Server Jobs Performance Very Slow post Infosphere Upgrade

[nvalia]

Comparing the uvConfig Files on both Versions, I see the following differences between the 2 versions

Is it OK to change these configuration values or we need to contact IBM Support?

If we do change these in 9.1, do we have to Restart Datastage for these configuration changes to take effect?


v9.1 v7.5 Comment
MFILES 200 150
T30FILE 512 200
RLTABSZ 300 75
MAXRLOCK 299 74
NLSMODE 1 NA No NLS Setting in v7.5


# MFILES - specifies the size of the
# rotating file pool. The value of
# MFILES should be set to a value
# no greater than the kernels
# per process open file limit less the
# sum of the maximum number of named
# pipes opened by a user application
# and the 8 files reserved for internal
# use.

# T30FILE - specifies the number of
# dynamic files that may be opened.
# Used to allocate shared memory
# concurrency control headers.

# RLTABSZ - sets the number of read lock entries
# (both exclusive, READU, and shared, READL) in a
# group lock semaphore set. Great care should be
# exercised when changing this parameter. The
# performance of the disk i/o subsystem may be
# profoundly affected.

# MAXRLOCK - This defines the number of record locks which
# may be obtained against one file in an SQL transaction
# before the lock manager escalates the locking strategy
# to obtain a file lock. This value cannot be greater
# then RLTABSZ - 1.

# NLSMODE - Set to 1 if NLS mode is ON for the
# system as a whole. 0 means that NLS mode is OFF.

[ray.wurlod]

There's no real reason to change anything in uvconfig. It won't help.

There are two reasons for slower performance, and you can't do much about either of them.

• You're now using NLS, which means you're potentially processing more than one byte per character. Internally, with NLS enabled, DataStage uses an idiosyncratic UTF-8 encoding in server jobs, which can mean up to four bytes for some characters. So, at the very least, you're probably processing more bytes than before, even for the "same" data.
  
  Server jobs need to establish an interface with the Information Server Framework, which involves translations between the data-type-free environment of server jobs and the strictly-typed environment of ISF. This, too, comes at a cost.

[nvalia]

Ray,

We are OK to turn NLS Off..So does setting this parameter in the UVCOnfig NLSMODE to '0' from the current '1' help in reducing the performance degradation impact?

Also if we do change this setting, a Restart of the Datastage Engine would be required ?

[ray.wurlod]

It makes (will make) no difference. The choice of supporting NLS at installation is what drives the internal storage of characters, not the value of the NLSMODE parameter in uvconfig.

If you do change NLS mode a restart is required. However, it will make almost no difference to performance of server jobs.

[qt_ky]

To answer one question, after changing uvconfig, you would have to uvregen it and restart before changes would take effect.

Another idea is to check whether or not applying fix pack 2 would include anything to help your performance or not. I doubt it would.

The NLS difference is a good find. I thought that the NLS setting was an install-time only decision. See what others say and/or contact Support.

[chulett]

I thought that the NLS setting was an install-time only decision. See what others say and/or contact Support.

It basically is... see Ray's simul-post.