Oracle Essentials [Electronic resources] : Oracle Database 10g, 3rd Edition نسخه متنی

5.1 Management and Enterprise Manager

Each version of Oracle contains a new set of features that require
corresponding management capabilities. This ever-increasing feature
curve previously required a fairly steep learning curve on the part
of the novice. Over the past few releases, Oracle has made more
database features self-tuning and self-managing. Oracle Database 10g
and its "Intelligent
Infrastructure" is a huge step forward in this
effort. Many manual steps needed to manage releases previous to
Oracle Database 10g have been eliminated. Management of this
infrastructure is accomplished through the self-managing capabilities
of the database and through the Oracle Enterprise Manager 10g.

EM can now manage not only multiple Oracle databases, but also the
Oracle Application Server, E-Business Suite, and Collaboration Suite.
However, as we've mentioned, our primary focus in
this book is on Oracle's database management
capabilities.

5.1.1 Oracle Enterprise Manager Architecture

Oracle
first distributed the Oracle Enterprise Manager with database
packaging in Oracle7. Initial EM versions required Windows-based
workstations as client machines. A browser-based EM console built
using Java appeared with the Oracle8i database
release. The HTML-based console first appeared with Oracle9
iAS and is now included as Enterprise Manager
10g with the database in Oracle Database 10g.
Enterprise Manager 10g can be used for management tasks locally,
remotely, and/or through firewalls. Individual consoles can manage
single databases or multiple databases. Where EM is used to manage
Oracle deployed on a grid of computers, or to manage multiple Oracle
database instances and products, it is installed using a Grid Control
Enterprise Manager CD.

EM is composed of the following components:

Oracle Management Agents

These agents monitor databases and services on the local and remote
nodes. An agent can both monitor the database and services on a
remote node and communicate the results of this monitoring back to
EM.

Central Console

The console allows you to view the status of database components.

Oracle Management Service (OMS)

This service, located in the Oracle Application Server, is deployed
as an OC4J (Oracle Application Server Containers for J2EE)
application and renders the HTML user interface.

Management Knowledge Center (MKC) / Management Repository

This is the central repository of enterprise-wide management data,
including hardware and software configuration data leveraged in
lifecycle, cloning, and patch management.

The EM architecture is shown in Figure 5-1.

Figure 5-1. Oracle Enterprise Manager architecture

Management Agents are available for the
wide variety of operating systems on which the Oracle database is
available and are responsible for automatic service discovery, event
monitoring, and job (predefined task) execution. Management Agents
can also send Simple Network Management Protocol (SNMP) traps to
database performance monitors in tools such as CA Unicenter Network
and Systems Management, the HP OpenView Operations console, and IBM
Tivoli. Through the agents, EM can be used to manage Oracle databases
running on Unix, Linux, Windows, and many other operating systems.

5.1.2 Oracle Enterprise Manager Consoles

The growth
in deployment within single companies of Oracle on Windows, Linux,
and Unix has resulted in growing popularity of the EM interface to
manage Oracle instances residing on a mixture of operating systems.
The Enterprise Manager 10g initially shipping with Oracle Database
10g provides HTML-based and Java-based consoles.
(We'll describe the functionality provided by each
later on.) These provide a common interface for management across
multiple platforms and a framework that supports a variety of
monitoring tools. The HTML console will include more and more
functionality over time, including much of what is initially only in
the Java console.

The Enterprise
Manager 10g interface and framework are used for monitoring and
managing events, jobs, new database self-monitoring features,
reports, roles and privileges, and audit trails. An EM console and
the underlying Intelligent Infrastructure (described in a subsequent
section) are installed as part of the normal Oracle Database 10g
database installation process. Much of the functionality in previous
Enterprise Manager optional packs, such as diagnostics and tuning,
performance, and change management, are now included in EM and are
built upon the new infrastructure. EM automatically discovers target
databases as soon as it is installed.

The HTML console can manage many database tasks and components,
including backup and recovery, export and import, instances, Real
Application Clusters (RAC), schema, security (users and roles), the
OLAP option, and Data Guard. Included is
iSQL*Plus, a new browser-based version of
SQL*Plus. The Java console enables additional
management of Advanced Queues, instances, replication, HTML DB,
schema, security, the Spatial Option, storage, Streams, workspace,
Fail Safe, LogMiner, and Text. Both also provide SQL Scratchpads, the
SQL*Plus worksheet, and management of the OLAP Option and
materialized views (Summary Advisor).

Most network and database connectivity management is available in the
Java console, although the HTML console now provides some Oracle Net
administration. Advanced security management is also through the Java
console, including the Enterprise Security Manager, Wallet Manager,
Policy Manager, and Directory Manager.

Additional
functionality is provided in options (sometimes called packs) to
Enterprise Manager in the areas of diagnostics, tuning, change
management, and configuration management. The following options are
now fully integrated into the EM console and are built upon the new
management infrastructure:

Database Diagnostics option

This option, which monitors databases on single systems and across
systems, aids in identifying performance bottlenecks and providing
tools for problem resolution.

Application Server Diagnostics option

This option enables the monitoring of an application that has been
deployed using the middle-tier Application Server for availability
and overall response.

Database Tuning option

This option provides recommendations for improving transaction and
query performance.

Database Change Management option

This option is used in the evaluation and implementation of database
schema changes.

