Monthly Archives: February 2016

WORKAROUND: Unable to monitor Oracle XE 11gR2 with Oracle Enterprise Manager 13c

I have recently switched to using Oracle Enterprise Manager 13c (EM13c – 13.1), replacing my previous EM12c installation.  I elected to install a clean new environment instead of an upgrade, because my old install had been upgraded repeatedly going back to the initial release of EM12c and I wanted a fresh start.

I encountered only one difficult issue during the process. When I attempted to add one production Oracle XE 11gR2 database target, EM13c could not compute the target’s dynamic properties, leaving the target broken. Since you cannot submit jobs against a broken target, this prevented me from using EM13c to back up this database.  I had no comparable issues with XE as a target under EM12c.

The key metric errors that showed during this process included:
“Metric evaluation error start – Target {oracle_database.SID.domain.com} is broken: Dynamic Category property error,Get dynamic property error,No such metadata – No valid queryDescriptor or executionDescriptor found for target [oracle_database.SID.domain.com$30]”

and for the database system target:

“Metric evaluation error start – Received an exception when evaluating sev_eval_proc for:Target name = SID.domain.com_sys, metric_name = Response, metric_column = Status; Error msg = Target encountered metric erros; at least one member in in metric error”

I enabled debugging for the agent logs and attempted again to add the XE target.  Errors showing up in the logs included:

2016-01-15 12:10:05,905 [1806:4CE3192] DEBUG – Computing of dynamic property: [ComputeVC] is done (1 msec, error=true)

2016-01-15 12:10:06,452 [1806:F917F5F8] DEBUG – Computing of dynamic property: [GetDumpDestination] is done (0 msec, error=true)

2016-01-15 12:10:06,508 [1813:6EEEAC87] DEBUG – Computing of dynamic property: [DeduceAlertLogFile] is done (1 msec, error=true)

2016-01-15 12:11:18,779 [1830:CD3A325D] DEBUG – Error was added to oracle_database.SID.domain.com$23(0|MONITORED|false|true|<UF>): Invalid Input

2016-01-15 12:11:18,779 [1831:3657AE55] DEBUG – abandoning long op “CDProps:oracle_database.SID.domain.com:ComputeVC:GENERIC_TASK:Fri Jan 15 12:11:18 EST 2016”

2016-01-15 12:11:18,780 [1830:CD3A325D] DEBUG – Error during dynamic property ComputeVC calculation: critical=true, missingCatProps=[VersionCategory], missingProps=[VersionCategory] oracle.sysman.emSDK.agent.fetchlet.exception.FetchletException: Invalid Input

2016-01-15 12:35:38,038 INFO – Finished dynamic properties computation (total time 817 ms). Number of DP computed: 19. Number of DP with error: 3. Number of dynamic properties that were added: 132.

After reviewing the logs carefully (and posting this as a question in the MOS Oracle XE forum – https://community.oracle.com/thread/3892946) I eventually narrowed the issue down to a query that EM13c runs against DBA_REGISTRY_HISTORY in a target database when added. For database versions greater than 11.2 but less than 12.1.0.2, EM13c assumes that DBA_REGISTRY_HISTORY contains a BUNDLE_SERIES column.  This column does not exist in Oracle XE 11gR2, which reports a version string of 11.2.0.2.

This bug should eventually get a fix as EM13c gets patched, but in the meantime if you need to monitor an Oracle XE target with EM13c, the following workaround took care of the problem for me: create a new DBA_REGISTRY_HISTORY table containing a BUNDLE_SERIES column in your monitoring user’s schema in XE.  So, as user DBSNMP on XE, I ran:

SQL> create table dba_registry_history (ACTION_TIME TIMESTAMP(6), ACTION VARCHAR2(30), NAMESPACE VARCHAR2(30), VERSION VARCHAR2(30), ID NUMBER, BUNDLE_SERIES VARCHAR2(30), COMMENTS VARCHAR2(255));

Since one cannot patch XE, the real DBA_REGISTRY_HISTORY view has no rows and so you do not need to populate any data into this new table.

After adding the table, force a recalculation of dynamic properties by running the following against the EM13c management agent on the XE server:

$ emctl reload agent dynamicproperties SID.domain.com:oracle_database
Oracle Enterprise Manager Cloud Control 13c Release 1
Copyright (c) 1996, 2015 Oracle Corporation.  All rights reserved.
---------------------------------------------------------------
EMD recompute dynprops completed successfully

Once that completed successfully my XE target started to show the correct status in EM13c and I can submit jobs against the target.  All fixed.  I recommend deleting the DBSNMP.DBA_REGISTRY_HISTORY table once the bug gets fixed in OEM.

[EDIT 20160216: Oracle has documented this issue in MOS note EM13c: Database Target Status Shows “Dynamic Category property error” In 13c Cloud Control (Doc ID 2105001.1) and in bug 22592461 DATABASE TARGET STATUS SHOWS “DYNAMIC CATEGORY PROPERTY ERROR” IN 13C CONSOLE. Users on supported databases (e.g., not Oracle XE) should follow the resolution steps in that document instead to correct the real error.]