This is the recorded presentation of the Oracle Enterprise Manager 12c @JoinSQL seminar held in Romania last month. Hope you find it interesting.
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Where did my day go?: Oracle Enterprise Manager 12c Administration. IOUG Collaborate 2015 slides
I uploaded the slides of my IOUG’s Collaborate presentation about OEM 12c.
Thanks,
Alfredo
Stabilize Your Plans with SQL Plan Management Including 12c. IOUG Collaborate 2015 slides
Free Database Seminar in Timisoara, Romania
Today I want to talk about a free Database Seminar that ACI is sponsoring in Timisoara, Romania. A friend of mine and former co-worker asked me to speak in the seminar about Oracle Enterprise Manager Administration.
Because of the Time zone’s differences, I’m going to make a recording of the presentation and upload it to the blog, so he can show it there.
If you are nearby Timisoara, don’t loose the opportunity to assist and learn little bit more about databases.
The event is going to take place April, 8th at 5 pm @ City Business Centre, building D, Timisoara, RO.
Did I forget to mention that the event is for free?
For more information go to:
Thanks,
Alfredo
RMAN jobs not working after OEM upgrade to 12.1.0.4
If you are planning to upgrade your OEM to 12.1.0.4 and you have RMAN jobs scheduled in Cloud Control, you should consider applying patch 19519190 to the OMS. I noticed that most of the RMAN jobs were having issues and even worst, some steps were empty!!!
Obviously, the jobs were succeeding as the step is empty. In other words, the jobs were doing nothing.
Looks like this patch is not part of any PSU, yet! But having a problem with hundreds of jobs and especially with RMAN jobs is very risky.
Take a look at EM 12c: RMAN Step Commands are Being Removed from Multi-step RMAN Script Jobs in Enterprise Manager 12.1.0.4 Cloud Control (Doc ID 1914916.1).
Thanks,
Alfredo
Using OMS DEBUG mode to troubleshoot OEM 12c problems
This time, I want to show you how to troubleshoot OEM problems by enabling DEBUG mode in the OMS. The virtual machine (VM) running my sandbox installation of OEM 12c 12.1.0.4 crashed during the night. After restarting the VM and all the OEM components, I wasn’t able to login using the SYSMAN account. The error from the console was not very explicit, just, “Authentication failed. If problem persists, contact your system administrator.”
In order to get more details about the error, I decided to enable DEBUG mode for the OMS and reproduce the error. This is what I did to enable DEBUG mode.
$ cd /u01/app/oracle/oms/oms/bin
$ ./emctl set property -name log4j.rootCategory -value “DEBUG, emlogAppender, emtrcAppender” -module logging
Oracle Enterprise Manager Cloud Control 12c Release 4
Copyright (c) 1996, 2014 Oracle Corporation. All rights reserved.
SYSMAN password:
Property log4j.rootCategory has been set to value DEBUG, emlogAppender, emtrcAppender for all Management Servers
OMS restart is not required to reflect the new property value
After enabling DEBUG mode, I reproduced the error several times using the console. I also wrote down the approximate time of the error, just to easy the search in the log file. Searching in the emoms.trc file located under /em/EMGC_OMS1/sysman/log/, found an ORA-14400 error. The MOS note 1493151.1, explains how to fix the issue by adding a new audit partition.
$ cd /u01/app/oracle/gc_inst/em/EMGC_OMS1/sysman/log/
$ view emoms.trc
java.sql.SQLException: ORA-14400: inserted partition key does not map to any partition
The final step is to disable the DEBUG mode for your OMS, otherwise the log files can grow real big and the performance could be affected.
$ ./emctl set property -name log4j.rootCategory -module LOGGING -value “WARN, emlogAppender, emtrcAppender”
Oracle Enterprise Manager Cloud Control 12c Release 4
Copyright (c) 1996, 2014 Oracle Corporation. All rights reserved.
SYSMAN password:
Property log4j.rootCategory has been set to value WARN, emlogAppender, emtrcAppender for all Management Servers
OMS restart is not required to reflect the new property value
I hope this information is useful to you next time you are troubleshooting an OEM 12c issue.
Thanks,
Alfredo
OEM 12c very slow after upgrade to 12.1.0.4
I noticed that OEM 12c console was very slow a few hours after the upgrade to 12.1.0.4 version.