Database Configuration Management optionApplication Server Configuration option

These options are used to track operating systems and associated
hardware, as well as software installations and patches. They also
provide automated replication and patching.

Finally, the HTML console also contains wireless-enabled features and
can be used for management of the Oracle Application Server,
including real-time and historical performance monitoring, events
monitoring and statistics, J2EE diagnostics, unified Application
Server management, application deployment, and cluster management.

A simple management interface is also deployable through the Oracle
Application Server Portal. Five management portlets are prepackaged
for use with the Portal, providing displays of target summaries,
outstanding alerts (notifications where thresholds are reached or
exceeded), metric details, availability timelines, and executive
summary information.

5.1.3 The HTML Console Interface

Let's have a closer
look at managing Oracle through the HTML console that is available as
part of a normal Oracle Database 10g instance installation. Logging
into Enterprise Manager brings you to the home page of your database
(see Figure 5-2). Four tabs are shown to provide
quick EM navigation: a home tab (your initial location), an
administration tab, a maintenance tab, and a performance tab. At the
top of the console page, there are also links to setup (for setting
up and managing additional administrators, notification methods,
etc.), preferences (e.g., notification schedules), help, and logout.
The following describe what you'll see in each of
the tabbed areas:

Home Page

The Home Page is segmented into the
following areas: general characteristics (e.g., status, instance
name, version, host, listener names, and Oracle home), host CPU,
active sessions, space usage, advise (a link to the Automatic
Database Diagnostic Monitor (ADDM) findings, which are described
later in this chapter), high availability (instance recovery time and
archiving status), activity summary of scheduled and running jobs,
and related alerts. The page also includes related links to Advisor
Central, all metrics, manage metrics, iSQL*Plus,
alert history, blackouts (periods during which data collection
activities are suspended), metric collection errors, alert log
content, jobs, and configuration monitoring.

Administration Page

The Administration Page has links to instance
administration (initialization parameters, undo management, and
memory parameters), storage administration (control files,
tablespaces, datafiles, rollback segments, redo log groups, archive
logs, and temporary tablespace groups), security administration
(user, roles, and profiles), the database resource manager (resource
monitors, consumer groups, and plans), the scheduler (jobs,
schedules, programs, job classes, windows, and window groups), data
warehouse administration (OLAP cubes, dimensions, and measures and
summary management materialized views, view logs, and refresh
groups), schema administration (tables, indexes, views, synonyms,
sequences, database links, source types, and user types), and
workload administration (workload repository and SQL Tuning Sets).

Maintenance Page

The Maintenance Page has links to utilities
(export to files, import from files, load data from files, SQL Access
Advisor (described later), gather statistics, reorganize objects, and
make tablespace locally managed), recovery (backup, recovery, backup
settings, recovery settings, backup management, and recovery
catalog), and software management (patching).

Performance Page

The Performance Page graphically shows
parameters such as host run queue length, paging rate, instance
service time (CPU used, concurrency, scheduler, administrative,
configuration, system I/O, application, network, user I/O, commit,
and other workload), and instance throughput (logins and
transactions, physical reads and redo size). The page also has
additional monitoring links to Top Sessions, Top SQL, Advisor
Central, blocking sessions, database locks, instance activity, and
top consumers.

Advisor Central provides links to many
of the new tuning tools in Oracle Database 10g, including ADDM, SQL
Tuning, SQL Access, the Memory Advisor, Mean Time to Recovery (MTTR)
management, the Segment Advisor, and undo management
tools.

Figure 5-2. HTML console

Oracle Database 10g also includes a more sophisticated scheduler that
enables control of when and where jobs take place. The scheduler
programs describe the names of programs to be run, the types of
programs, and the program arguments. Jobs are created through the
link in the Administrator Page to specify what is to be executed
(e.g., a specific PL/SQL program you name for execution) and an
execution schedule. Job parameters specified include description, log
level, job class, whether a job can be restarted, and the PL/SQL
statement to be used. Jobs can be scheduled to run immediately or at
specific times. A schedule can be shared by multiple jobs.

5.1.4 EM2Go

EM2Go is a mobile
version of Enterprise Manager introduced with Oracle Database 10g. It
can be used for remote wireless management of database instances and
Oracle Application Server. Providing a subset of the functionality in
Enterprise Manager, EM2Go leverages the previously described Oracle
Management Service, associated Management Repository, and Oracle
Agents in the EM architecture. The Enterprise Manager Console is
accessed through a Pocket PC browser on a PDA device. Communication
between the Console and OMS and between OMS and the agents is via
HTTP. The administrator begins by logging into Oracle Enterprise
Manager from the EM2Go home page by entering the appropriate EM
username and password. Upon logging in, the administrator is
presented with a summary of alerts, database and Application Server
availability, and links to more detailed information describing the
alerts, availability, and performance of the targets being monitored.

Database administration capabilities in EM2Go include the ability to
perform basic administration tasks on control files, tablespaces,
datafiles, rollback segments, redo segments, redo log groups, and
archive logs. The performance management interface has links into the
current Top
Sessions, which identify the sessions consuming the most time and
resources, their associated SQL statements, and wait status, as well
as information on locks, and the Top SQL assessment.

Host monitoring provides a view of the health of the underlying
hardware and operating system. Application Server monitoring includes
performance statistics and enables setting of thresholds to more
easily determine the severity of reported statistics.