sql server error 17886 severity 20 state 1

Question

error 17886 severity 20 state 1

Answer 1

Hi，Charles DoveError 17886 severity 20 state 1 indicates that in a multi-user situation the client is experiencing an excess of parallel requests and does not have sufficient resources to accept new requests.

This is related to the client application's connection logic, excessive connection frequency, and the driver's request reconnection mechanism.

Add 'MultipleActiveResultSets=True' to your connection string.

Add 'Async=True' to your connection string.

Try these two methods. If the problem persists, you will need to examine the error log for connection details.

If there are no connection details in the error log, you will need to use the command

SELECT CAST(record AS XML) FROM sys.dm_os_ring_buffers WHERE ring_buffer_type = 'RING_BUFFER_CONNECTIVITY'

Connectivity Ring Buffer captures every connection closure initiated by the server, including every session that is abnormally interrupted or every login failure event. For effective troubleshooting, the Ring Buffer will attempt to correlate the client's failures with the server's closing actions.

Answer 2

The SQL Server error 17886 with severity 20 and state 1 typically indicates that there is an issue with the server's ability to authenticate a client connection. This error is generally related to the Kerberos authentication process. The root cause of this problem usually lies in the misconfiguration or failure of Kerberos authentication, which can involve issues such as incorrect service principal names (SPNs), problems with the domain controller, or issues with the server's or client's configuration in a domain environment. Essentially, it points to a breakdown in the security protocol required for establishing a trusted connection.

Here’s a deeper look into the potential causes and aspects of this problem:

Kerberos Authentication Issues

1. Service Principal Name (SPN) Misconfiguration: SPNs are unique identifiers for services running on servers. For Kerberos authentication to work correctly, the SPNs must be correctly configured. If there's a mismatch or duplication, the server may fail to authenticate the connection properly.
2. Domain Controller Problems: The Domain Controller (DC) plays a crucial role in the Kerberos authentication process. If there are issues with the DC, such as connectivity problems, configuration errors, or replication issues, it can prevent the server from successfully authenticating users.
3. Clock Skew: Kerberos is sensitive to time discrepancies. If there’s a significant difference between the system clocks of the server and the DC, authentication requests can fail because the time stamps in the Kerberos tickets will be considered invalid.
4. Delegation Settings: Kerberos delegation allows a service to use the end-user credentials to access resources on behalf of the user. Incorrect delegation settings can cause authentication failures.
5. DNS Configuration: Proper DNS configuration is essential for Kerberos authentication. Incorrect DNS settings can lead to the inability to resolve the correct addresses needed for the authentication process.

Configuration and Environmental Factors

1. Server and Client Configuration: Both the server and client need to be correctly configured for Kerberos authentication. Misconfigurations on either side can lead to failures. This includes ensuring that the server is properly registered in the Active Directory.
2. Network Issues: Network connectivity issues between the client, the server, and the DC can disrupt the authentication process. This includes firewalls, network segmentation, or other network-related problems.
3. Security Policies: Group policies and security settings within the domain environment can impact Kerberos authentication. Incorrect policies can restrict the necessary permissions or settings required for successful authentication.

Error Impact

• Severity 20: Indicates a fatal error in the current process, and the connection will be terminated.
• State 1: Provides specific information about the type of error and its context within the SQL Server environment.

Troubleshooting Steps

Understanding the error requires a comprehensive approach:

1. Check SPN Registration: Verify that SPNs for the SQL Server instance are correctly registered in Active Directory.
2. Verify Domain Controller Health: Ensure the DCs are operating correctly and there are no replication or connectivity issues.
3. Time Synchronization: Ensure that the server, client, and DC are synchronized to the same time source.
4. DNS Configuration: Check DNS settings and ensure that they are correctly configured.
5. Review Security Policies: Examine group policies and security settings that might affect Kerberos authentication.
6. Network Configuration: Ensure that there are no network issues preventing communication between the server, client, and DC.

Understanding and resolving SQL Server error 17886 involves investigating these areas and ensuring that all components of the Kerberos authentication process are correctly configured and functioning.