Looking at the repository DB, found several OMS sessions consuming significant CPU resources.
Bug 19199023 explains that some SQL queries executed against the repository consume high CPU on the servers. This bug affects the DB plug-in 12.1.0.6 and the patch 19176910 should be applied to the plug-ins.
More information available on MOS note, 12.1.0.4 OEM: High CPU utilization on Repository Database due to SYSMAN query WITH TARGETGUID AS (SELECT target_guid, host_name FROM mgmt_targets (Doc ID 1912172.1)
Thanks,
Alfredo
Cannot start ASM – ORA-15063: ASM discovered an insufficient number of disks for diskgroup “DATA”
Today, I faced and issue with an ASM instance. After bouncing the server, CRS went up along with the ASM instance, but the diskgroups were offline.
$ crsctl status resource -t
——————————————————————————–
NAME TARGET STATE SERVER STATE_DETAILS
——————————————————————————–
Local Resources
——————————————————————————–
ora.DATA.dg
ONLINE OFFLINE hosta
ora.FRA.dg
ONLINE OFFLINE hosta
ora.LISTENER.lsnr
ONLINE ONLINE hosta
ora.LISTENER_1.lsnr
ONLINE ONLINE hosta
ora.asm
ONLINE ONLINE hosta Started
ora.ons
OFFLINE OFFLINE hosta
——————————————————————————–
Cluster Resources
——————————————————————————–
ora.cssd
1 ONLINE ONLINE hosta
ora.diskmon
1 OFFLINE OFFLINE
ora.evmd
1 ONLINE ONLINE hosta
ora.database.db
1 ONLINE OFFLINE Instance Shutdown
ora.database1.db
1 OFFLINE OFFLINE Instance Shutdown
I tried to start ora.DATA.dg resource, but it failed.
$ crsctl start resource ora.DATA.dg
CRS-2672: Attempting to start ‘ora.DATA.dg’ on ‘hosta’
CRS-5017: The resource action “ora.DATA.dg start” encountered the following error:
ORA-15032: not all alterations performed
ORA-15017: diskgroup “DATA” cannot be mounted
ORA-15063: ASM discovered an insufficient number of disks for diskgroup “DATA”
. For details refer to “(:CLSN00107:)” in “/u01/oracle/grid/log/hosta/agent/ohasd/oraagent_oracle/oraagent_oracle.log”.
CRS-2674: Start of ‘ora.DATA.dg’ on ‘hosta’ failed
CRS-2679: Attempting to clean ‘ora.DATA.dg’ on ‘hosta’
CRS-2681: Clean of ‘ora.DATA.dg’ on ‘hosta’ succeeded
CRS-4000: Command Start failed, or completed with errors.
After checking the RAW devices on the host, everything appeared to be properly configured. Then I checked the configuration of the ASM instance, finding the ASM_DISKSTRING empty.
$ crsctl stat resource ora.asm -f
NAME=ora.asm
TYPE=ora.asm.type
STATE=OFFLINE
TARGET=OFFLINE
ACL=owner:oracle:rwx,pgrp:oinstall:rwx,other::r–
ACTION_FAILURE_TEMPLATE=
ACTION_SCRIPT=
AGENT_FILENAME=%CRS_HOME%/bin/oraagent%CRS_EXE_SUFFIX%
ALIAS_NAME=
ASM_DISKSTRING=
AUTO_START=restore
CHECK_INTERVAL=1
CHECK_TIMEOUT=30
CREATION_SEED=11
DEFAULT_TEMPLATE=PROPERTY(RESOURCE_CLASS=asm) ELEMENT(INSTANCE_NAME= %GEN_USR_ORA_INST_NAME%)
DEGREE=1
DESCRIPTION=Oracle ASM resource
ENABLED=1
GEN_USR_ORA_INST_NAME=+ASM
ID=ora.asm
LOAD=1
LOGGING_LEVEL=1
NLS_LANG=
NOT_RESTARTING_TEMPLATE=
OFFLINE_CHECK_INTERVAL=0
PROFILE_CHANGE_TEMPLATE=
RESTART_ATTEMPTS=5
SCRIPT_TIMEOUT=60
SPFILE=+DATA/asm/asmparameterfile/registry.123.785123625
START_DEPENDENCIES=hard(ora.cssd) weak(ora.LISTENER.lsnr)
START_TIMEOUT=900
STATE_CHANGE_TEMPLATE=
STOP_DEPENDENCIES=hard(ora.cssd)
STOP_TIMEOUT=600
TYPE_VERSION=1.2
UPTIME_THRESHOLD=1d
USR_ORA_ENV=
USR_ORA_INST_NAME=+ASM
USR_ORA_OPEN_MODE=mount
USR_ORA_OPI=false
USR_ORA_STOP_MODE=immediate
VERSION=11.2.0.3.0
I updated ASM_DISKSTRING with the discovery path of the disks and then bounced ASM instance.
