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EM Express 12c Database Administration Page FAQ

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EM Express is a database management tool that focuses primarily on performance management and monitoring.  However, it does include basic administration functions to assist the database administrator. When users first log into EM Express, they see the home page which displays information about the database, as well as performance data, such as resource usage, average active sessions, and monitored SQL statements.

The three main categories of administrative tasks are:

1- Configuration

The four main features available in the Configuration menu are Initialization Parameters, Memory Configuration, Database Feature Usage and Database Properties.

Database Administrators can view and set initialization parameters for one or more instances of the database.  They can also determine how memory has been configured, and in particular, the amount of memory allocated to the SGA and PGA, the top processes consuming memory, and whether or not any of the automatic memory management features are in use.  In addition, memory advisor data is also displayed on the page.  To see an example of the Memory page, click here.


2- Storage

As part of Storage administration, DBAs can manage redo logs, archive logs, and tablespaces (view space consumption, create and/or alter tablespaces).  In addition, DBAs are also given some visibility into the control file contents.  DBAs can also view the Undo Advisor, as well as undo statistics, such as the undo generation rate and undo space usage.  To see an example of the Undo Page, click here.

3- Security

DBAs can use the features available in the Security menu to manage users, roles and profiles by creating, altering or granting and revoking privileges from them.

 

Frequently Asked Questions

How can I see Advisor Data on the Memory Page?

The advisor data visible at the top right panel of the Memory page is dependent on the memory configuration settings that are in use. 
If Automatic Memory Management is used, then only the Memory Advisor is displayed on the page. 
If Automatic Shared Memory Management is used, then the SGA Advisor, along with the PGA Advisor is displayed.
If Manual Shared Memory Management is used, then the Buffer Cache Advisor, along with the PGA Advisor is displayed

I'm trying to perform a task that I used to do in DB Control.  Where is it in EM Express?

EM Express is not a direct replacement for DB Control.  EM Express is built inside the database server and there are limitations as to what it can do. EM Express is also focused on providing performance management and monitoring functionality, and is not meant to be an all around database administration tool.

Oracle Database 12c also introduces Oracle Enterprise Manager Cloud Control (Cloud Control). Cloud Control provides you with complete monitoring across the Oracle technology stack and non-Oracle components. You must install Cloud Control separately after installing Oracle Database 12c , No additional license required .

Enterprise Manager Cloud Control supports Oracle Database 12c targets, including multitenant container databases (CDBs), pluggable databases (PDBs), non-CDBs, Oracle Real Application Clusters (Oracle RAC) databases, and Oracle Automatic Storage Management (Oracle ASM) databases.

Note:
Enterprise Manager Database Control is no longer available in Oracle Database 12c. You can use Enterprise Manager Cloud Control 12c or Enterprise Manager Database Express 12c to manage your Oracle Database 12c databases.

Why do I see a "Warning" icon on the Memory Page?

The warning icon is displayed if the memory configuration is different across the instances in your RAC cluster.  For example, this may be displayed if one instance uses Automatic Memory Management, while the other instance uses Manual Shared Memory Management.

In the Memory Page, why are the sizes in the Configuration region different from the Allocation region?

The configuration section shows the parameters that have been specified by the user, while the allocation section shows the amount of memory that has been allocated.  For example, if the system is using sga_target, the user can still specify minimum sizes for the different pools, and these sizes will be displayed in the Configuration section.  However, the allocation section will show what the system has allocated for the pools.

For an example, click here.  shared_pool_size=512M in the Configuration section, yet the Allocation breakdown shows 1G has been allocated.

In the Memory Page, why does sga_target in the Configuration region show a different value from the Current Setting in the SGA Advisor region?

This can happen on RAC.  The Configuration region shows the aggregate across all instances in the RAC target.  However, when showing the SGA Advisor data, if the sga_target is the same on all instances, it shows the advisor data based on the sga_target setting of the instances, with the estimated percentage of time taking into account the time saved over all instances.

For an example of a 2-node RAC environment with sga_target=2000M on each node, click here.  The page shows sga_target=3.9G, but the Current Setting in SGA Advisor shows 2G.

I'm on a RAC system, and the Home Page shows "Host CPU".  Which host is it showing?

This shows cluster CPU utilization.  If you have a symmetric cluster, this is the average of CPU utilization across all the nodes.  If you have an asymmetric cluster, then this shows the utilization over the entire cluster, e.g. sum of CPU used / sum of available CPU.

Similarly, the other charts in the Resources region, such as Active Sessions and Memory, also show aggregated values over the entire cluster.  For an example, click here.

