Is Trace Flag 1117 enabled in Azure Managed Instance?

-> The list of trace flags enabled by default in an Azure Managed Instance doesn’t contain trace flag 1117.

-> The official documentation states that “A Managed Instance runs with all of the features of the most recent version of SQL Server, including online operations, automatic plan corrections, and other enterprise performance enhancements.”. This advises us that features related to trace flag 1117 should be enabled by default even though the trace flag is not explicitly enabled.

-> Lets check if this is actually true!

-> Managed instance that I am testing has below Tempdb files,

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-> I am inserting some data into a temporary table and check if all the tempdb files grow,

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-> It is pretty clear that all the tempdb files have grown. Lets check the SQL Server error log to see if there are any messages related to Tempdb autogrow,

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-> The messages recorded above shows us that autogrow has happened.

-> This proves that the features related to trace flag 1117 are enabled in the managed instance and it is not required for us to enable it explicitly.

Thank You,
Vivek Janakiraman

Disclaimer:
The views expressed on this blog are mine alone and do not reflect the views of my company or anyone else. All postings on this blog are provided “AS IS” with no warranties, and confers no rights.

Trace Flags enabled in Azure Managed Instance

-> There are many trace flags enabled by default in Azure Managed Instance.

Blog41_1.PNG

-> At this point, I am not sure if these trace flags will be enabled after the preview. But I can see trace flags that are used to write finer details to errorlog. So I think these may be removed later.

-> Lets see what these trace flags do. Some details can be incorrect, I will change it going forward as required.

Trace Flag Description
1800 1)  Details related to SQL Server startup.
2) This article mentions this trace flag which is related to “Slow synchronization when disks have different sector sizes for primary and secondary replica log files in SQL Server AG and Logshipping environments”
2551
2591
3004 Lists the database Backup / restore details step by step.
3447
3605 Redirects output to SQL Server errorlog
3701 Script level upgrade scripts will be written to SQL Server errorlog during failures. This gets added automatically to On-Premise SQL Server during patching.
3978
4141
5521
7838
8015  Ignores physical NUMA detection. This article has more details.
8017  Avoid creating a lot of offline schedulers.
8037
8054
8057
8063
8065
8086
9041
9537
9570
9837 Details related to checkpoint
9850 Details related to checkpoint
9883
9905
9934
9940
9941

Thank You,
Vivek Janakiraman

Disclaimer:
The views expressed on this blog are mine alone and do not reflect the views of my company or anyone else. All postings on this blog are provided “AS IS” with no warranties, and confers no rights.