VTAM V4R2 PTF May Cause APPC Conversation to Stop Responding at Startup (263206)


The information in this article applies to:

  • Microsoft SNA Server 2.11 SP1
  • Microsoft SNA Server 2.11 SP2
  • Microsoft SNA Server 3.0 SP1
  • Microsoft SNA Server 3.0 SP2
  • Microsoft SNA Server 3.0 SP3
  • Microsoft SNA Server 3.0 SP4
  • Microsoft SNA Server 4.0
  • Microsoft SNA Server 4.0 SP1
  • Microsoft SNA Server 4.0 SP2
  • Microsoft SNA Server 4.0 SP3
This article was previously published under Q263206

SYMPTOMS

An APPC or CPI-C application may intermittently stop responding while it waits for a host response. The application stops responding after the Allocate, Send_Data, and Receive_and_Wait (or a CMALLC, CMSEND, and CMRCV for a CPI-C application) commands are issued. A trace shows SNA Server has sent the FMH-5 ATTACH request to the host along with the data, and is waiting for a response. The message that is sent to the host has the change direction indicator (CDI) set.

CAUSE

The FMH-5 ATTACH request and APPC data are sent to the host in two messages (begin-chain and end-chain). A problem in Virtual Telecommunications Access Method (VTAM) V4R2 with IBM PTF #UV60018 prevents the end-chain message from being received by the APPC application on the host.

RESOLUTION

IBM PTF #UV60101 fixes the VTAM problem when it is applied to VTAM V4R2. Contact IBM to request this update.

The third-party products that are discussed in this article are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.

MORE INFORMATION

An SNA Server Node Message shows the following. The first two messages are the begin-chain and end-chain messages that are sent to the host by SNA Server. The third message is the Isolated Pacing Response sent by the host.:

DLC   ----------------------------------------------- 10:51:00.0208
DLC   01020101->04160000 DLC DATA
DLC                      DAF:03 OAF:02 ODAI:on  Normal
DLC                      RQE FMD FI BC DR1 PI BB
DLC
DLC   ---- Header  at address 0131444C, 1 elements ----
DLC   0B080000 1D002E00 03020007 01008A01     <................>
DLC
DLC   ---- Element at address 01D02240, start 10, end 77 ----
DLC   0A918041 0502FF00 03D00000 07E2D8D3     <.j.A.........SQL>
DLC   D7D9D6C4 130802C4 C2F2D3D4 E2C40901     <PROD...DB2LMSD..>
DLC   C4C2F2D9 E4D3C5E2 1A11E4E2 D4C4D5D9     <DB2RULES..USMDNR>
DLC   F0F14BC4 D5D9C4C2 F2F0F107 D045C173     <01KDNRDB201..EAs>
DLC   E5000100                                <V...            >

DLC   ----------------------------------------------- 10:51:00.0208
DLC   01020101->04160000 DLC DATA
DLC                      DAF:03 OAF:02 ODAI:on  Normal
DLC                      RQE FMD EC DR1 CD
DLC
DLC   ---- Header  at address 0131403C, 1 elements ----
DLC   07050000 1D002E00 03020008 01008A01     <................>
DLC
DLC   ---- Element at address 01D02A3C, start 10, end 249 ----
DLC   01902000 68D04100 01006210 41002011     <.. .h.A...b.A. .>
DLC   5E8482F2 82974B85 A7854040 40404040     <^db2bpKexe@@@@@@>
DLC   40404040 40F0F1F8 C1F0F0C6 F8000C11     <@@@@@018A00F8...>
DLC   6D404040 40404040 40001311 5AC4C2F2     <m@@@@@@@@...ZDB2>
DLC   40C39695 958583A3 40F54BF2 00141404     <@Connect@5K2....>
DLC   14030004 14440003 24070006 240F0003     <.....D..$...$...>
DLC   000B1147 D8C4C2F2 61D5E300 85D00100     <...GQDB2aNT.e...>
DLC   02007F20 01001621 10E2D8D3 D7D9D6C4     <..¦ ...!.SQLPROD>
DLC   40404040 40404040 40404000 06210F24     <@@@@@@@@@@@..!.$>
DLC   07000D00 2FD8E3C4 E2D8D3E7 F8F6000C     <..../QTDSQLX86..>
DLC   112EE2D8 D3F0F5F0 F2F0003C 210437E2     <..SQL05020.<!.7S>
DLC   D8D3F0F5 F0F2F0D5 E3404040 40404040     <QL05020NT@@@@@@@>
DLC   40404040 40404040 408482F2 82974B85     <@@@@@@@@@db2bpKe>
DLC   A7854040 40404040 40404040 40C4C2F2     <xe@@@@@@@@@@@DB2>
DLC   D3D4E2C4 4000000A 00350006 119C04E4     <LMSD@....5.....U>

----------------------------------------------- 10:51:00.0224
04160000->01020101 DLC DATA
                   DAF:02 OAF:03 ODAI:on  Normal
                   +RSP FMD BC EC PI

---- Header  at address 01314070, 1 elements ----
04080004 1D002E00 02030000 0100C401     <..............D.>

---- Element at address 01D02A3C, start 10, end 12 ----
830100                                  <c..             >

Neither the end-chain message or the Isolated Pacing Response appear in a VTAM trace. Note that because this session is using two-stage pacing, the Isolated Pacing Response is generated by a boundary function, which is why it does not appear in the VTAM trace.

Modification Type:MinorLast Reviewed:7/15/2004
Keywords:kbprb KB263206
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