Target Re-Configuration in OEM gives ==> Connection Failure May Be Due To A Slow Network, or to the presence of intervening firewall

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## Error
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Connection Failure May Be Due To A Slow Network, or to the presence of intervening firewall

### Full Error

Connection Failure May Be Due To A Slow Network, or to the presence of intervening firewall

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#  Error Occurred
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Error occured while trying to resolve metric collection error for a cluster database in 11.2.0.2.0 GI version

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## Command Executed
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Reconfiguration of Target in OEM

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## Issue Description.
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### 11.2.0.2.0

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# Metric Collection Errors
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One of our database is in metric collection Error, So when trying to re-configure the database in OEM got the connection failure error.

This may be because of the network issue between Agent and OMS server. In our case all the targets in this server are working fine. So this is not the issue

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## Solution
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Database has archive issues, FRA has become 100% full. Due to which agent cant communicate with the database.



set lines 200
select * from v$flash_recovery_Area_usage;

FILE_TYPE            PERCENT_SPACE_USED PERCENT_SPACE_RECLAIMABLE NUMBER_OF_FILES
-------------------- ------------------ ------------------------- ---------------
CONTROL FILE                        .05                         0               1
REDO LOG                              0                         0               0
ARCHIVED LOG                      99.76                         0             136
BACKUP PIECE                          0                         0               0
IMAGE COPY                            0                         0               0
FLASHBACK LOG                         0                         0               0
FOREIGN ARCHIVED LOG                  0                         0               0

7 rows selected.

After running an archivelog backup issue got resolved.

So next time when a database has metric collection errors, dont forget to check the archive usage too.