$ srvctl modify asm -d ‘/dev/sd*’
$ srvctl stop asm
$ srvctl start asm
After this the ASM instance came up cleanly and the diskgroups were mounted.
$ crsctl status resource -t
——————————————————————————–
NAME TARGET STATE SERVER STATE_DETAILS
——————————————————————————–
Local Resources
——————————————————————————–
ora.DATA.dg
ONLINE ONLINE hosta
ora.FRA.dg
ONLINE ONLINE hosta
ora.LISTENER.lsnr
ONLINE ONLINE hosta
ora.LISTENER_1.lsnr
ONLINE ONLINE hosta
ora.asm
ONLINE ONLINE hosta Started
ora.ons
OFFLINE OFFLINE hosta
——————————————————————————–
Cluster Resources
——————————————————————————–
ora.cssd
1 ONLINE ONLINE hosta
ora.diskmon
1 OFFLINE OFFLINE
ora.evmd
1 ONLINE ONLINE hosta
ora.database.db
1 ONLINE ONLINE Open
ora.database1.db
1 OFFLINE ONLINE Open
Hope this help you to troubleshoot and fix the issue on your ASM, when is not able to find the disks.
Thanks,
Alfredo
Understanding Oracle SQL Plan Management SPM – Part 3
This is the third post of SQL Plan Management. In the previous post, Understanding SQL Plan Management– Part 2, I described the three main components of SPM, this time I want to show you how to manually capture plans from the cursor cache. In other words, manually capture plans that reside in memory.
In order to manually capture plans, I’m considering that automatic capture is disabled or OPTIMIZER_CAPTURE_SQL_PLAN_BASELINES is set to FALSE. Oracle provides a function named DBMS_SPM.load_plans_from_cursor_cache to manual capture plans from cursor cache.
DBMS_SPM.LOAD_PLANS_FROM_CURSOR_CACHE (
sql_id IN VARCHAR2,
plan_hash_value IN NUMBER := NULL,
sql_text IN CLOB,
fixed IN VARCHAR2 := ‘NO’,
enabled IN VARCHAR2 := ‘YES’)
RETURN PLS_INTEGER;
The common use for this function, is to specify the sql_id of the statement we want to capture. We also can specify the plan_hash_value or the sql_text. Two more attributes can be set within this function, fixed is ‘NO’ by default and enabledis ‘YES’ by default. If you want to load plans, but you don’t want the CBO to make use if them; set the attribute enabled to ‘NO’.
In the below example I’m capturing all the SQL plans for sql_id4c372tsuhtunm and printing the number of plans loaded:
SQL> SET SERVEROUTPUT ON
DECLARE
l_plans_loaded PLS_INTEGER;
BEGIN
l_plans_loaded := DBMS_SPM.load_plans_from_cursor_cache(
sql_id => ‘4c372tsuhtunm’);
DBMS_OUTPUT.put_line(‘Plans Loaded: ‘ || l_plans_loaded);
END;
/SQL> 2 3 4 5 6 7 8 9
Plans Loaded: 8
PL/SQL procedure successfully completed.
