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Home > Success Center > Netflow Traffic Analyzer (NTA) > NTA - Knowledgebase Articles > Connection to NTA Flow Storage Database has been lost

Connection to NTA Flow Storage Database has been lost

Updated: March 8, 2018


This article describes the issue when after installing NTA 4.2, you lose connection to the NTA Flow Storage database running on Fastbit.


  • NTA 4.2
  • For Cause 2: VMWare ESXi 6.0; SQL 2014 SP2 build 12.0.5000.0


  • The NTA module on the main NPM server is different then the one on FastBit (Flow storage database)
  • Performance issue on SQL and/or Flow Storage database

    Exceptions NetFlowPacketWorkflowManager - Error flushing data found in NTA.BusinessLayer.log


There are two different types of resolution, depending on the cause of the issue.

Cause 1

Upgrade the NTA module on NPM server to 4.2 using the same installer.

Cause 2

To fix exceptions in NTA.BusinessLayer.log, follow the steps below:

  1. Upgrade the SQL server from 2014 SP2 build 12.0.5000.0 to 2014 SP2 CU4 build 12.0.5540.0.
  2. Back up the Orion database.
  3. Stop the NetFlow service.
  4. Run the TRUNCATE table dbo.NetFlowFastBitStringHeap command in SQL Management Studio against the Orion database.
  5. Start the NetFlow service.


SQL server optimization:

  1. Index defragmentation - for more information, click here.
  2. VMWare ESXi 6.0, is know to have an issue impacting the remote Flow Storage database running on FastBit.  Ensure that ESXi600-201509201-UG: Updates esx-base (2124716) is applied on the host of the Flow Storage database. For details, click here.



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