DB2 CONNECT / DB2CONNCT / B50 - DB2

When timerLevelForQueryTimeOut =2 is set either explicitly or by
default and connection between JCC driver and server fails due
to network problem ( e.g -4499), Timer threads created for each
connection is not closed. This leads to build up of timer
objects from JCC and can lead to to java.lang.OutOfMemoryError
due to memory consumption from heap. This condition is also
dependent on the number of threads available for use in the
process which is the process limit for pthreads setting in the
MAXTHREADS.
In the javacore, you could see as below:
Dump Event "systhrow" (00040000) Detail
"java/lang/OutOfMemoryError" "Failed to create a thread: retVal
-1073741830, errno 112 (0x70), errno2 0xb51025d" received
3XEHSTTYPE 09:38:44:092511515 GMT j9vm.533 - startJavaThread
omrthread_create failed: retVal=-1073741830 Thread create
failed, os_errno=112 (0x70), os_errno2=189858397 (0xb51025d)
3XEHSTTYPE 09:38:44:093167166 GMT j9vm.302 -
>setCurrentExceptionUTF exceptionNumber=16777227
detailUTF=Failed to create a thread: retVal -1073741830, errno
112 (0x70), errno2 0xb51025d
From the error codes:
112 0070 EAGAIN The resource is temporarily unavailable.
025D JRTooManyThds
An attempt was made to create another thread but the process
limit for pthreads has already been reached.
Action: Try the request again after some threads have been
exited and detached or increase the process thread limit.
The above problem occurs due to JCC timer threads not getting
closed for connections receiving -4499 errors. This problem can
be seen if you have too many broken connections that may arise
due to closing and reopening the DDF component of DB2 z / OS.
There may be other scenarios that can lead to -4499 errors along
with the DDF restart.

****************************************************************
* USERS AFFECTED:                                              *
* Db2 Connect users                                            *
****************************************************************
* PROBLEM DESCRIPTION:                                         *
* See Error Description                                        *
****************************************************************
* RECOMMENDATION:                                              *
* Fix available in Jcc 4.31 (V11.5 M7 FP0 JDBC & SQLJ) onwards *
****************************************************************

set timerLevelForQueryTimeOut=-1

****************************************************************
* USERS AFFECTED:                                              *
* Db2 Connect users                                            *
****************************************************************
* PROBLEM DESCRIPTION:                                         *
* See Error Description                                        *
****************************************************************
* RECOMMENDATION:                                              *
* Fix available in Jcc 4.31 (V11.5 M7 FP0 JDBC & SQLJ) onwards *
****************************************************************

Fix available in Jcc 4.31 (V11.5 M7 FP0 JDBC & SQLJ) onwards

Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :

02.09.2021
30.11.2021
24.10.2022