C# SqlServer database connection problem while deploying to AppEngine

[Krzysztof Patra]

Hi

I have this problem when trying to deploy to AppEngine. On local machine using proxy it works fine.

Microsoft.EntityFrameworkCore.Database.Connection[20004]

A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 40 - Could not open a connection to SQL Server)

An error occurred using the connection to database 'dblivtron' on server 'cloudsql'.

My config:

Appengine Flexible API = enabled

Cloud SQL Admin API = enabled

Instance public address = enabled

Instance Connection Name: livtron-testproject:europe-west1:livtrondbinstance

Data base: dblivtron

My app.yaml:

runtime: custom

env: flex

manual_scaling:

  instances: 1

resources:

  cpu: 1

  memory_gb: 0.5

  disk_size_gb: 10

beta_settings:

  cloud_sql_instances: livtron-testproject:europe-west1:livtrondbinstance=tcp:3306

  

My connection string in appsettings.json  

  "ConnectionStrings": {

    "DefaultConnection": "Server=cloudsql;Database=dblivtron;User Id=sqlserver;Password=#####;MultipleActiveResultSets=true;Encrypt=false;Pooling=true;"

  },

[George (Cloud Platform Support)]

You mention a proxy? Is your local machine behind a proxy? That would be consistent with the error you keep receiving. Does the situation change if you access App Engine without a proxy, from another network?

It may be worthwhile having a look at Configuring Cloud SDK for use behind a proxy/firewall. 

[Krzysztof Patra]

I think I found the real problem. It was connected to MultipleActiveResultSets=true. 

When I commented some code that was generating "the multiple batches on a single connection situation" on starting of the app, the deployment to Appengine got successful.

Does Google Cloud SqlServer have problem with it?   

[Shawn Wu]

A batch is a SQL string that you send for execution to SQL Server. It can contain multiple statements. Every time you call SqlCommand.Execute* you send a single batch.