Switching from Local SQL to Azure SQL Database on Azure VM - Lower performance

1
votes

Currently I am hosting my online application on an Azure VM. This is a pretty standard Umbraco website with around 300 visitors per day, nothing special here.

Details of Azure VM: - Basic A3 - 4 cores - 7 GB Memory

In the current situation MsSQL is installed on the VM itself and this is working fine, but I am not a great expert in maintenance. A solution I found is migrating the SQL database to SQL Azure.

Looking at my current website I decided to do this and I migrated the database to SQL Azure: - S3 Standard - 100 DTU - 250GB

After the migration I switched the connection string with the connection string that was provided in the Azure portal. When I reloaded my website the loading time was suddenly three times slower.

For now I switched it back to the local SQL Database, but I am wondering if it is a normal situation that the local SQL is faster then SQL Azure in this case.

I hope someone can answer my question, please let me know if more information is required to answer my question.

Best regards, Martijn

EDIT The issue is resolved! I found out that the SQL Azure Server that I created was located in a different region then the Azure VM. After I created a new SQL Azure server in the same region the performance issues where fixed.

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sqlazureumbracoazure-sql-database
Very odd; an s3 should give yor a lot more performance than you need for your scenario. The azure portal has pretty good tools for tracking down slow queries; I recommend you review to find out why it is so slow. – flytzen
good to hear that reason,worth adding to checklist – TheGameiswar

1 Answers

1
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Good to hear your perf issues are fixed. In general, comparing the performance of a local database versus a PaaS database is not always an apples-to-apples comparison for a number of reasons:

  • Azure SQL Database is a highly available service (99.99%) that requires synchronous commits to a secondary database. A local database typically is not configured for high availability.
  • Azure SQL Database provides automatic backup. Depending on your setup, a local database might may or may not be configured for backup.
  • The affect of network latency on a local database does not exist
  • The memory and CPU between of a S3 Azure SQL Database and a A3 VM are likely not the same