To see the details per instance, click on the RAC link in the Status region, from the live UI.

Why is the Storage menu missing the Tablespaces entry in a CDB?

Tablespaces are local to a PDB, so the Tablespaces entry is not available at the root container.  To view and manage tablespaces or datafiles on a PDB, go to the EM Express configured on that PDB.

Can I manage and create Common Users with EM Express?

Yes, Common Users can be created and managed from the root container.
At the PDB container, you can only create and manage local users.

Why is the whole Performance tab missing?

This Might Be Database Standard Edition which does not support Performance Feature/Option ,
You can double check by :
SQL> select * from v$version;

To interpret the output, please check: How To Find Which Oracle Database Edition Is Currently Running? (Doc ID 417573.1)
Please check  Feature Availability for Oracle Database Editions Documentation Link for

Why are tabs missing from the Performance Hub?

At the PDB container, only the Activity and Monitored SQL tabs are visible because these are the only tabs that display PDB-specific data.
At the root container, all tabs are available in the Performance Hub.

Can I see the activity breakdown by PDB?

Yes, at the root container, you can see the Average Active Sessions breakdown by container using the Home Page and the Performance Hub (Summary tab or Activity tab).
This data is taken from ASH, not metrics, so you might see a discrepancy when comparing average active sessions per container against a different breakdown.

Why do I see PDB$SEED when viewing Activity breakdown by PDB?

Although PDB$SEED is just a seed database, when queries are issued against CDB_* views, the server internally switches to all containers, including PDB$SEED, to retrieve data.  If there are frequent queries against CDB_* views, this could result in activity captured against PDB$SEED.

Can I plug and unplug PDBs with EM Express?

No, EM Express does not provide full CDB management capabilities in DB 12.1.0.1.0.

How can I tell if I'm connected to the root container or to a PDB?

You can get this information from the Status region in the home page.  If you are at the root container, the type will show "CDB (# of PDBs)", and if you are at the PDB, the region will include the Container Name to which you're connected. In addition, the blue panel at the top of the page will have an icon on the top left that indicates if the database is a CDB.  The database name will be displayed after the icon:

CDB


PDB



How do I log into EM Express?

EM Express can be accessed thorugh the URL to https://<hostname>:<port>/em
A login page will be displayed, and the user can log in with any valid DB credential or use the following query while connected to CDB or PDB to generate the URL :
For HTTPS :
SQL> SELECT 'https://'||SYS_CONTEXT('USERENV','SERVER_HOST')||'.'||SYS_CONTEXT('USERENV','DB_DOMAIN')||':'||dbms_xdb_config.gethttpsport()||'/em/' from dual;
SQL> SELECT 'https://'||SYS_CONTEXT('USERENV','SERVER_HOST')||':'||dbms_xdb_config.gethttpsport()||'/em/' from dual;

For HTTP :
SQL> SELECT 'http://'||SYS_CONTEXT('USERENV','SERVER_HOST')||'.'||SYS_CONTEXT('USERENV','DB_DOMAIN')||':'||dbms_xdb_config.gethttpport()||'/em/' from dual;
SQL> SELECT 'http://'||SYS_CONTEXT('USERENV','SERVER_HOST')||':'||dbms_xdb_config.gethttpport()||'/em/' from dual;

How can I find the port on which EM Express is configured?

There are two ways to find the HTTP/HTTPS port for EM Express:

lsnrctl status | grep HTTP


(DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=xxx.us.oracle.com)(PORT=5500))(Security=(my_wallet_directory=/u01/oracle/app/oracle/admin/orcl/xdb_wallet))(Presentation=HTTP)(Session=RAW)) --> this is For HTTPS

(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=xxx.us.oracle.com)(PORT=8080))(Presentation=HTTP)(Session=RAW)) --> this is For HTTP


or from SQL*Plus:

SQL> select dbms_xdb_config.gethttpsport() from dual;
SQL> select dbms_xdb_config.gethttpport() from dual;

How can I give users read-only access to EM Express?

To grant users read-only access so that they can view the UI but not make any changes, grant them the EM_EXPRESS_BASIC role as follows: SQL> grant EM_EXPRESS_BASIC to <user>;  

Does EM Express have support for RAC?

Yes.  EM Express is a database management tool that is automatically RAC-aware.  When connected to a RAC system, the information displayed is for the entire database, i.e. for all instances.  For example, the average active session values is aggregated across all instances.  In addition, an extra Instances tab is displayed in the Performance Region on the DB Home Page to show the distribution of average active sessions across instances.

When using EM Express on RAC, how can I see instance-specific information?

