快餐文化笼罩着整个世界。

解决完问题后，莫名其妙地不让问题再出现之后，就接手第二件事情，基本的技能却没有掌握。

居其位，谋其职，不同层次的人会从事不同层次的工作。

从低到高，应该是一个积累的过程。要不就不会出现眼高手低的案例了。

或者说，快餐带给人们的只是暂时的满足，一般的温饱问题。而酒楼，咖啡厅....带给人们的才是更高的享受。

 

So hard a topic, because now I am just familiar with TopLink.

 

First expression, Hibernate is simple, easy to start, but TopLink seems so sophisticated when trying to get started.

 

Configuration file:

Hibernate use a .hbm xml file to describe a corresponding POJO.

TopLink use project.xml, it contains the descriptors and mappings you define and also includes any named queries or finders associated with your project. Each TopLink project belongs to a TopLink session. sessions.xml is mainly used to specify the login info for projects.

But TopLink's project.xml is so complicated that ususally be generated by JDeveloper or WorkBench, for example, when run deploy command in JD,  the project.xml is generated automately. and JDeveloper use a lot of other intemedial xml file to hold the configuration, just in development time, which located in toplink sub-folder, such as HRMap.mwp,oracle.datamodel.Departments.ClassDescriptor.xml, etc.

 

Above TopLink, some higher level technologies used, such as EJB, ADF data control. so the data model layer, *only this layer*, become more complicated and more complicated.....

 

More discussion about the differences between Hibernate and TopLink maybe be delayed....until necessary.

 

 

健康是1,其它都是0，这个1呢，在最左边，于是，没有了这个1，即便亿万身价，倏忽间就成了零。

 

重要的事情是1,紧急的事情是0。

 

善待自己，才能善待别人。

 

对自己负责，才能对别人负责。

 

So, self service and self discipline.

I have found out that for my single instance configuration (no grid agents), the common cause of
"Agent process exited abnormally during initialization" in system event log,
"java.lang.Exception: Exception in sending Request :: null" in OEM Database Control Database Instance home page
"status pending" in OEM Database Control Database Instance home page
"Io exception: Unknown host specified" in OEM Database Control Database Login
was an incorrect time zone autoconfigured by the Database Control service.

On Windows 2000 / XP, for the OEM single instance control, (with no grid agent) the service OracleDBConsole<SID> runs both a control service and an agent. After creation of the database using the Database Configuration Assistant 10.2.0.2, the <ORACLE_HOME/><host name _SID>/config/emd.properties file was created with no agentTZRegion parameter.
At the first startup of the agent, it recognised this and added a line "agentTZRegion=GMT" (the correct time zone would have been Australia/Melbourne). This action is reported in <ORACLE_HOME>/<host name _SID>/emdb.nohup:

----- Fri Apr 28 17:57:51 2006::Console Launched with PID 3348 at time Fri Apr 28 17:57:51 2006 -----
----- Fri Apr 28 17:59:26 2006::Property 'agentTZRegion' is missing from C:\oracle\product\10.2.0\db_1\AMAZON.RUBICON.COM.AU_DAP1/sysman/config/emd.properties. This is normal when the agent is started for the very first time.Updating it... -----
----- Fri Apr 28 17:59:26 2006::C:\oracle\product\10.2.0\db_1\AMAZON.RUBICON.COM.AU_DAP1/sysman/config/emd.properties copied to C:\oracle\product\10.2.0\db_1\AMAZON.RUBICON.COM.AU_DAP1/sysman/config/emd.properties.2006-04-28-17-59-26 while updating the property 'agentTZRegion' -----
----- Fri Apr 28 17:59:35 2006::An agentTZregion of 'GMT' is installed in C:\oracle\product\10.2.0\db_1\AMAZON.RUBICON.COM.AU_DAP1/sysman/config/emd.properties. -----
----- Fri Apr 28 17:59:36 2006::The agentTZRegion value in C:\oracle\product\10.2.0\db_1\AMAZON.RUBICON.COM.AU_DAP1/sysman/config/emd.properties is not in agreement with what agent thinks it should be.Please verify your environment to make sure that TZ setting has not changed since the last start of the agent.
If you modified the timezone setting in the environment, please stop the agent and exectute 'emctl resetTZ agent' and also execute the script 'mgmt_target.set_agent_tzrgn' to get the value propagated to repository -----

As you can see, the agent adds the agentTZRegion parameter and immediately recognises that it has set the wrong value. (Possibly this could be avoided by setting a system TZ environment variable before creating the database.) The agent fails, and the service ends up with a java process running, but the service not properly started, so you can't restart it via the services console.
"emctl status dbconsole" says it is not running.

Once this has happened,future startups of the OracleDBConsole<SID> report the last of the errors (the one starting "::The agentTZRegion value in") and again the agent fails.

The solution is
1. Kill the java process which is the console portion of OracleDBConsole<SID>
2. Edit the emd.properties file to have the correct timezone
3. Reboot or restart the OracleDBConsole<SID>

Note that deleting and recreating the service via "emca -deconfig dbcontrol db -repos drop" and "emca -config dbcontrol db -repos create" does not cure the problem - it again creates an emd.properties file with no agentTZRegion value.

I already had installed the Microsoft Loopback Adapter, and added its IP address to drivers/etc/hosts as per the Oracle Windows installation guide for DHCP computers.

 

from http://forums.oracle.com/forums/thread.jspa?messageID=1374397

referred by

https://metalink.oracle.com/metalink/plsql/ml2_documents.showDocument?p_database_id=FOR&p_id=656162.992
also Doc 351322.1 in metalink discuess the same problem.

 

The Loopback Adapter seems not the focus point of this problem, since in my machine I haven't configure this, and everything goes OK.

And the timezone supported can be found at: %ORACLE_HOME%\sysman\admin\supportedtmz.lst

Another note when installing Oracle in Linux is that /etc/hosts must be checked carefully, or else the emca will be failed, left the problem confused. It should be like below.

127.0.0.1 localhost.localdomain localhost

<IP> <hostname>

 

and then the emca will recognize the hostname as <hostname>, not localhost.localdomain etc, which cause the OEM can't display correctly.

Effectively and quickly

anybody tell me?