How ArcGIS Server manages connection pool in SQL Server

[gisarchitect]

Hello Everyone,

I am seeking insights on how ArcGIS Server manages connections to SQL Server when serving feature services, particularly in the context of SQL Server Standard Edition licensing constraints.

Scenario:

• I have a feature service that references an enterprise geodatabase hosted in SQL Server.
• This feature service is accessed by approximately 20 users via Portal for ArcGIS, with ArcGIS Server acting as the hosting server.
• The feature service is configured with a maximum of 20 instances.

Questions:

1. Connection Pooling and Management:

   • How does ArcGIS Server handle database connections in this scenario? Does it use connection pooling to manage and reuse connections efficiently?
   • If 20 users are accessing the feature service simultaneously, does this result in 20 individual connections to SQL Server, or are connections pooled and shared across instances?

2. Service Instance Configuration:

   • Given that the feature service has a maximum of 20 instances, does this configuration imply that up to 20 connections could be established with the SQL Server, assuming high load?
   • What best practices can be followed to configure the minimum and maximum number of service instances to optimize connection usage?
3. Registered connection files in ArcGIS Server:

According to Microsoft, every user or device accessing SQL Server software, whether virtual or physical, must be licensed with a SQL Client Access License (CAL). This requirement extends to users and devices accessing the SQL Server software indirectly through another application or hardware device. My question is: When multiple geodatabases are registered from the same SQL Server instance, does this count as multiple users even if they are connected using the same SQL Server user account?
In other words, should I license only the single SQL Server user account used for registering the geodatabases, or should I license based on the number of connections in the connection pool?

1. Licensing Implications:

   • Considering that SQL Server Standard Edition has licensing constraints based on the number of connections, how can I ensure compliance and avoid exceeding these limits?
   • Are there recommended strategies or configurations to manage and limit the number of concurrent connections to SQL Server in such a setup?

Thank you for your assistance.