IBM Support

IV14524: TCP RETRANSMIT PROCESSING IS VERY SLOW APPLIES TO AIX 6100-08

A fix is available

Obtain the fix for this APAR.

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • The first retransmit packet may be sent after 64 seconds,
so the application will suffer from the slow TCP data
transfer. At that time, the routing entry will show very
high rtt/rttvar value:
.
# route get <ip>
......
recvpipe  sendpipe  ssthresh  rtt,msec    rttvar ...
0         0         0     61847   1058704  ...

Local fix

  • N/A

Problem summary

  • The first retransmit packet may be sent after 64 seconds,
so the application will suffer from the slow TCP data
transfer. At that time, the routing entry will show very
high rtt/rttvar value as below.

 root@skehsn1a # route get 198.18.97.252
   route to: skehnw1a0
destination: 198.18.97.0
       mask: 255.255.255.0
    gateway: 198.18.226.129
  interface: en0
interf addr: skehsn1a0
      flags: <UP,GATEWAY,DONE,STATIC>
 recvpipe  sendpipe  ssthresh  rtt,msec    rttvar hopcount...
       0         0         0     61847   1058704  0

Problem conclusion

  • When customer disables tcp timestamp randomization feature,
Randomized timestamp value is not used for setting
the retransmission timer. This fixes the above mentioned
issue.

Temporary fix

  • 



Comments


    

  • 



APAR Information




    

  • APAR number
    IV14524
    • 

  • Reported component name
    AIX 610 STD EDI
    • 

  • Reported component ID
    5765G6200
    • 

  • Reported release
    610
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Submitted date
    2012-02-01
    • 

  • Closed date
    2012-02-01
    • 

  • Last modified date
    2013-02-26
    • 





    

  • APAR is sysrouted FROM one or more of the following:
    

    
IV13121
    

    • 

  • APAR is sysrouted TO one or more of the following:
    

    • 



Fix information


    

  • Fixed component name
    AIX 610 STD EDI
    • 

  • Fixed component ID
    5765G6200
    • 



Applicable component levels


    

  • R610  PSY  U846293
       UP12/10/23  I  1000
    • 



PTF to Fileset Mapping








      
              
                            

              

              [{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SSMV87","label":"AIX 6.1 Enterprise Edition"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"610","Edition":"","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}},{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSMVAX","label":"AIX Express Edition"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"610","Edition":"","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}},{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SSAUMY","label":"IBM AIX Enterprise Edition"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"610","Edition":"","Line of Business":{"code":"","label":""}},{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SG11Q","label":"AIX 6.1 HIPERS, APARs and Fixes"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"610","Edition":"","Line of Business":{"code":"","label":""}}]
              

                          

          
 
        

      

    

      

        

          

            
Document Information


            

            


                        

            Modified date:
            

            26 February 2013
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
Page Feedback