Frequent disconnectivity issue

Hi ,

We have two app servers Aap3 & Aap4.(Microsoft Dynamics app). The Database server is SQL Server 20014. Standard edition. The application accsessing the multiple dbs in db server. From couple of days users complaining that they facing frequent disconnectivity to SQL.

From Microsoft Dynamics the connection string time out setting is 30sec.
In the SQL Server -Properties--Connections--Allow remote connections to this server is 600.
Thier is no veeam backup or snapshot is goingon during the disconnectivity.
CPU/Memory utilization from our moniting software during this time frame also looks fine.

Also another observation from App03 and APP04 event viewer, this SQL disconnect from application servers are happening frerquenlty even if there is no issue reported by user., comparing the time frame of APP03 and APP04, time of these SQL disconnect event is not same that means if SQL serever in freeze, typcially both application servers should see the same event logs of SQL disconnection, that says there is something that application is causing the SQL DB reconnects when this issue occur.

Further reading dynamics configuration file, the timeout to SQL is set as 30s on application server, can we set this as 60s on application configuration ?

FromSQL DB configations and is their anything else I can recommend if there is any optimization we can do from SQL DB side ??

From Event viewer i found this below error.

The “error 26073 - TCP connection closed but a child process of SQL Server may be holding a duplicate of the connection's socket” Consider enabling the TCPAbortiveclose SQL Server registry setting and restarting the SQL Server.if problem p[lease contact technical support.

When i googled this error some says applu CU as per below link.

Shall i suggest CU to customer? Or do i need to suggest increase the time out setting to 60 sec in Dynamics? or Any SQL Server i can perform any changes?

Please guide. What and all i can do to resolve the issue?


Better to start with increasing the timeout value.

Thank you so much for ur kind reply.
Any other things i can do from SQL Server configuration side? (Remote connecction setting/ CU ??)
What and all i can check to confirm the issue and resolution?

Also pls can you guide me in what situations we can go ahead with CU/Patches etc?

you need to check the KB for the known issue and if your product comes under the applied to section.

When i checked the Version. Below are the details.

Microsoft SQL Server 2014 (SP1-GDR) (KB4019091) - 12.0.4237.0(x64)
Jul 5 20017 22:03
Standard edition(64bit) on windows NT 6.3 (build 9600:) (Hypervisor)