Hello!
After discover your new 12c targets you are facing target status down for MGMT targets, similar to image below?
And checking on server all looks to be ok, right?
Tag: Database
Killing Killed Session Without SPID
Hello!
Have you ever killed a session in database and the session doesn’t disappear? Or yet, you killed the SPID of the session in OS and the session still running in database, but now you cannot see the SPID?
Very weird, but it happens. First of all, let us point some interesting items:
Infiniband Error: Cable is present on Port “X” but it is polling for peer port
Facing this error? Let me guess: Ports 03, 05, 06, 08, 09 and 12 are alerting? You have a Quarter Rack? Have recently installed Exadata plugin to version 12.1.0.3 or higher?
Don’t panic!
This is probably related to Bug 15937297 : EM 12C HAS ERRORS CABLE IS PRESENT ON PORT ‘N’ BUT IT IS POLLING FOR PEER PORT. The full message might be like “Cable is present on Port 6 but it is polling for peer port. This could happen when the peer port is unplugged/disabled“.
In fact, the bug was closed as not a bug. 🙂
As part of the 12.1.0.3 Exadata plugin, the IB switch ports are now checked for non-terminated cables. So these errors ‘polling for peer port’ are the expected behavior. Once ‘polling for peer port’ is an enhanced feature of the 12.1.0.3 plugin, this explains why you most likely did not see these errors until you upgraded the OMS to 12.1.0.2 and then updated the plugins.
In Quarter Racks, the following ports 3, 5, 6, 8, 9 and 12 are usually cabled ahead of time, but not terminated. In some racks port 32 may also be unterminated. Checking for incident in OEM you might see something like this image:
More“Infiniband Error: Cable is present on Port “X” but it is polling for peer port”
RS-7445 [Serv MS leaking memory] [It will be restarted] [] [] [] [] [] [] [] [] [] []
Hello!
Having this error from cell alerthistory.log? Don’t panic!
Take a look in MOS: Exadata Storage Cell reports error RS-7445 [Serv MS Leaking Memory] (Doc ID 1954357.1). It’s related to Bug – RS-7445 [SERV MS LEAKING MEMORY].
The issue is a memory leak in the Java executable and affects systems running with JDK 7u51 or later versions. This is relevant for all versions in Release 11.2 to 12.1.
What happens is that MS process is consuming high memory (up to 2GB). Normally MS use around 1GB but because of the bug the memory allocated can grow upt to 2GB. You can check it as per example below:
[root@exaserver ~]# ps -feal|grep java 0 S root 16493 14737 0 80 0 - 15317 pipe_w 18:34 pts/0 00:00:00 grep java 0 S root 22310 27043 2 80 0 - 267080 futex_ 18:15 ? 00:00:27 /usr/java/default/bin/java -Xms256m -Xmx512m -XX:-UseLargePages -Djava.library.path=/opt/oracle/cell/cellsrv/lib -Ddisable.checkForUpdate=true -jar /opt/oracle/cell/oc4j/ms/j2ee/home/oc4j.jar -out /opt/oracle/cell/cellsrv/deploy/log/ms.lst -err /opt/oracle/cell/cellsrv/deploy/log/ms.err
Note that: 267080 * 4096 = 1143MB (1GB). If your number is higher than this, it indicates the presence of the bug.
More“RS-7445 [Serv MS leaking memory] [It will be restarted] [] [] [] [] [] [] [] [] [] []”
Converting Between SQLServer, Oracle, PostgreSQL, MySQL, Sybase and others…
Hi all!
I was asked to make a conversion from T-SQL (MSSQL) Procedure to PL/PGSQL. Regarding how boring is this task, the follow link helped me:
http://www.sqlines.com/online
I highly recommend it. The site has a commercial solution to convert all database, but some code can be converted online for free. 🙂
The conversion not fixed at all, but make a good part of the work… And all help is helpful…
More“Converting Between SQLServer, Oracle, PostgreSQL, MySQL, Sybase and others…”
HANGANALYZE Part 2
Hi!
See the first part of this post here: HANGANALIZE Part 1.
This post is just complement with a little kludge I liked…
First, let’s remmember that the hanganalyze is used when you are if some hanging in your environment, of course.
But what if you are having difficult to access the database, even with ‘/ as sysdba’?
You can create a ‘preliminary connection’ without create a session, like this:
sqlplus -prelim / as sysdba
This ‘feature’ is available since Oracle 10g, and it basically skips a session creation part (which could block) when logging on as SYSDBA.
HANGANALYZE Part 1
Hi all!
I realized I have some posts about database hangs but have no posts about hanganalyze, system state or ashdump usage. So let’s fix it. 🙂
To organize the ideas I’m going to split the subject on three posts. This first will be about hanganalyse.
