Hello, I'm going to show you how to monitor a database in an Oracle Cloud
Database as a Service instance
using the Database as a Service Monitor. When a database is created,
network access to the virtual machine hosting the database
is limited to Secure Shell SSH connections on port 22.
This access restrition ensures that the instance is secured by default.
To access the Database as a Service Monitor,
you can either ask your cloud service administrator to open port 443
or you can use SSH client software such as PuTTY
to create an SSH tunnel to port 443 to connect securely to the database.
Here is a putty connection defined with an SSH tunnel
using port forwarding from local port 443
to port 443 on the destination VM
that hosts a cloud database. The destination is specified using the IP
address of the VM
concatenated with :443. Once you've opened port 443 or created an SSH tunnel
to port 443,
navigate to the Oracle Database Cloud Service Console.
Click the Menu icon on the right, beside the database instance you want to
monitor
and select
Open DBaaS Monitor Console. Notice the other consoles you can open for Oracle
Application Express,
GlassFish administration, and Enterprise Manager Express.
Another way to access
the DBaaS Monitor console is to click on the database name you want to monitor
and then click
the menu icon at the top right of the page.
A new page is open in the browser with the URL
HTTPS, your instance
IP address, dbaas_monitor.
You are prompted for a username and password.
Enter dbaas_monitor as the username
and whatever password was specified when your cloud database instance was created.
The database monitor console appears
and displays generic information about the status of your database.
This monitor home page allows you to monitor and configure the database as
well.
Here we see that the database is up and running,
it is using 2.02 gigabytes of storage,
there are 44 active and 3 inactive sessions
(the database allows a maximum of 472 open sessions)
and there are 19 errors in the alert log file.
To access the monitor page,
click the Monitor tab at the top of the page
and select RDBMS or select RDBMS
in the monitor section of the page. The database monitor page displays four
sections:
Storage, Alert Log, Sessions, and Wait Events.
Each section links to a more detailed view of the monitored area.
Click Storage. Wait a few seconds
for the result to appear. The Storage page displays a breakdown of the storage
currently allocated by the database.
The inner ring shows the distribution of the
allocated space among the different tablespaces, while the outer ring
represents the used space in each table space. The outer ring
also shows the free space in a tablespace. To get the details about the segments that
use space in one of the tablespaces
click the tablespace name on the right of the page.
The tablespace detail page provides an interactive report
on the segments that exist within the tablespace.
Most segments are User objects and they include tables,
large objects, and indexes. Returning to the database monitor page
click Alert Log. An interactive report displays the entries in the database's
alert log.
The alert log is a chronological log of messages and errors
commonly used to learn whether the background processes have
encountered errors. Among the entries you will find critical errors,
administrative operations, process errors, and other database events.
Returning to the database monitor page,
click Sessions to view open user sessions.
An interactive report displays information about all currently open
sessions in the database.
the topmost table shows summarized data about each open session.
Click on any row in this table
to see more detailed data about that session.
Returning to the database monitor page,
click Wait Events to view the wait events in real time.
In this example
the wait events are essentially those of CPU consumption,
plus a little bit of system i/o in various weights categorized as "Other".
Returning to the database monitor
page, click the Configure tab at the top of the page and select
RDBMS. The database configuration page displays two sections:
Configure Database and Features.
The Features section reports the enablement status of major Oracle
database features.
In this example, the Oracle Real Application Clusters option
is not enabled, while Application Express,
Multimedia, Spatial, OLAP, and
XDB are enabled.
In the Configure Database section, click parameter settings
to view or modify current parameter values.
The Database Parameters page appears.
To modify the value of a parameter, select the parameter,
change its value
and click the
Save Change button at the top. You have an opportunity to review your change
before applying it. Changes that are saved to memory will take effect
immediately across all sessions
but will be lost upon the next instance shutdown. Changes that are saved to the
SP file
will take effect upon the next instance startup and are persistent.
And that's it.
You now know how to use the database monitor. For more information about
Oracle Database as a Service,
see the documentation and the learning materials in the Oracle Learning Library.
Thank you for watching.