Db2 CLP uses two independent processes, frontend process and
backend process. Both processes use IPC queues to communicate
with each other. On Unix and Linux operating systems, it is
possible that duplicate IPC queue ids to get generated for
different frontend agents, thus causing various symptoms.
Possible symptoms include:
1. Intermittent errors returned to CLP. For example you may
observe the following error messages :
DB21016E The Command Line Processor encountered a system error
while sending the command to the backend process.
DB21018E A system error occurred. The command line processor
could not continue processing.
In addition, following messages may be logged in the
db2diag.log file:
2018-08-05-09.00.11.071950-300 E146642A659 LEVEL: Error
(OS)
PID : 27590832 TID : 1 PROC : db2
INSTANCE: db2inst NODE : 000
HOSTNAME: hostname
EDUID : 1
FUNCTION: DB2 UDB, oper system services, sqlowqueInternal,
probe:40
MESSAGE : ZRC=0x870F00BB=-2029059909=SQLO_QUE_NO_ACCESS
"do not have the access right"
CALLED : OS, -, msgsnd
OSERR : EACCES (13) "The file access permissions do not allow
the specified action."
DATA #1 : system V message queue identifier.,
PD_TYPE_SYSV_QUEUE_ID, 4 bytes
0x29F000AA
DATA #2 : Pointer, 8 bytes
0x09001000a198c1e0
DATA #3 : unsigned integer, 8 bytes
4176
2. Script fails with SQLSTATE 42702 / SQLCODE: -204
3. 2 or more frontends use the same backend process, and script
could cause unexpected data updates or return unexpected
results.
1 could occur if CLP frontend processes were started by
different user IDs.
2 and 3 could occur if CLP frontend processes were started by
the same user ID.
These issues have been treated with APARs such as IT22632 (fixed
in 11.1 Mod2 Fix Pack2 iFix002) and IT23909 (fixed in 11.1 Mod4
Fix Pack4 for non-AIX platforms), but they did not completely
resolve these issues.
This APAR will be able to avoid issue 3 completely. |
