Kevin Closson's Blog: Platforms, Databases and Storage

This is a hasty blog post to get SLOB 2.2 out to those who are interested.

Where To Get The Kit

Please visit kevinclosson.net/slob

About The New Kit

In addition to doing away with the cumbersome “seed” table and procedure.sql, this kit introduces 5 new slob.conf parameters. By default these parameters are disabled.

This SLOB distribution does not require re-executing setup.sh. One can simply adopt the kit and use it to test existing SLOB databases. The following explains the new slob.conf parameters:

DO_UPDATE_HOTSPOT=FALSE

When set to TRUE, modify SQL will no longer affect random rows spanning each session’s schema. Instead, each session will only modify HOTSPOT_PCT percent of their data.

HOTSPOT_PCT=10

This parameter controls how much of each session’s schema gets modified when UPDATE_PCT is non-zero. The default will limit the scope of each session’s data modifications to a maximum of 10% of their data.

THINK_TM_MODULUS=0

When set to non-zero this is a frequency control on how often sessions will incur think time. For example, if set to 7, every seventh SQL statement will be following by a sleep (think time) for a random amount of time between THINK_TM_MIN and THINK_TM_MAX. It’s best to assign a prime number to THINK_TM_MODULUS.

THINK_TM_MIN=.1

The low-bound for selection of a random period to sleep when THINK_TM_MODULUS triggers a think time event.

THINK_TM_MAX=.5

The high-bound for selection of a random period to sleep when THINK_TM_MODULUS triggers a think time event.

Notes About Think Time

The resolution supported for think time is seconds and values in the hundreds of seconds are supported.

Additional Helpful Files

The additional tarball (at the following link) has a slob.conf, simple.ora and awr.txt that show a way to have 256 sessions produce the following load profile (on 2s16c32t E5 Xeon):

https://my.syncplicity.com/share/geydubw3q42okrt/think-time-help-files.tar