DTU went down for a while - caused sql server unaccessible

Question

Hello,

yesterey our production cloud had errors with accesing azure sql server (a few during one minute):

Type
  System.Data.SqlClient.SqlException
Message
  Database 'DriasDb' on server 'driassqlsrv' is not currently available.  Please retry the connection later.  If the problem persists, contact customer support, and provide them the session tracing ID of '735A122C-D952-41A6-89F4-A89477A44B03'.

In Azure Sql database metrics I found that DTU limit went down for that while:

I didn't do any changes to this servcie near that time. The pricing tier is 20 DTU.

Do you anybody know what can cause this?

I this normal behavior, that e.g. Azure Sql Server sometimes must be restarted and during this time is unaccesible?

If this is normal behaviour, how I can avoid it? Some trafic manager / load balancer for Azure Sql Database?

Thanks in advance for your answer.

Best Regards, Jindrich Pastorek

Answer 1

https://docs.microsoft.com/en-us/azure/sql-database/sql-database-single-database-scale

https://docs.microsoft.com/en-us/azure/sql-database/sql-database-dtu-resource-limits-single-databases

>>I this normal behavior, that e.g. Azure Sql Server sometimes must be restarted and during this time is unaccesible?

No, it does not need to be restarted at all,...

Can you contact  you r local MS office to shed some lights on the issue?

---

Best Regards,Uri Dimant SQL Server MVP, http://sqlblog.com/blogs/uri_dimant/

MS SQL optimization: MS SQL Development and Optimization
MS SQL Consulting: Large scale of database and data cleansing
Remote DBA Services: Improves MS SQL Database Performance
SQL Server Integration Services: Business Intelligence

Answer 2

This is definitely not the normal behavior. Please create a support ticket with Azure support and provide the session tracing ID to get to the root of this.

From your application point of view, you may want to incorporate retry logic to handle transient errors like these. The guidance is here if you are interested.

Answer 3

just test