Hi, I recently created an Azure Synapse workspace and was attempting to run a simple SQL query using the built-in serverless SQL pool. However, I encountered an issue where the built-in serverless SQL pool is displays internal error and is unavailable

Question

Hi, I recently created an Azure Synapse workspace and was attempting to run a simple SQL query using the built-in serverless SQL pool. However, I encountered an issue where the built-in serverless SQL pool is displays internal error and is unavailable

Kritika Tripathi 5

Screenshot 2026-06-24 185544

0 comments

2 answers

Your answer

Answer 1

Megha Ramakrishnan 325

Hi @Kritika Tripathi ,

When a newly created Azure Synapse workspace throws an "internal error" and shows the built-in serverless SQL pool as Unavailable, it is typically due to the following concerns.

Check the Synapse Workspace Firewall:

By default, Azure Synapse restricts public network access.

If your client IP is not explicitly allowed, the Synapse Studio UI will fail to communicate with the serverless backend, often masking the network block as a generic "internal error" or "unavailable" status.

Go to the Azure Portal and open your Synapse workspace.
In the left-hand menu under Security, click Networking.
At the top, click + Add client IP to automatically populate your current public IP address.
Check the box for Allow Azure services and resources to access this workspace if your query interacts with other Azure data sources.
Click Save and wait about 2–3 minutes for the rules to propagate.

Verify Port 1443/1433 Is Open on Your Network:

Synapse Studio requires outbound communication over TCP Port 1443 and UDP Port 53.
External tools (like SSMS or Power BI) require outbound communication over TCP Port 1433.

Trigger a Manual call:

Open a new SQL script window in Synapse Studio.

Run a non-storage query to force the backend to initialise:

SELECT 1;

Please 'Upvote'(Thumbs-up) and 'Accept' as answer if the reply was helpful. This will be benefitting other community members who face the same issue.

Thank you!

Kritika Tripathi 5 Reputation points

2026-06-26T06:15:54.7333333+00:00

Thanks a lot, but the issue still persists i have checked everything .
Megha Ramakrishnan 325 Reputation points

2026-06-26T06:31:58.1866667+00:00
Hi @Kritika Tripathi ,

Thank you for your response.

Can you please check if you are able to connect to it locally, using the below steps.

Go to the Azure Portal, open your Synapse Workspace, and look at the Overview page.

On the right side, find the Serverless SQL endpoint string (it will look like ⁠yourworkspace-ondemand.sql.azuresynapse.net⁠). Copy it.

Open SQL Server Management Studio (SSMS) or Azure Data Studio on your local machine.

Try to connect using these parameters:

Server type: Database Engine

Server name: [Paste your Serverless SQL endpoint]

Authentication: Microsoft Entra ID - Universal with MFA (or Azure Active Directory - Universal with MFA)

Login: Your Azure account email.

Thanks
Kritika Tripathi 5 Reputation points

2026-06-26T08:43:10.89+00:00

I ran Select 1 in SSMS,ran successfully . , I am able to connect locally.

Thank you
Kritika Tripathi 5 Reputation points

2026-06-26T11:00:23.75+00:00

When i ran Test-NetConnection -ComputerName <workspace>ondemand.sql.azuresynapse.net -Port 80 it shows false works fine with port 1443 and 443
Pilladi Padma Sai Manisha 10,945 Reputation points Microsoft External Staff Moderator

2026-06-30T07:26:36.3233333+00:00
Hi @Kritika Tripathi
Thank you for the update.

It's helpful to know that you were able to connect to the serverless SQL endpoint from SSMS and that SELECT 1 executed successfully. This confirms that the serverless SQL endpoint is operational and that connectivity from your machine is working as expected. The Test-NetConnection results also indicate that network connectivity is not the root cause, as communication over the required HTTPS/SQL ports is successful.

Since the built-in serverless SQL pool is still shown as Unavailable with an internal error in the Azure portal, while the endpoint itself is functioning, the issue appears to be isolated to the Synapse Studio/portal experience or the workspace state, rather than the serverless SQL engine.

To help narrow this down, could you please confirm the following?

Does the same Unavailable status appear in both the Azure portal and Synapse Studio, or only in one of them?

Has the built-in serverless SQL pool ever shown an Available status since the workspace was created?

Could you also try accessing the workspace in an InPrivate/Incognito browser session or a different browser to rule out any cached portal state?

For reference, Microsoft documents that the built-in serverless SQL pool can sometimes appear unavailable due to workspace networking, permissions, or workspace state issues, while connectivity to the endpoint can still be verified independently. You can find more details here:

Serverless SQL pool self-help guide

Connect to Synapse SQL

Connect to Synapse SQL using SSMS

Once we have the above information, we can better determine whether this is a portal-specific issue or whether further investigation into the workspace metadata is required.
Pilladi Padma Sai Manisha 10,945 Reputation points Microsoft External Staff Moderator

2026-07-01T02:06:43.0833333+00:00

Hi @Kritika Tripathi

Following up to see if the below answer was helpful. If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.

Answer 2

hi Kritika Tripathi & thx for sharing urs issue here at Q&A portal,

Since this is a new Synapse workspace and the built-in serverless SQL pool shows Unavailable with internal error, this is likely not caused by ur SQL query. The built-in serverless pool is managed by Synapse and should be available by default. If it’s unavailable before even running normal queries, that usually points to workspace provisioning/backend state, regional capacity/service issue, or a Synapse control-plane problem.

First try the boring stuff refresh Synapse Studio, sign out/in, open from Azure Portal again, and check from another browser. If it still shows Unavailable, check Azure Service Health for Synapse in that region.

https://learn.microsoft.com/en-us/azure/synapse-analytics/sql/on-demand-workspace-overview

https://learn.microsoft.com/en-us/azure/synapse-analytics/troubleshoot/troubleshoot-synapse-studio

If the workspace was just created, wait a bit and retry. Sometimes serverless metadata takes time to settle. But if it stays like this for hours, open a Synapse support case w/ workspace name, region, subscription ID, UTC time, screenshot, and any Activity Log correlation IDs.

Create another Synapse workspace in the same or diff region and see if the built-in pool comes up there. If the new one works, ur original workspace is prob stuck and needs backend cleanup.

rgds,

Alex

&

If my answer was helpful pls mark it and additional thx if u follow me at Q&A portal

and at my blog https://ctrlaltdel.blog/

Kritika Tripathi 5 Reputation points

2026-06-26T06:17:00.06+00:00

Thanks a lot , still facing the same issue. the sql pool is unavailable .