[RESOLVED] Server Not Responding Issue

[dw85745]

I'm getting data from a Server over which I have no control.
Sometimes it does not respond and the code I'm using causes the App to freeze.
Only thing I can think of maybe setting a timer in my program such that if a certain period of time expires
I exit my Sub that called the Server.

UPDATE: Changed to Timer and dropped Sleep (forgot it suspends execution)

Still looking for better alternative.

           'Wait Until Server Returns Records
            'or Kill if Error
            Do
               If (mstrGotRecords = "error") Then
                  frmHD.Caption = "ERROR - Check and Redo Request"
                  Exit Sub
               Else
                  If (mstrGotRecords = "fin") Then
                      Exit Do
                  Else
                       Call fWait(3)      'API function
'>>>
                  End If
               End If
            Loop

Any other solution appreciated.

[Niya]

What kind of server is it that you're communicating with ?

[dw85745]

Good Question:

I all know is they're running Java and provide an API to access it.

[Niya]

Ok...So I assume its a local server ? How is communication to it achieved ? TCP/IP ? Pipes ? Dlls ?

[Max187Boucher]

With a loop which i do not recommend,

Something like this should work

    Do Until mstrgotrecords = "fin"
      DoEvents
        If (mstrgotrecords = "error") Then
          frmhd.Caption = "ERROR - Check and Redo Request"
          Exit Sub
        End If
    Loop

The way I would do it is with a timer.

Private Timer_Seconds As Integer
Private Timer_TimeOut As Integer

Private Sub RequestRecord(WaitDelay As Integer, Optional TimeOut As Integer = -1)
  Timer_Seconds = 0
  Timer_TimeOut = TimeOut
  Timer1.Interval = WaitDelay
  Timer1.Enabled = True
End Sub

Private Sub Timer1_Timer()
  Select Case LCase(mstrgotrecords)
  
    Case "error"
      frmhd.Caption = "ERROR - Check and Redo Request"
             
    Case "fin"
      frmhd.Caption = "FOUND"
     
    Case Else
      If TimeOut_Seconds = Timer_Seconds Then
        frmhd.Caption "TIMEOUT - Check and Redo Request"
      Else
        Timer_Seconds = Timer_Seconds + 1
        Exit Sub
      End If
           
  End Select
  Timer1.Enabled = False
End Sub


Private Sub Command1_Click()
RequestRecord 2       'No Timeout, timer will keep going!
'RequestRecord 2, 30  'Timeout after 30 seconds, timer stop after 30 seconds!
End Sub

Edit:
Not sure if once it hits the last "record" and it shows "fin", if so, then forget the timer and use the loop.

[dw85745]

Thanks both for input:

Niya: Yes it is TCP/IP and remote with another firm.

Max187Boucher:

Yes, you are correct -- the final record is tagged with "fin".
Your first example (loop) basically mirrors mine in that if a final record is received ('fin") or the Server sends some kind of error message I can get out of the loop.
However, if the Server never responds to my request, or hangs then timer only "OUT" I see.
Appreciate you second code -- IMHO, better logic approach

---------------------------------
You might want to look at: 'Source: MSDN Q231298
API Timer and IMHO easier to use than VB's

[dw85745]

Update:

For those with "Loop Exit" concerns, you might want to check out
API-Guide "Wait Message" example.
Only thing that appears to work in VB's single thread environment without
resorting to a Background Thread or possibly ActiveX