Oracle 11g automated Healthchecks service
Oracle 11g Tips by Burleson Consulting
October 27, 2007
health checks are an integral task for the Oracle DBA and Oracle
11g has introduced a new service and software to assist in
performing health checks.
As of 11g, Oracle Corporation has two
new health check offerings:
- A premium healthchecks service
- A free health monitor using
For a moment, let's suspend Oracle
Technical Support horrible reputation for technical incompetence,
and see if these health checks have any merit.
WARNING: There have
been warnings from the Oracle community that running the healthcheck
service might expose
privacy and licensing issues, prompting Oracle Corporation to
conduct a license audit.
For example, one foreign remote DBA provider says that
full-disclosure with Oracle support might be embarrassing for
companies that are running illegitimate copies of Oracle:
can understand how a person could comfortably conceal the fact
that their test environment runs a binary compatible clone
of a supported operating system, rather than the (much more
expensive) commercial release.
In situations like that, Oracle
Support could (okay, maybe legitimately) deny that person
Let's take a quick look at these
11g automated health check features and wee how they compete with a
Oracle health check by a
At fist glance, neither of these
"health check" tools and services match the comprehensive checks
Oracle monitoring experts, but it's a start, not a replacement
for a human expert, but a step towards automation of health
The heathcheck invokes resource intensive daemon
Oracle Healthchecks premium
The Oracle Healthchecks service
uses Oracle Configuration Manager and is part of a MOSC Premium
Also, the term "Healthchecks" refers only a check of
a small sub-set of potential health issues and focuses solely on a
limited number of configuration issues.
The premium Oracle service says
that it checks little more than basic configuration issues:
"checking top database
configuration issues; checking database host and highlighting
incorrect parameter usage; and recommending improvements in
table and index layout, storage management, table space
allocation, and performance."
"HealthChecks are built from
knowledge gained through resolving customers? most pressing
support problems and from Oracle Support best practices,
providing you with automated recommendations on your
These checks identify potential
issues that may affect the overall stability, performance, and
scalability of your Oracle environment and inform you of the
risks associated with these issues."
Also note some
concerns with using Oracle Configuration Manager.
These relate to the automatic
collection and transmitting of data over a secured connection:
The 11g Health monitor
Oracle also has a free "health
monitor" using the
monitor runs the following checks:
Structure Integrity Check?This
check verifies the integrity of database
files and reports failures if these
files are inaccessible, corrupt or
inconsistent. If the database is in
mount or open mode, this check examines
the log files and data files listed in
the control file. If the database is in
NOMOUNT mode, only the
control file is checked.
check detects disk image block
corruptions such as checksum failures,
head/tail mismatch, and logical
inconsistencies within the block. Most
corruptions can be repaired using Block
Media Recovery. Corrupted block
information is also captured in the
view. This check does not detect
inter-block or inter-segment corruption.
check scans the contents of the redo log
for accessibility and corruption, as
well as the archive logs, if available.
The Redo Integrity Check reports
failures such as archive log or redo
Segment Integrity Check?This
check finds logical undo corruptions.
After locating an undo corruption, this
check uses PMON and SMON to try to
recover the corrupted transaction. If
this recovery fails, then Health Monitor
stores information about the corruption
undo corruptions can be resolved by
forcing a commit.
Transaction Integrity Check?This
check is identical to the Undo Segment
Integrity Check except that it checks
only one specific transaction.
check examines the integrity of core
dictionary objects, such as
col$. It performs the
Verifies the contents of dictionary
entries for each dictionary object.
Performs a cross-row level check,
which verifies that logical
constraints on rows in the
dictionary are enforced.
Performs an object relationship
check, which verifies that
parent-child relationships between
dictionary objects are enforced.
Also, see my notes on 11g health monitoring:
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