To verify the SQL baselines created for this sql_id, I just need to query DBA_SQL_PLAN_BASELINES view:
SQL> select SIGNATURE,SQL_HANDLE,PLAN_NAME,ORIGIN,ENABLED,ACCEPTED,FIXED,REPRODUCED from dba_sql_plan_baselines;
SIGNATURE SQL_HANDLE PLAN_NAME ORIGIN ENABLED ACCEPTED FIXED REPRODUCED
——————— ——————— —————————— ————– ——- ——– —– ———-
5535156277878016190 SQL_4cd0d34ee73148be SQL_PLAN_4tn6m9vmm2k5ye8c8b02d MANUAL-LOAD YES YES NO YES
5535156277878016190 SQL_4cd0d34ee73148be SQL_PLAN_4tn6m9vmm2k5yc568a49d MANUAL-LOAD YES YES NO YES
5535156277878016190 SQL_4cd0d34ee73148be SQL_PLAN_4tn6m9vmm2k5ybff74238 MANUAL-LOAD YES YES NO YES
5535156277878016190 SQL_4cd0d34ee73148be SQL_PLAN_4tn6m9vmm2k5y0310173f MANUAL-LOAD YES YES NO YES
5535156277878016190 SQL_4cd0d34ee73148be SQL_PLAN_4tn6m9vmm2k5y8e42f3cc MANUAL-LOAD YES YES NO YES
5535156277878016190 SQL_4cd0d34ee73148be SQL_PLAN_4tn6m9vmm2k5y25375ef9 MANUAL-LOAD YES YES NO YES
5535156277878016190 SQL_4cd0d34ee73148be SQL_PLAN_4tn6m9vmm2k5y9de69d5d MANUAL-LOAD YES YES NO YES
5535156277878016190 SQL_4cd0d34ee73148be SQL_PLAN_4tn6m9vmm2k5yb76f0084 MANUAL-LOAD YES YES NO YES
8 rows selected.
Look at the data for the ORIGIN column, it shows from where the plans were loaded, either from manual load or auto capture.
Another method is to manual load plans from SQL Tuning Sets (STS). The STS may contain plans that are not present in memory, like plans in the AWR repository. This method is very useful when you want to create baselines of plans that were created by the CBO few days ago and are not in the cursor cache at this time. Keep in mind that STS requires a special license in order to be used. Oracle provides the function DBMS_SPM.load_plans_from_sqlset to accomplish this task.
DBMS_SPM.LOAD_PLANS_FROM_SQLSET (
sqlset_name IN VARCHAR2,
sqlset_owner IN VARCHAR2 := NULL,
basic_filter IN VARCHAR2 := NULL,
fixed IN VARCHAR2 := ‘NO’,
enabled IN VARCHAR2 := ‘YES’
commit_rows IN NUMBER := 1000)
RETURN PLS_INTEGER;
You just need to specify the sqlset_name and the sqlset_owner in order to load the plans contained in the STS. It also has the default parameters fixed, set to ‘NO’ and enabled,set to ‘YES’. Two interesting attributes can be set within this function. The basic_filter attribute allows you to select only the plans that meet this filter criteria, in other words, is like a ‘where’ in a query.
basic_filter => ‘sql_text like ”select /*LOAD_STS*/%”’ orbasic_filter => ‘sql_id=”4c372tsuhtunm“‘
The commit_rows attribute, allows you to commit after the value specified, which is 1000 by default. Let’s assume that inside this STS we have 30000 plans and we want to load all of them, SPM will commit every 1000 plans to help to reduce the undo log.
Keep in mind that once you manually load plans for a specific SQL (signature), the CBO will continue capturing plans for it, even if the automatic capture is disabled. Those automatic captured plans will not be used by the CBO until you verify and evolve them.
In the next post, I’m going to show you how to evolve plans in 11g and 12c versions.
Thanks,
Alfredo
Understanding Oracle SQL Plan Management SPM – Part 2
In my previous post Understanding SQL Plan Management – Part 1, I tried to cover some basic concepts of SQL Plan Management (SPM). This post will show you the main components of SPM and how they work in the different versions of Oracle.
SQL plan management framework has three main components, plan capture, plan selection and plan evolution. These components allow administrators choose which plans should be executed by the database. Plan capture is the process of loading execution plans from different sources into the SQL management base. Plan selection is the process the database follows in order to choose the best plan available after considering many factors including SQL baselines. Plan evolution is the process of making baselines executable after verifying if any performance improvement is available.
Plan capture can be done in two forms, automatic and manual. Automatic plan capture takes place when the database initialization parameter OPTIMIZER_CAPTURE_SQL_PLAN_BASELINES is set to TRUE. Keep in mind that the default value for this parameter is FALSE. If automatic capture is enabled, the CBO will log the SQL signature of any SQL statement executed for the very first time in the database. When the SQL statement is executed for the second time it will recognize it as a repeatable statement in the database and SQL baselines are automatically created and marked as “ACCEPTED” for each repeatable SQL statement. Be careful with this feature because the baseline will be created using the execution plan of the second execution whether is optimal or not. If the CBO produces a better execution plan after the baseline is created, the plan will be stored in the SMB but not used until the plan is evolved.
