Supporting Hardware - Expert Consolidation in Oracle Database 12c - page 102

Benchmarking Storage with SLOB
The SLOB kit allows you to run three different benchmarks, according to the documentation. Unlike the previously
introduced benchmarks, which focused on physical I/O, SLOB also allows you to check how well your architecture
can deal with logical I/O. The test cases are categorized in the documentation into focus areas:
Physical I/O on Oracle data files. For this test you need a small buffer cache, ideally less
than 100 MB. The test is useful to see how well your storage subsystem is attached to the
server and how much physical I/O it can provide.
Logical I/O test. This test case requires a large SGA and especially a large buffer cache.
It tests how well your architecture can scale logical I/O. If you think of today's multi-socket
systems with their complex memory arrangements in form of level 1, level 2, last-level
cache, DRAM remotely and locally attached, then this test suddenly starts to make a lot
of sense.
The final test is about redo. Like the previous LIO test, it too requires a large SGA, in such a
way that the database writer processes do not have to flush dirty buffers to disk.
Controlling SLOB
Unlike the initial release of the software, SLOB 2 is controlled slightly differently, by means of a configuration file.
The slob.conf file controls the aspects of the benchmark such as allowed levels of concurrency as well as the ratio
between reads and writes. In the initial SLOB release, you needed to call the main benchmark script-runit.sh-with
two parameters. One indicated the number of readers and the other the number of writers. Concurrency was not
permitted. SLOB 2 uses a configuration file to define the characteristics of a given benchmark execution. A sample file
is shown here:
[oracle@server1 SLOB]$ cat slob.conf
UPDATE_PCT=0
RUN_TIME=60
WORK_LOOP=0
SCALE=10000
WORK_UNIT=256
REDO_STRESS=HEAVY
LOAD_PARALLEL_DEGREE=12
SHARED_DATA_MODULUS=0
# Settings for SQL*Net connectivity:
#ADMIN_SQLNET_SERVICE=slob
#SQLNET_SERVICE_BASE=slob
#SQLNET_SERVICE_MAX=2
#SYSDBA_PASSWD="change_on_install"
export UPDATE_PCT RUN_TIME WORK_LOOP SCALE WORK_UNIT LOAD_PARALLEL_DEGREE REDO_STRESS SHARED_DATA_
MODULUS
[oracle@server1 SLOB]$