Monthly Archives: October 2017

MRP process getting terminated with error ORA-10485

Posted on by Standard 2

If you have a Data Guard environment, where you’ve just applied a Database Bundle Patch and OJVM Patch, it’s possible that your Physical Standby can throw the following error:

Completed: ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT NODELAY
Wed Oct 11 08:11:57 2017
Media Recovery Log +RECOC1/VER1S/ARCHIVELOG/2017_10_11/thread_1_seq_18251.24912.957080425
MRP0: Background Media Recovery terminated with error 10485
Wed Oct 11 08:11:57 2017
Errors in file /u01/app/oracle/diag/rdbms/ver1s/VER1S2/trace/VER1S2_pr00_220336.trc:
ORA-10485: Real-Time Query cannot be enabled while applying migration redo.

This is because your database is “open” i.e. Active Data Guard (license option) and Managed Recovery Process is trying to apply the redo of datapatch which it can’t do when “open“.

See MOS note for more info:

MRP process getting terminated with error ORA-10485 (Doc ID 1618485.1):

“ORA-10485: Real-Time Query cannot be enabled while applying migration redo.

The Real-Time Query feature was enabled when an attempt was made to recover through migration redo generated during primary upgrades or downgrades”

The easiest solution is to restart the database as “mount” mode allowing the redo via Data Guard to apply the patch, then restart again as “open” mode:

DGMGRL> show configuration;

Configuration - ver1p

Protection Mode: MaxPerformance
 Members:
 ver1p - Primary database
 ver1s - Physical standby database
 Error: ORA-16766: Redo Apply is stopped

Fast-Start Failover: DISABLED

Configuration Status:
ERROR (status updated 37 seconds ago)

DGMGRL> show database ver1s;

Database - ver1s

Role: PHYSICAL STANDBY
 Intended State: APPLY-ON
 Transport Lag: 0 seconds (computed 0 seconds ago)
 Apply Lag: 2 hours 24 minutes 33 seconds (computed 1 second ago)
 Average Apply Rate: 99.32 MByte/s
 Real Time Query: OFF
 Instance(s):
 VER1S1
 VER1S2 (apply instance)

Database Error(s):
 ORA-16766: Redo Apply is stopped

Database Status:
ERROR

DGMGRL>

Now restart the database as “mount” mode allowing the redo via Data Guard to apply the patch:

[oracle@v1ex2dbadm01 ~]$ srvctl status database -d VER1S -v
Instance VER1S1 is running on node v1ex2dbadm01 with online services VER1_BK1,VER1_BK2,VER1_BK3,VER1_BK4. Instance status: Open,Readonly.
Instance VER1S2 is running on node v1ex2dbadm02. Instance status: Open,Readonly.
[oracle@v1ex2dbadm01 ~]$ srvctl config database -d VER1S
Database unique name: VER1S
Database name:
Oracle home: /u01/app/oracle/product/12.1.0.2/dbhome_1
Oracle user: oracle
Spfile: +DATAC1/VER1S/PARAMETERFILE/spfileVER1S.ora
Password file:
Domain:
Start options: open
Stop options: immediate
Database role: PHYSICAL_STANDBY
Management policy: AUTOMATIC
Server pools:
Disk Groups: DATAC1,RECOC1
Mount point paths:
Services: VER1_BK1,VER1_BK2,VER1_BK3,VER1_BK4
Type: RAC
Start concurrency:
Stop concurrency:
OSDBA group: dba
OSOPER group: dba
Database instances: VER1S1,VER1S2
Configured nodes: v1ex2dbadm01,v1ex2dbadm02
Database is administrator managed
[oracle@v1ex2dbadm01 ~]$ srvctl stop database -d VER1S
[oracle@v1ex2dbadm01 ~]$ srvctl start database -d VER1S -o mount

Re-check Data Guard Broker to check if the transport lag and status have cleared as expected:

DGMGRL> show database ver1s

Database - ver1s

Role: PHYSICAL STANDBY
 Intended State: APPLY-ON
 Transport Lag: 0 seconds (computed 0 seconds ago)
 Apply Lag: 0 seconds (computed 0 seconds ago)
 Average Apply Rate: 34.62 MByte/s
 Real Time Query: OFF
 Instance(s):
 VER1S1
 VER1S2 (apply instance)

Database Status:
SUCCESS

DGMGRL>

Then restart the database again as “open” mode (Active Data Guard):

[oracle@v1ex2dbadm01 ~]$ srvctl stop database -d VER1S
[oracle@v1ex2dbadm01 ~]$ srvctl start database -d VER1S
[oracle@v1ex2dbadm01 ~]$ srvctl status database -d VER1S -v
Instance VER1S1 is running on node v1ex2dbadm01 with online services VER1_BK1,VER1_BK2,VER1_BK3,VER1_BK4. Instance status: Open,Readonly.
Instance VER1S2 is running on node v1ex2dbadm02. Instance status: Open,Readonly.