See the second part of this post here: HANGANALIZE Part 2.
Ok, so let me refer the most clear Oracle words I could found:
“Hanganalyze tries to work out who is waiting for who by building wait chains, and then depending on the level will request various processes to dump their errorstack.”
This is very similar to what we can do manually through v$wait_chains. But is quicker and ‘oficial’, so let’s use! 😀
But before I show how you can do it, it’s important to mention that Oracle does not recommend you to use ‘numeric events’ without a SR (MOS), according to Note: 75713.1.
So, how to do it? Basically 2 ways:
1) ALTER SESSION SET EVENTS 'immediate trace name HANGANALYZE level LL'; OR EVENT="60 trace name HANGANALYZE level 5" 2) ORADEBUG hanganalyze LL
Upgrade your JDBC and JDK before Upgrade your Database to 12c Version!
Ok, now it’s everyone upgrading to 12c, right? Thanks God, this version was released in 2013!
But there is some things to be aware when planning an upgrade, specially regarding old applications and legacy. But pay attention! Not all of the requirements are necessary inside database. It’s the case os JDBC version requirement.
The database 12c documentation explicit mentions that JDBC versions 11.1.x and below are not supported anymore. It doesn’t mean that they don’t work, it’s only unsupported and you’ll have no assistance from MOS if you need. It’s better to avoid, right?
Anyway, if you check the JDBC support matrix, if you are in version 11.2 or below you are not supported since August/2015. So the Database 12c is helping you, that don’t have patching policy, to keep on right way. Thanks to Database 12c!
If this is your situation, I highly recommend you to upgrade the directly to JDBC version 7, the last available by now. See JDBC matrix version as:
But test! Test in you dev/test/QA environments before upgrading in Production environment!
Why? Because JDBC also have his compatibility matrix. JDBC 7, for example, demands your JDK to be at least in version 7 (released in 2011!). So, it’s needed to be at least in JDK version 6, as you can see below.
(Click in the image to access the link)
OK doke?
Some interesting links for you:
Verifying a JDBC Client Installation
What are the various supported Oracle database version vs JDBC compliant versions vs JDK version supported?
Checking the Oracle JDBC Driver Version on a Weblogic Server (by Cristóbal Soto)
Matheus.
Whats is the main characteristics/skills of a DBA? [part Osborne]
Another video post!
Almost 2 years ago I spent some time thinking about “Whats is the main characteristics/skills to be a DBA?”..
I wrote 2 posts about:
Whats is the main characteristics/skills of a DBA? [part 1]
Whats is the main characteristics/skills of a DBA? [part 2]
I found a great video with Kerry Osborne talking about what he searches in a guy (or girl) to be a great professional with Oracle… Very interesting:
I’d like to paraphrase Kerry to make my own ‘best moments summary’:
“A little bit of lazyness, a good cue and a lot of calm underpresure and keeping optmimistic.”
Have a nice week!
Compilation Impact: Object Dependencies
Hi all!
It’s not necessarily the DBA function, but how often someone of business came and ask you wich is the impact on recompiling one or other procedure?
It probably happen because the DBA usually make some magic and have a better understanding about objects relationship. It happens specially in cases there is no code governance…
So, you don’t have to handle all responsability and can switch some of that with developer, through DBA_DEPENDENCIES view.
The undertstanding is easy: The depended objects and the refered objects. If ou change the refered, all depended will be impacted by.
GREPORADB> @dependencies Enter value for owner: GREPORA Enter value for obj_name: TABLE_EXAMPLE OWNER Name TYPE DEPE REFERENCED REFERENCED_OWNER REFERENCED_NAME ------------------ ----------------------------------- ---------- ---- ---------- ------------------ ----------------------------------- GREPORA TOTALANSWEREDQUESTIONS FUNCTION HARD TABLE GREPORA TABLE_EXAMPLE GREPORA USERRESPONSESTATUS FUNCTION HARD TABLE GREPORA TABLE_EXAMPLE GREPORA VW_INPROGRESSFEEDBACKOPTS VIEW HARD TABLE GREPORA TABLE_EXAMPLE GREPORA EVENTSTARTDT FUNCTION HARD TABLE GREPORA TABLE_EXAMPLE GREPORA HAVEUSERANSWEREDANYTHING FUNCTION HARD TABLE GREPORA TABLE_EXAMPLE
Nice, hãn?
## @dependencies
col owner for a18
col name for a35
col type for a10
col referenced_owner for a18
col referenced_name for a35
col referenced_type for a10
select owner,name,type,dependency_type,referenced_type,referenced_owner,referenced_name from dba_dependencies
where referenced_owner like upper('%&owner%') and referenced_name like upper('%&OBJ_NAME%');
See ya!
Matheus.