Although EM Express is RAC-aware in general, some pages will allow you to view instance-specific information as well.  There are two ways to get to this instance-specific information.

The first way is using the Status Region in the Home Page.  You can click the "RAC - <n> instance(s) up" link and it will take you to a page with the instance details.  You can now select an instance and navigate to the Performance Hub, the Instance Home Page, or the Memory Page for the selected instance.

The second way is through the Performance Hub.  If you click the RAC tab, you will see a list of instances.  From this list, you can now select an instance and navigate to the Performance Hub, the Instance Home Page, or the Memory Page for the selected instance.

For Undo Details, the information is always instance-specific.  When you navigate to the Undo Management page using the Storage menu, you are taken to a page that lists all the instances and the undo summary information for each instance.  You can now select an instance and navigate to the Undo Details Page for the selected instance.

EM Express seems slow when using HTTPS.  Why?

Some browsers disable caching if you are using SSL and have a self-signed certificate.  This is known to occur on Chrome and Safari.  To avoid this issue, use a CA certificate when using HTTPS or use a browser that supports caching when using self-signed certificates (Firefox or IE).

What is the recommended screen resolution for EM Express?

Although the EM Express UI dynamically resizes based on the screen real-estate available, it works best with resolutions of at least 1280x1024 or 1600x900.

Can I run EM Express in Safari?

Yes, you can run EM Express in Safari on MacOS.  You can also run EM Express in Safari 5.0.* on Windows, but Safari 5.1.* on Windows is known to have an issue with input text fields that prevents users from entering their username and password on the login page

How can I replace the default wallet/certificate?

The XDB wallet is stored in the $ORACLE_BASE/admin/<db_name>/xdb_wallet directory .  If ORACLE_BASE is not defined, the XDB wallet is stored in $ORACLE_HOME/admin/<db_name>/xdb_wallet, where <db_name> is the unique database name.

What should I do if the default XDB wallet expires?

If the wallet expires, you can create a new wallet with an existing SSL certificate and replace the existing wallet with the new one.  Alternatively, you can use dbms_xdb.installDefaultWallet() to replace the existing wallet with a new Oracle wallet that has a self-signed certificate.

Why am I getting a "This Connection is untrusted" message when I try to log into EM Express?  Is this a security concern?

The browser displays this message if you are using a self-signed certificate.  You can either create an exception for it, or you can replace the default wallet/certificate with a trusted certificate.  See the documentation for more information.  

Is EM Express secure?

Yes, EM Express uses SSL (HTTPS) out of the box.

Do I need any database privileges to use EM Express?

In order to use EM Express, a database user needs to have been granted the EM_EXPRESS_BASIC or EM_EXPRESS_ALL role.  The DBA role includes both the EM_EXPRESS_BASIC and the EM_EXPRESS_ALL roles.

EM_EXPRESS_BASIC grants a user read-only privileges, so that the user can view pages but not perform any actions.  EM_EXPRESS_ALL grants a user all privileges required to perform any action in EM Express.

Do I need licenses or packs to use EM Express?

You can use the basic administration features offered by EM Express with no additional licenses.  However, to use the performance features, you will need the Oracle Diagnostics Pack.  For the Performance Hub, you will need the Diagnostics Pack and for the SQL Monitor and SQL Tuning Advisor features, you will need the Tuning Pack.

Depending on what packs you own, you should set the control_management_pack_access init.ora parameter on your system.  For example, if you have the Diagnostics Pack, but not the Tuning Pack, you should set the control_management_pack_access parameter=DIAGNOSTIC.

Is EM Express supported on Oracle Database Standard Edition?  What about Database XE?

Yes, EM Express is supported on both Standard Edition (SE) and Express Edition (XE).  However, features that require the Diagnostics and Tuning Packs will not be available on SE and XE.  For example, the Performance Menu won't be available on SE and XE because the features require the Diagnostics or Tuning Packs.  Similarly, certain regions of the Home Page, such as the SQL Monitor List, will not be shown on SE and XE because they require the Tuning Pack.

How to configure EM Express on a CDB/PDB?

Users can configure EM Express both at the root and the PDB containers, with each container using a different HTTP/HTTPS port.  When connected to the root container, the information displayed is for the entire database including all PDBs.  When connected to a PDB, the information displayed is restricted to data for the PDB  Simply login to the container and set the HTTPS/HTTP port. 

By default, DBCA picks a free port from the 5500 to 5599 range to use as the EM Express port.

If you want a particular port to be used as the EM Express port, specify that port using the DBEXPRESS_HTTPS_PORT operating system environment variable prior to starting OUI or DBCA.

