3059886 - BCP OUT and SELECTs hang with status 'send sleep' or application not starting - SAP ASE 16.0 on AIX 7.2 TL5 SP2

• After upgrading AIX to the patch 7200-05-02-2114 from the patch 7200-05-01-2038 or upgrading AIX from 7.1 to 7.2.
• There is no issue in ASE running on AIX at the 7.2.5.1.2038 patch level. 
• Processes get the status "send sleep" that never clears. 
• These processes may run BCP OUTs or SELECTs. The same issue was also observed when the process ran "sp_sysmon diskio".
• "dbcc stacktrace" for the process running BCP OUT shows the following functions:

upsleepgeneric()
ussflush()
sendbuffer()
sendhost()
sendichars()
LeSendRow::_sendColsToClient()
LeSendRow::sendRowToClient()
LeEmitSndOp::_LeOpNext()
LePlanNext+0x190()
exec_lava()
s_execute()
sequencer()
execproc()
s_execute()
sequencer()
tdsrecv_language()

• "procstack" for the process running a SELECT via ISQL shows the following calls:

__fd_poll(??, ??, ??) + 0xb4
poll(??, ??, ??) + 0xc
sybnet__complete_io(??, ??, ??) + 0x2e4
sybnet_read(??, ??, ??, ??, ??, ??, ??) + 0x194
np_io_read(??, ??, ??, ??) + 0x450
ct__tds_recvpkt(??, ??, ??) + 0x134
ct__tds_get_bytes(??, ??, ??, ??) + 0x430
ct__tds_fetchcols(??, ??, ??) + 0x69c
ct__tds_readrow(??, ??, ??) + 0x4c0
ct__tds_readfetch(??, ??, ??) + 0x480
ct_tds_fetch(??) + 0x80
ct__api_fetch(??, ??, ??) + 0xb0

• The monProcessNetIO.NetworkPacketSent counts for these processes are not increasing.
• These processes can be killed using the regular 'kill' command.
• Rebooting the ASE server doesn't help.
• For Business Suite applications (java or abap stack) connect via R3load, sybctrl or even isql is not possible. All connects may receive a timeout.
• Also in Business Suite can be seen the process or during SWPM install we see hang install similar to : dipgntab -rwr40 -srctt DDNTT -srctf DDNTF -ds

• SAP Adaptive Server Enterprise (ASE) 16.0 
• AIX 7.2 with patch 7200-05-02-2114 (7.2 TL5 SP2)

IOCP, packet, socket, IBM, iocpdebug, ifix , KBA , BC-SYB-ASE , Sybase ASE Database Platform (non Business Suite) , BC-DB-SYB , Business Suite on Adaptive Server Enterprise , BC-OP-AIX , IBM AIX , Problem