Remedy - Server - AR Server Performance degrade and receives [DBNETLIB][ConnectionWrite (send()).]General network error. Check your network documentation. (SQL Server 11)

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    PRODUCT:

    Remedy AR System Server


    COMPONENT:

    AR System


    APPLIES TO:

    BMC Remedy AR System Server



    PROBLEM:

     

    AR server degrades progressively, and in arerror.log, there are a lot of the following messages:

    {Date Time} 390620 : SQL database is now available (ARNOTE 592)
    {Date Time}  390620 : SQL database is now available (ARNOTE 592)
    {Date Time}  390620 : Failure during SQL operation to the database (ARERR 552)
    {Date Time}  [DBNETLIB][ConnectionWrite (send()).]General network error. Check your network documentation. (SQL Server 11)

     


    SOLUTION:

     

    Legacy ID:KA354669

         

    According to this KB, this issue occurs because Windows Server and later versions implement a security feature that reduces the size of the queue for concurrent TCP/IP connections to the server. This feature helps prevent denial of service attacks. Under heavy load conditions, the TCP/IP protocol may incorrectly identify a valid TCP/IP connections as a denial of service attack. This behavior may lead to the issue that is described in the "Symptoms" section.

      

    To resolve this issue:
    1- Turn off this new functionality by adding the SynAttackProtect entry to the following registry key on the computer that is running Microsoft SQL Server that houses your Application Server databases.
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

    2- Set the SynAttackProtect entry to a DWORD value of 00000000. To do this, follow these steps:
         a) Click Start, click Run, type regedit, and then click OK.
         b) Locate and then click the following registry key:
             HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
         c) On the Edit menu, point to New, and then click DWORD Value.
         d) Type SynAttackProtect, and then press ENTER.
         e) On the Edit menu, click Modify.
         f) In the Value data box, type 00000000. Click OK.
         g) Quit Registry Editor.

      


    Additional Information:
    > Issue with the Network which is causing the connection between the server and database to drop. Please check with your Network team if they had any issues on the network at that time.

    > The database server is actually dropping the connection from the AR Server due to some reason. This may be due to some Microsoft patches applied on the database server. Please check with the DBA if they can find if the database server is disconnecting the sessions from the AR Server.

    > In case the database and the AR Server are on different servers and there is a Network device like Switch, router or Load Balancer between them, they can also drop the connections. Please check with the Network administrator if that is the case. The Firewalls normally have a setting to disconnect idle sessions, make sure not such setting is enabled in case there is a Firewall or Load Balancer between the AR Server and database server.
     

     


    Article Number:

    000086223


    Article Type:

    Solutions to a Product Problem



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