I have a problem which I already looking at it for a few days and still have no solution.
I found this exception in my C# web app log.
[2015-12-03 13:56:06] [ERROR] [] [Error occurred during execution of
'Server Bootstrapper' component. Execution will be retried (attempt
120 of 2147483647) in 00:05:00 seconds.]
[System.Data.SqlClient.SqlException (0x80131904): Login failed for
user "A Network account".
It appears to me that it is using the network account to access the SQL database and because that network account is not granted access to the database, hence login failed and server cannot startup.
However, when I go to the Hangfire dashboard, I can see the recurring jobs, which seems to me that hangfire can access the database with the right account for retrieving the recurring jobs.
Also, in the IIS server, we already set the Identity to "ApplicationPoolIdentity" for the application pools. Hence, we should use the virtual account instead of the network account.
May I know anyone has the similar problem and have the solution. Really appreciate for your help!!
I ran into the same issue using Hangfire with SQL Server and EntityFramework Code First where EntityFramework was responsible for creating the database, so this suggestion is based purely off of that scenario.
If you are using EF Code First, your database isn't created until the context is created and accessed for the first time.
This means that at App Start your database might not exist. Hangfire won't create the database, it only creates the tables in an already existing database.
So what you might be seeing is:
No database exists.
Your app start's up and Hangfire tries to get itself running, the server process throws an error because EF hasn't created the DB.
The web application start finishes since the hangfire service crashing isn't fatal to the application.
Something in your web app calls into EntityFramework.
EF runs and creates the database (likely no hangfire tables at this point)
you access the hangfire dashboard, hangfire is now able to connect, and see the tables don't exist, so it creates them. (now you will see the tables in your db)
The dashboard can now see the database and show you the stats (likely 0 servers running) so it seems like everything is working.
The way I solved it was to make sure that even if the database is empty (not tables), it is at least created. This was hangfire can access it to install it's tables and start, and EF can access it, and create it's schema.
Also, (and this probably isn't it), GlobalConfiguration.Configuration.UseSqlServerStorage() should run first before other Hangfire startup configuration.
Hope that helps!
Steve
You should create background job server instance, see document here
In my case, the server name was too long and there was a SQL error saying it would be truncated. I was only able to see this error after starting it with Just My Code turned off in Visual Studio.
Moral of the story: Use a shorter name for the server and don't append your own unique-per-instance identifiers to it so it can't run into a truncate error. The column is an nvarchar(100).
Related
I have a project where users upload multiple 4-6MB AccessDb files to migrate into a AWS hosted SQL Server database. I think what is happening is that IIS maybe shutting down the process after some amount of time.
Its basically a file upload and then a c# static class that reads the mdb file and uses EF .core to copy into SQL Server. Using Visual Studio, i don't see any shutdowns and all test files migrate successfully.
Website built using .netcore 2.1 / c#
I have Web.config timeout set to requestTimeout="00:59:00" so that basically stops some 503 errors.
What I'm seeing is that if all browsers are closed(or maybe not) and maybe technically no connections to IIS, that after a few minutes, the migration stops. I'm not seeing new rows added to the database.
I want my c# .netcore processes to continue migrating whatever databases the user uploaded without IIS or whatever other process killing the connection.
Looking for tips I can update. I'm assuming there's other Web.config settings I can update?
It sounds like your code that processes the files is a background job in your application, so I think I know what's going on.
By default, IIS app pools are configured to shut down after 20 minutes of inactivity (no incoming requests). You need to disable that.
The option is called "Idle Time-out (minutes)" in the Advanced Settings of the application pool. Set it to 0 to disable it.
There are also options in there to automatically refresh the app pool, so review those and make sure they are acceptable to you (I forget what the defaults are).
It's not a good design decision to keep an http connection open for that long. First of all asp.net core will drop the thread after a while, and second the user could drop the connection by mistake. I would recommend doing this async to the user:
Receive the file, validate it.
Schedule a background job using either Hangfire or the builtin
IHostedService interface.
When the migration is complete email or notify the user some other
way.
I get the following generic Timeout expired error in my .NET Application when I run a program which does an update to the database.
In SQL Server Activity Monitor, when this error appears, it shows there is a lock on the database shown in the next image.
Any idea what could be going on here? I think it is permissions related because when I log on with my Windows Administrator account, it runs through fine and doesn't error out. Also, I don't think it is really a time out issue as SQL Server is set to time out after 10 minutes and so are the Sql Commands I create in my code.
Any ideas, what permissions I would need to change to stop this from happening for my users?
The issue was resolved by logging in as an Administrator, so permissions related.
I have a distributed application with multiple processes on multiple servers connect to a SQL Server database.
I need to migrate the database schema in code during first startup, because upgrade deployment can be done with the user without database access (we use computer object database access).
Currently this is done by providing a sql file with statements and then a user with db access (but potentially without app access) would run this independently.
Because apps do not talk to each other (firewalls, different DCs etc.) I was thinking that i'd have to designate one server as 'master', all others as 'slaves' and then on the master the first process that'd start would obtain the mutex and do the schema migrations; all others could simply wait until they can see the schema is migrated.
However, this has a certain code smell to me.
I tried researching how Entity Framework handles this in code first migrations and seems they don't (e.g. if two processes start at exact same time they would both try to migrate schema).
Any other approaches?
You can change mode of database to single-user (other connections) will be refused. Make the changes and then change back multi-user mode.
EDIT:
There is trick, how to get "mutex". You can update/delete record(s). Until transaction is open, the exclusive lock is stil holded. Probably, if you delete 0 records (with table-lock hint) from every table in transaction, you probably achieve same behaviour as "global mutex" for the users of database. But I don't know what behaviour will be with schema changes.
I made an ASP.NET Web API project in VS2013 with one controller. The setup uses Entity Framework Code First.
When I run it locally, it works fine. But when I publish it to Azure Web App, calls to the controller will wait for a long time or returns an error An error has occurred.
I removed codes which work with DB and it works again.
The plan has 1GB of storage and I want to use it rather than paying for a separate database service.
How can I debug it to see what happens on the server with the database?
Thanks.
You can set your connection string in Azure control panel which will be used instead of one in your web.config.
You can also turn on error reporting in your web.config file to see if you are getting the 26 - Database not found error (connection timeout).
I have a C# application that uses a localhost DB (MySQL).
Now, when I create the executable I´m assuming that the receptor computer MUST have the exact DB with the the same name and tables, also, must have running WAMP or XAMPP.
If one of this conditions is not accomplished the program will crash horribly, with the errors of Windows/C#.
I could put exceptions for every case, but I´m fearful that I would hide other errors putting exceptions for everything!
With production software, how do you manage this? With exceptions? Writing a manual for the user? etc?
During bootstrapping, I recommend check to see if a DB Connection can be created (in my case, SQL Server), given the database connection string defined in an app.config. Initially, you should do some version checking on the database. If the database can't be found, attempt to create it. if i'ts out of date, attempt to upgrade it. If this process fails, then your database engine instance isn't installed or is unresponsive. For my application case, I exit the program, as there's nothing else to do if the DB can't be accessed.
Once past this point, I generally assume that the DB connection is active.