Conference azur::mcc

3553.0. "Error in MCC_SEND_EVENT for ULTRIX data collector" by MANWRK::BLOWER () Thu Aug 13 1992 05:56

    In running some performance tests on DECmcc for ULTRIX using the Data
    Collector we have found a feature. When using the mcc_send_event
    routine there is a wait of 5 seconds before the link is disconnected.
    
    In the mcc_send_event there is the following
    
           case 4 :       /* disconnect logical link */ 
              sleep(wait_sec); /* 6-nov-1991 until a better way */
              switch (*pI_protocol)
    		{
                .....
                }
    This presumably is to stop the lik from going down before the listner
    receives the data packet.
    
    A better way is the following. 
    
    in  mcc_dna_dna_connect() routine do the following.
    
    where the socket is created :-
    
    
       sock_d = socket(AF_DECnet,SOCK_STREAM,0);
       if ( sock_d < 0 )
          {
          /* error */
          }
       else 
           { /* success */
           
           setsockopt( sock_d, 
    		       SOL_SOCKET, 
    		       SO_LINGER, 
                       (char *) linger,
                       sizeof(linger) );
           ....
           ....
           }
    
    The SO_LINGER controls actions on unsent messages when a close is sent.
    If SO_LINGER is set then the system will block until all data has been
    received by the remote system or the linger timout expires.
    
    Linger is the linger structure specified in socket(2) manpage
    
    
    Hope this helps.
    
    
    Graham Blower
    

    Graham,
    
    	Thanks for your input.  The issue has been discussed recently and
    alternatives are being searched.  We hope to improve its performance
    in future release too.
                       
    	Jean