Topic
  • 6 replies
  • Latest Post - ‏2013-08-20T14:05:58Z by markevans
huub100759
huub100759
48 Posts

Pinned topic Dropping JAVA400 connection on Tomcat

‏2013-08-09T07:37:44Z |

I, m experiencing a strange problem.

2 weeks ago we moved the tomcat implementation from a Windows 2003 to a Windows 2008 server. No changes (except IP-address) were made.

I m using the Jt400.jar for connection. It allways has worked fine , but since the move , the JAVA400connection drops . If the user restarts the application it works again.

But i noticed that the QZDASOINIT job on the iSeries (V5R4) ended abnormally  :

A connection with a remote socket was reset by that socket.
Host server communications error occurred on recv() - length.
Er is een fout opgetreden in de i5/OS-databaseserver. Foutcode 2.

(im not sure if that happened too in the old configuration)

Anyone any ideas where i should start looking??

Thanks in advance

Huub Keulartz

QNH Consulting Zuid

  • markevans
    markevans
    3034 Posts

    Re: Dropping JAVA400 connection on Tomcat

    ‏2013-08-19T14:33:50Z  

    Huub,

    I have not seen this before.

    A couple of questions (probably obvious).

    a.)  Any changes in the datasource definitions in Tomcat between the two implementations>

    b.) Any changes to the applications?..

    Also, found this when I googled the "host server communications error occurred...." message, but this message seems to be rather generic.  Have you looked up the actual message associated with "Er is een fout opgetreden in de i5/OS-databaseserver. Foutcode 2"

    Not Enough Prestart Jobs at Server

    If the number of prestart jobs associated with the TCP/IP server is limited by the QRWTSRVR prestart job entry of the QSYSWRK subsystem, and all prestart jobs are being used for a connection, an attempt at a new connection will fail with the following messages:

    CPE3426
    A connection with a remote socket was reset by that socket.
    CPD3E34
    DDM TCP/IP communications error occurred on recv() - MSG_PEEK.

    You can avoid this problem at the server by setting the MAXJOBS parameter of the Change Prestart Job Entry (CHGPJE) command for the QTWTSRVR entry to a higher number or to *NOMAX, and by setting the ADLJOBS parameter to something other than 0.

     

     


     

  • huub100759
    huub100759
    48 Posts

    Re: Dropping JAVA400 connection on Tomcat

    ‏2013-08-20T07:05:56Z  
    • markevans
    • ‏2013-08-19T14:33:50Z

    Huub,

    I have not seen this before.

    A couple of questions (probably obvious).

    a.)  Any changes in the datasource definitions in Tomcat between the two implementations>

    b.) Any changes to the applications?..

    Also, found this when I googled the "host server communications error occurred...." message, but this message seems to be rather generic.  Have you looked up the actual message associated with "Er is een fout opgetreden in de i5/OS-databaseserver. Foutcode 2"

    Not Enough Prestart Jobs at Server

    If the number of prestart jobs associated with the TCP/IP server is limited by the QRWTSRVR prestart job entry of the QSYSWRK subsystem, and all prestart jobs are being used for a connection, an attempt at a new connection will fail with the following messages:

    CPE3426
    A connection with a remote socket was reset by that socket.
    CPD3E34
    DDM TCP/IP communications error occurred on recv() - MSG_PEEK.

    You can avoid this problem at the server by setting the MAXJOBS parameter of the Change Prestart Job Entry (CHGPJE) command for the QTWTSRVR entry to a higher number or to *NOMAX, and by setting the ADLJOBS parameter to something other than 0.

     

     


     

    Hi Mark

     

    Thanks a lot for taking the time to look at my problem.

    There were no changes.

    And i allready checked out the QUSRWRK settings etc.

    But i noticed something weird.

    When i checked the older joblogs from QZDASOINIT jobs (when i was using  the 2003 server), i also saw that errormessage occur, but it had no influence  on the running applications.

    In the new situation I get a  SQl exception (that the connection could not be made) in the EGL-application.

    The only difference  between the 2 servers is that the old one is Windows 2003 and the new one 2008 R2.

    Both with the same JRE.

     

    I am out of answers...

    Huub

  • clogs
    clogs
    186 Posts

    Re: Dropping JAVA400 connection on Tomcat

    ‏2013-08-20T10:35:45Z  

    Hi Mark

     

    Thanks a lot for taking the time to look at my problem.

    There were no changes.

    And i allready checked out the QUSRWRK settings etc.

    But i noticed something weird.

    When i checked the older joblogs from QZDASOINIT jobs (when i was using  the 2003 server), i also saw that errormessage occur, but it had no influence  on the running applications.

    In the new situation I get a  SQl exception (that the connection could not be made) in the EGL-application.

    The only difference  between the 2 servers is that the old one is Windows 2003 and the new one 2008 R2.

    Both with the same JRE.

     

    I am out of answers...

    Huub

    Hi Huub,

    Is it maybe because Windows Server 2008 R2 supports IPv6. We had some connection problems here because of that until we switched off IPv6 support on the server.

    Willem

  • huub100759
    huub100759
    48 Posts

    Re: Dropping JAVA400 connection on Tomcat

    ‏2013-08-20T10:59:29Z  
    • clogs
    • ‏2013-08-20T10:35:45Z

    Hi Huub,

    Is it maybe because Windows Server 2008 R2 supports IPv6. We had some connection problems here because of that until we switched off IPv6 support on the server.

    Willem

    Hi Willem

     

    Thank you for you reaction.

    Were those problems of a constant nature or did they occur now and then?

     

    Huub

  • clogs
    clogs
    186 Posts

    Re: Dropping JAVA400 connection on Tomcat

    ‏2013-08-20T11:24:17Z  

    Hi Willem

     

    Thank you for you reaction.

    Were those problems of a constant nature or did they occur now and then?

     

    Huub

    Hi Huub,

    I think those problems were of a constant nature, but you can always try and see if it rectifies the problems you are experiencing.

    Regards,

    Willem

  • markevans
    markevans
    3034 Posts

    Re: Dropping JAVA400 connection on Tomcat

    ‏2013-08-20T14:05:58Z  
    • clogs
    • ‏2013-08-20T11:24:17Z

    Hi Huub,

    I think those problems were of a constant nature, but you can always try and see if it rectifies the problems you are experiencing.

    Regards,

    Willem

    If Willem's suggestion does not resolve it..I would suggest you open a PMR with the Db2 teams on i5/os or WAS folks.  Maybe they would have a suggestion.  I would think the DB2 team would be the most help.