Thursday, February 28, 2008

java.lang.Exception: Exception in sending Request :: null

When accessing Enterprise Manager DB Control Console a couple of error messages display, right after providing the sys credentials, the console appears with a down arrow and at the header it says:

java.lang.Exception: Exception in sending Request :: null

If you try to move to another tab, such as the performance tab, it asks for credentials and responses:

Io exception: Unknown host specified

These are symptoms of a not properly configured Agent Time Zone.

Troubleshooting Agent Time Zone
This case happened to me on a Windows XP Professional in Mexican Spanish after a timezone change. I notice a similar error shows up on databases affected by the automatic time zone changes after synchronization with the, which recently has included two time zones for Mexico - one named old and the other named new-

0. Consider these files when performing the troubleshooting phase:

1. Stop the console
\bin\emctl stop dbconsole

2. Backup the file located at ORACLE_HOME/hostname_SID/sysman/config/

3. Edit the file and look for the agentTZRegion (generally appears at the end of the file)

At the file, located at the ORACLE_HOME/hostname_instanceName/sysman/config

change the value

agentTZRegion=GMT To agentTZRegion=America/Mexico_City

Evidently, this is for the particular case of Mexico City, but similar issues could apply to other time zones.
For other timezones affected, such as the one corresponding to Egypt, change the value of this parameter from GMT+2 to Egypt which is included in the supportedtzs.lst file.
So the parameter will be agentTZRegion=Egypt

4. When agent is unable to find a proper time zone it will adopt GMT, so it could be the value registered so far. Change this value by the value corresponding to the OS time zone, this time zone should be one listed at the ORACLE_HOME/sysman/admin/nsupportedtzs.lst file.

5. Execute this command
emctl resetTZ agent
emctl config agent getTZ

After issuing the resetTZ command a similar issue like this one may appear:
To complete this process, you must either:

connect to the database served by this DBConsole as user 'sysman', and execute:

SQL> exec mgmt_target.set_agent_tzrgn('','America/Mexico_City')

-- or --

connect to the database served by this DBConsole as user 'sys', and execute:

SQL> alter session set current_schema = SYSMAN;
SQL> exec mgmt_target.set_agent_tzrgn('','America/Mexico_City')

In order for these commands to be successful, you are required the agent to have registered some values at the EM repository. Check this query, there should be similar information displayed when connected as sysman:
SQL> select target_name, target_type from mgmt_targets;

------------------------------------ host oracle_database oracle_emd
Management Services and Repository oracle_emrep oracle_listener

6. The previous command will ask to perform some actions at the sysman repository level. Execute the reset at the repository level by:
SQL> alter session set current_schema = SYSMAN;

SQL> exec mgmt_target.set_agent_tzrgn('hostname:3938','TimeZone');

This command should be successful, otherwise it could be because the agent hasn't ever started and it has never registered, even with the wrong TZ at the repository.

In order for you to verify this has ever run and the agent is properly registered, issue this query as sysman:

SQL> select target_name, target_type from mgmt_targets;
The target with the default port 3938 is the target we are looking for.

The target related to the port 3938 should be listed. Otherwise try to start the agent so it can register this target. If agent is not starting, please veriy at the logs what could be a reason that prevents agent from starting. Most of the times it is because of a wrong specified

6. Try to login to the dbconsole and check if the error still exists.

7. Now start the EM Console, the problem should be fixed by now.

The value of the time zone is a valid value listed at ORACLE_HOME/sysman/admin/nsupportedtzs.lst Make sure the time zone matches that of the host computer.

if when executing the emdctl command an error related to java appears, it is because the right java version is not being invoked. Make sure the path environment variable properly includes the jdk environment provided at the same Oracle Home where the database is related to.



Problem: Startup Agent: ORA-20233: Invalid agent name when running mgmt_target.set_agent_tzrgn procedure in repository
Doc ID: Note:388280.1 --> This note has particularly helped me to solve my particular issue.

Problem: Startup Agent: EM Agent will not start due to Timezone mismatch (Daylight Savings changes for Australia)
Doc ID: Note:362888.1 --> some useful ideas were taken from this note

Problem: Startup Agent: Agent Fails to Start due to Incorrect Timezone File Used as Pointed by ORA_TZFILE
Doc ID: Note:409121.1

Problem: Startup Agent: ORA-20233: Invalid agent name when running mgmt_target.set_agent_tzrgn procedure in repository
Doc ID: Note:388280.1


Subhasis said...

The suggestions really helped me.

Nice said...

The suggestion is not usefull

Hector Rivera Madrid said...


This article refers to the TZ issues on an unpatched 10gR2 database on a windows platform. If your scenario doesn't have to do with this article, most probably this will be irrelevant to your specific case. If you would at least specified the platform you are working with as well as the scenario you are facing this could have made your comment useful.

Benjamin said...

Fought with this issue for three days before coming across this article, which solved the problem.
Thanks muchos.

Rumon said...

I don't have the property "agentTZRegion" in my file!

Can you tell me how to solve the problem now?

Hector R. Madrid said...


First of all it is very important to point out that whenever you post an issue on any blog or forum you must explicitly define the OS and DB versions you are referring. This issue is relatively old, this used to be shown on the unpatched 10g Rel 2 version. Assuming you refer to the DB version for Windows (a supported windows platform), I strongly suggest you to apply the latest patchset for this platform ( this is the first option to choose to solve this issue since this patchset already included the TZ fix.

pbsl said...
This comment has been removed by a blog administrator.
shah said...

My PC timezone is (UTC+5:30) and in my file I changed agentTZRegion = (UTC+5:30) and in supporttzs file I changed to (UTC+5:30)Chennai,Kolkata,Mumbai,New Delhi
I started using the cmd emctl config agent getTZ.I am getting GMT.can anyone help me out.Thanks in advance.

Hector R. Madrid said...

You must specify in detail what's your O.S. platform and the 5 digit DB Version, as well as the procedure you are following. Otherwise it is impossible to help you by guessing.

wet-Eyes said...

Thanks man, its really works and now there is no issue in EM,
Thanks a lot for your great research.