire (this should enough to force convert existing background jobs into the hangfire one like tokencleanup etc)
  4. Define connection string for job storage
  5. Run Db Migrator

  

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• 

  0

  liangshiwei created 2 years ago

  Support Team Fullstack Developer

  Hi,

  I'm sorry for that, yes the DBMigrator is used to create a database and tables.

  But it is only used to create ABP's database tables, not Hangfire.

  It looks like that Hangfire will prioritize execution and break the application, but this is designed by hangfire, I recommend you to use the second database for Hangfire server.

  If you want to use DBMigrator to create both an application database and a hangfire database, you need to do some extra things.

  For example:

  private string GetHangfireConnectionString()
  {
      // Server=(LocalDb)\\MSSQLLocalDB;Database={0};Trusted_Connection=True
      var connectionStringFormat = configuration.GetConnectionString("Hangfire");
      // Hangfire
      var dbName = configuration["HangfireDbName"];
  
      using (var connexion = new SqlConnection(string.Format(connectionStringFormat, "master")))
      {
          connexion.Open();
  
          using (var command = new SqlCommand(string.Format(
              @"IF NOT EXISTS (SELECT name FROM sys.databases WHERE name = N'{0}') 
                              create database [{0}];
                ", dbName), connexion))
          {
              command.ExecuteNonQuery();
          }
      }
  
      return string.Format(connectionStringFormat, dbName);
  }
  
  var connectionString = GetHangfireConnectionString();
  GlobalConfiguration.Configuration.UseSqlServerStorage(connectionString); 
  

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  1
• 

  0

  liangshiwei created 2 years ago

  Support Team Fullstack Developer

  BTW, I recommend that you install Volo.Abp.BackgroundWorkers.HangFire package in the startup project(.MVC, .HttpApi.Host etc..). this way it does not affect the DbMigrator project.

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• 

  0

  raif created 2 years ago

  I recommend you to use the second database for Hangfire server.

  Yeah, you are right using separate database for Hangfire most effective solution.

  BTW, I recommend that you install Volo.Abp.BackgroundWorkers.HangFire package in the startup project(.MVC, .HttpApi.Host etc..). this way it does not affect the DbMigrator project

  Noted.

  Cheers

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