Enabling xplink in the runtime environment and compiling applications
with xplink enabled improves performance in z/OS V1R2.
- For best performance, use the LPALSTxx parmlib member to ensure that LE
and C++ runtimes are loaded into LPA, as shown in the following example:
Example:
sys1.parmlib(LPALSTxx):
********************************* Top of Data ********************
USER.LPALIB,
ISF.SISFLPA, SDSF
CEE.SCEELPA,
LANGUAGE ENVIRONMENT
CBC.SCLBDLL, C++ RUNTIME
.
.
.
******************************** Bottom of Data ******************
- Ensure that the Language Environment data sets, SCEERUN and SCEERUN2,
are authorized to enable xplink.
Processes that run
the client ORB, since they start the JVM, must run with xplink(on). For best
performance in the xplink runtime, compile applications that use JNI services
with xplink enabled. Enabling xplink in the runtime environment and compiling
applications with xplink enabled improves performance in z/OS V1R2. As you
move from z/OS V1R2 to z/OS V2R6 you should experience additional performance
improvements when all the LE services WebSphere calls are xplink enabled.
Not all native code in WebSphere Application Server for z/OS or companion
products such as DB2 or MQ are xplink enabled and this is an area of active
investigation.
- Ensure that you are NOT using the following options during production:
- RPTSTG(ON)
- RPTOPTS(ON)
- HEAPCHK(ON)
- Turn LE heappools on.
If you are running a client on z/OS, setting the
following: SET LEPARM='HEAPP(ON)' in a shell script, turns
on LE heappools, which should improve the performance of the client.
- Refer to Fine tuning the LE heap
Customization Note: Do not modify LE parameters
without consulting IBM support. The LE parameters are set internally to ensure
the best possible performance of the WebSphere Application Server, which is
the main LE application running in the address space. If you need to add or
change LE parameters, make sure that you work with the IBM WebSphere support
team to ensure that the internally set parameters are not compromised. The
appropriate interface for making these changes is through the PARM= parameter
of the EXEC PGM=BBOSR statement in the startup JCL.