Manual plan capture is the most common method to capture plans. It can be done in conjunction or instead of automatic capture for a single SQL statement or a group of statements. Plans can be manually loaded by using either DBMS_SPM package or Oracle Enterprise Manager (OEM) from four different sources. Manual loaded plans are automatically “ACCEPTED” and the CBO will continue to load plans automatically for this plans even if automatically plan capture is disabled. Plans automatically loaded after the manual load are marked as not “ACCEPTED”. You can load plans from four sources. From cursor cache, which are the active plans in memory. From SQL tuning sets, which require the SQL tuning pack or real application testing license. From stored outlines and from another Oracle database system using datapump. In order to transfer baselines from one database system to another, you must pack, load and unpack the baseline by following the below steps:
1. On the original system, create a staging table using the DBMS_SPM.CREATE_STGTAB_BASELINE procedure.
2. Pack the SQL plan baselines you want to export from the SQL management base into the staging table using the DBMS_SPM.PACK_STGTAB_BASELINE function.
3. Export the staging table into a flat file using the export command or Oracle Data Pump.
4. Transfer this flat file to the target system.
5. Import the staging table from the flat file using the import command or Oracle Data Pump.
6. Unpack the SQL plan baselines from the staging table into the SQL management base on the target system using the DBMS_SPM.UNPACK_STGTAB_BASELINE function.
The CBO calculates the execution plan every time the SQL statement is parsed (compiled) and then proceeds to execute the statement. If the OPTIMIZER_USE_SQL_PLAN_BASELINES is set to TRUE, the CBO will check if a SQL baseline exists before the plan is executed. If there is no SQL signature that matches the parsed SQL statement then the CBO will log this signature in the statement log if the automatic capture is enabled or just proceeds to execute the statement if disabled. If a signature matches the statement and a baseline doesn’t exists, it will proceed to create a plan for verification but if a baseline already exists then the baseline will be executed. If more than one “ACCEPTED” plan exists in the baseline, the CBO costs each plan for the given SQL statement and picks the one with the lowest cost. If a baseline is marked as “FIXED”, the CBO picks the lowest cost fixed plan unless all fixed plans are marked as non-reproducible.
Plan evolution, in simple terms is the process to “ACCEPT” or “REJECT” plans after verifying that performance is better or not compared with the current plan. Plan evolution as plan capture can be done automatic and manual. Automatic plan evolution is managed by the SQL tuning advisor task in 11g versions, while is managed by the SPM Evolve Advisor in 12c.
Adaptive SQL Plan Management is one of the new features of Oracle 12c. Adaptive SQL Plan Management, is just the new automatic evolve task SYS_AUTO_SPM_EVOLVE_TASK that runs in the nightly maintenance window and is enabled by default. This task ranks all unaccepted plans and runs the evolve process for them. If the plan performs 1.5x times better than the current plan in the SQL plan baseline, then the plan is automatically accepted and becomes usable by the optimizer. This ratio defined by the hidden parameter _PLAN_VERIFY_IMPROVEMENT_MARGIN and can be modified. After the evolve task is complete, a persistent report is generated with details on how the non-accepted plan perform compared to the accepted plan performance. Administrators can go back and check what plans were evolved to any point in time.
Manual plan evolution is bit different in every version of the database. In 11g release 1, is being controlled using the DBMS_SPM.ALTER_SQL_PLAN_BASELINE function and by changing the attribute_name ‘ACCEPTED’ to ‘YES’. Is the administrator’s responsibility verify that the plan is performing better than the current plan. In 11g release 2, the DBMS_SPM.EVOLVE_SQL_PLAN_BASELINE function helps the adminstrator verify if the plan performs better than the current plan and if it does, the plan is marked as “ACCEPTED”. A new SPM Evolve Advisor API is available in 12c version. Create task, execute task and report the evolve taks are part of the three step process of evolving plans. Unaccepted plans are not manually evolved when using the SPM Evolve Advisor, therfore the plan must be manually accepted using DBMS_SPM.ACCEPT_SQL_PLAN_BASELINE function.
In the next post I will show you how to use the different DBMS_SPM functions to capture and evolve plans.
Thanks,
Alfredo