Re-check Data Guard Broker to check if the “Real Time Query” is back on as expected:

DGMGRL> show configuration

Configuration - ver1p

Protection Mode: MaxPerformance
 Members:
 ver1p - Primary database
 ver1s - Physical standby database

Fast-Start Failover: DISABLED

Configuration Status:
SUCCESS (status updated 2 seconds ago)

DGMGRL> show database ver1s

Database - ver1s

Role: PHYSICAL STANDBY
 Intended State: APPLY-ON
 Transport Lag: 0 seconds (computed 0 seconds ago)
 Apply Lag: 0 seconds (computed 0 seconds ago)
 Average Apply Rate: 84.35 MByte/s
 Real Time Query: ON
 Instance(s):
 VER1S1
 VER1S2 (apply instance)

Database Status:
SUCCESS

DGMGRL>

 

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Thanks

Zed DBA (Zahid Anwar)

ODC Appreciation Day : Oracle Exadata Database Machine

Posted on by Standard 2

Those that know me well, will know about my “appreciation” of the “Oracle Exadata Database Machine“, more commonly known as “Exadata” 🙂

So this will be my contribution to ODC Appreciation Day formally known as OTN Appreciation Day, a great initiative by Tim Hall aka Oracle-Base.com.

You can see a summary of last year’s blog post here:
OTN Appreciation Day : Summary

The very first Exadata, was the V1 model, the hardware by HP and the software by Oracle.  I still remember being very excited by this in my previous employment at Auto Trader and trying very hard to convince them to get one 🙂

I, of course, became an instant fan of the brawn hardware with smart software, Oracle labelling as “Hardware and Software optimised together“.

Oracle’s partnership with HP only lasted a year with Oracle switching to Sun on the V2 model, when shortly after Oracle then brought Sun in 2010.  This is when Oracle switched from the V models to X models, with the initial models being the X2-2 (2 socket) and X2-8 (8 sockets).

I still remember this old video “Oracle Exadata. Are You Ready?” that I played at an internal Auto Trader conference which was about sharing knowledge, interesting new things, etc:

Exadata has come a long way since the initial release that was aimed at being a Data Warehouse to a Full On OLTP, Data Warehouse, mixed load, consolidation platform, etc with “record-breaking” IOPS and scan rate!

My favourite feature is the smart scan, the ability to off load data intensive SQL operations from the database servers directly into the storage servers, mitigating the need to pull lots of data from storage to database server.  Yes you can have very fast All Flash Storage, but the network to ship all this to the database server becomes the bottleneck and the compute to filter the data on the database server.  Exadata does this at the storage server meaning only the rows and columns that are directly relevant to a query are sent to the database servers.

Another one is storage indexes where the min and max values are stored of a column in 1Mb chunk in memory to allow for unnecessary I/O to be avoided when it’s known that block of data doesn’t meet the predicate condition.

I didn’t manage to convince Auto Trader, however I have since been very fortunate in my current employment at Version 1 to have worked on Exadata since 2014 from the Exadata X2-2 through to X5-2.  I do really appreciate these “Engineered Systems” for the Extreme Performance, Reliability and Availability.  The whole concept of being “Engineered” and the whole stack optimised, really works and the fact that all Exadatas are the same hardware makes you appreciate their supportability.  Even patching them with patchmgr is pretty much a doddle these days! 🙂

For more info, visit the following site:
www.Oracle.com/Exadata
https://en.wikipedia.org/wiki/Oracle_Exadata

Tuesday 10th October 2017

Happy ODC Appreciation Day! #ThanksODC #ThanksOTN 🙂

If you found this blog post useful, please like as well as follow me through my various Social Media avenues available on the sidebar and/or subscribe to this oracle blog via WordPress/e-mail.

Thanks

Zed DBA (Zahid Anwar)