Oracle sql version is 19c. I have encountered one issue that Oracle sql sometime will disconnect and then auto connect. How can I find the cause?

To get error, so write below.

try { OracleConnection } catch (exception ex) { ex.getMessage() }

Oracle returns below error

Oracle.DataAccess.Client.OracleException (0x80004005): ORA-03135: connection lost contact\
Process ID: 7156\
Session ID: 653 Serial number: 32099\
   at Oracle.DataAccess.Client.OracleException.HandleErrorHelper(Int32 errCode, OracleConnection conn, IntPtr opsErrCtx, OpoSqlValCtx* pOpoSqlValCtx, Object src, String procedure, Boolean bCheck, Int32 isRecoverable, OracleLogicalTransaction m_OracleLogicalTransaction)\
   at Oracle.DataAccess.Client.OracleException.HandleError(Int32 errCode, OracleConnection conn, String procedure, IntPtr opsErrCtx, OpoSqlValCtx* pOpoSqlValCtx, Object src, Boolean bCheck, OracleLogicalTransaction m_OracleLogicalTransaction)\
   at Oracle.DataAccess.Client.OracleCommand.ExecuteReader(Boolean requery, Boolean fillRequest, CommandBehavior behavior)\
   at Oracle.DataAccess.Client.OracleCommand.ExecuteReader()\
   at _Default.Login(Object sender, EventArgs e) in c:\inetpub\wwwroot\testing\login.aspx.cs:line 82

What is the cause for "ORA-03135: connection lost contact"? How can I solve it?

  • The database session is most likely timing out for some reason, or possibly (if the session wasn't idle) some processing in the session caused the dedicated server process for the session to crash. Check the database alert log, the sqlnet.ora timeout parameters, or the user profile timeout parameters in the database.
    – pmdba
    Commented Nov 21, 2023 at 18:55
  • can i know how to find database alert log? got added timeout parameters in sqlnet.ora. idle_time with connect_time is unlimited in oracle database. the disconnection issue still existing.
    – Jun
    Commented Nov 23, 2023 at 4:52


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