To start EM Express, use the EM Express URL provided by DBCA when DBCA configured your database, there are two ways to find the HTTP/HTTPS port for EM Express:  

lsnrctl status | grep HTTP

(DESCRIPTION=(ADDRESS=(PROTOCOL=tcps)(HOST=xxx.us.oracle.com)(PORT=5500))(Security=(my_wallet_directory=/u01/oracle/app/oracle/admin/orcl/xdb_wallet))(Presentation=HTTP)(Session=RAW)) --> this is For HTTPS

(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=xxx.us.oracle.com)(PORT=8080))(Presentation=HTTP)(Session=RAW)) --> this is For HTTP

or from SQL*Plus:
SQL> select dbms_xdb_config.gethttpsport() from dual;
SQL> select dbms_xdb_config.gethttpport() from dual;


or use the following query while connected to CDB or PDB to generate the URL :
For HTTPS:
SQL> SELECT 'https://'||SYS_CONTEXT('USERENV','SERVER_HOST')||'.'||SYS_CONTEXT('USERENV','DB_DOMAIN')||':'||dbms_xdb_config.gethttpsport()||'/em/' from dual;
SQL> SELECT 'https://'||SYS_CONTEXT('USERENV','SERVER_HOST')||':'||dbms_xdb_config.gethttpsport()||'/em/' from dual;

For HTTP :
SQL> SELECT 'http://'||SYS_CONTEXT('USERENV','SERVER_HOST')||'.'||SYS_CONTEXT('USERENV','DB_DOMAIN')||':'||dbms_xdb_config.gethttpport()||'/em/' from dual;
SQL> SELECT 'http://'||SYS_CONTEXT('USERENV','SERVER_HOST')||':'||dbms_xdb_config.gethttpport()||'/em/' from dual;


When EM Express prompts you for your username and password, log in as a user with DBA privilege (such as SYS).
Note: The first time you enter the URL for EM Express in your web browser, your browser may display warning messages.

EM Express is a servlet built on top of Oracle XML DB. The Oracle XML DB default wallet has a self-signed certificate, and some existing browsers consider self-signed certificates as untrusted because they are not signed by a trusted CA (certificate authority). However, the self-signed certificate is still secure, as it ensures that the traffic is encrypted between the Oracle XML DB server and the client (browser).

Therefore, enter a security exception for the EM Express URL in your web browser.

To manually configure the HTTP/HTTPS port for EM Express:
1- If the listener is running on a nonstandard port (for example, not 1521), then the init.ora file for the database you want to manage using EM Express must contain a local_listener entry so that the HTTP/HTTPS port can register with the correct listener. The local_listener entry references a TNSNAMES entry that points to the correct listener. For example:
    local_listener=inst1

where inst1 is a TNSNAMES entry defined in tnsnames.ora that points to the listener. For example:
    inst1= (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=host_name)(PORT=1234))
    (CONNECT_DATA=(SERVICE_NAME=service_name)(SERVER=DEDICATED)))

2- Enable the TCP dispatcher by adding the following entry to the init.ora file for the database you want to manage using EM Express:
    dispatchers="(PROTOCOL=TCP)(SERVICE=<sid>XDB)"

    For example, if the database SID is ORCL, then the entry would be:
    dispatchers="(PROTOCOL=TCP)(SERVICE=ORCLXDB)"

3- Use the PL/SQL procedure DBMS_XDB_CONFIG.SETHTTPSPORT to set the HTTPS port for EM Express. This will update the HTTPS port in the xdbconfig.xml file in the Oracle XML DB Repository. You must connect as SYS / AS SYSDBA to run the procedure. For example:

SQL> connect sys/<password>@<container> as sysdba
SQL> exec DBMS_XDB_CONFIG.SETHTTPSPORT(5500);
or use the PL/SQL procedure DBMS_XDB_CONFIG.SETHTTPPORT to set the HTTP port for EM Express. This will update the HTTPS port in the xdbconfig.xml file in the Oracle XML DB Repository. You must connect as SYS / AS SYSDBA to run the procedure. For example:

SQL> connect sys/<password>@<container> as sysdba
SQL> exec DBMS_XDB_CONFIG.SETHTTPPORT(2200);

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Comments ( 1 )
  • guest Friday, November 21, 2014

    Hi ,

    How do I see scheduler jobs in EM Express ? Pre-12c, we used to get the information from "Server -> Jobs" . I am not seeing that option in EM Express ?

    Is there any document that provides the difference between 11g and 12c ?

    Thanks

    Zahir M


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