background process that exists in 11gr2 and functionality

Process Name	Functionality
crsd	•The CRS daemon (crsd) manages cluster resources based on configuration information that is stored in Oracle Cluster Registry (OCR) for each resource. This includes start, stop, monitor, and failover operations. The crsd process generates events when the status of a resource changes.
cssd	•Cluster Synchronization Service (CSS): Manages the cluster configuration by controlling which nodes are members of the cluster and by notifying members when a node joins or leaves the cluster. If you are using certified third-party clusterware, then CSS processes interfaces with your clusterware to manage node membership information. CSS has three separate processes: the CSS daemon (ocssd), the CSS Agent (cssdagent), and the CSS Monitor (cssdmonitor). The cssdagent process monitors the cluster and provides input/output fencing. This service formerly was provided by Oracle Process Monitor daemon (oprocd), also known as OraFenceService on Windows. A cssdagent failure results in Oracle Clusterware restarting the node.
diskmon	•Disk Monitor daemon (diskmon): Monitors and performs input/output fencing for Oracle Exadata Storage Server. As Exadata storage can be added to any Oracle RAC node at any point in time, the diskmon daemon is always started when ocssd is started.
evmd	•Event Manager (EVM): Is a background process that publishes Oracle Clusterware events
mdnsd	•Multicast domain name service (mDNS): Allows DNS requests. The mDNS process is a background process on Linux and UNIX, and a service on Windows.
gnsd	•Oracle Grid Naming Service (GNS): Is a gateway between the cluster mDNS and external DNS servers. The GNS process performs name resolution within the cluster.
ons	•Oracle Notification Service (ONS): Is a publish-and-subscribe service for communicating Fast Application Notification (FAN) events
oraagent	•oraagent: Extends clusterware to support Oracle-specific requirements and complex resources. It runs server callout scripts when FAN events occur. This process was known as RACG in Oracle Clusterware 11g Release 1 (11.1).
orarootagent	•Oracle root agent (orarootagent): Is a specialized oraagent process that helps CRSD manage resources owned by root, such as the network, and the Grid virtual IP address
oclskd	•Cluster kill daemon (oclskd): Handles instance/node evictions requests that have been escalated to CSS
gipcd	•Grid IPC daemon (gipcd): Is a helper daemon for the communications infrastructure
ctssd	•Cluster time synchronisation daemon(ctssd) to manage the time syncrhonization between nodes, rather depending on NTP

Environment Variables for a Running Process in linux

Checking  environment Variables detail for a Running Process in linux.

strings –a /proc/<pid_of_the_process>/environ

[root@joshi11 ~]# ps -ef |grep pmon
root     59844 12268  0 23:21 pts/0    00:00:00 grep pmon
oracle   62026     1  0 20:42 ?        00:00:02 asm_pmon_+ASM2
[root@joshi11 ~]# strings -a /proc/62026/environ
__CLSAGFW_TYPE_NAME=ora.mdns.type
ORA_CRS_HOME=/prod/grid/11.2.0/grid
HOSTNAME=joshi11
SHELL=/bin/bash
TERM=xterm
__CRSD_CONNECT_STR=(ADDRESS=(PROTOCOL=IPC)(KEY=OHASD_IPC_SOCKET_11))
HISTSIZE=1000
NLS_LANG=AMERICAN_AMERICA.AL32UTF8
CRF_HOME=/prod/grid/11.2.0/grid
WAS_ROOTMACRO_CALL_MADE=YES
GIPCD_PASSTHROUGH=false
SSH_TTY=/dev/pts/0
LC_ALL=
__CRSD_AGENT_NAME=/prod/grid/11.2.0/grid/bin/oraagent_oracle
__CRSD_MSG_FRAME_VERSION=2
USER=root

Script to show change in query execution

Below script just queries DBA_HIST_SQLSTAT for a given sql_id. A sql_id corresponds to a single SQL query.  

set linesize 32000
set pagesize 1000
set long 2000000000
set longchunksize 1000

select ss.sql_id,
ss.plan_hash_value,
sn.END_INTERVAL_TIME,
ss.executions_delta,
ELAPSED_TIME_DELTA/(executions_delta*1000) "Elapsed Average ms",
CPU_TIME_DELTA/(executions_delta*1000) "CPU Average ms",
IOWAIT_DELTA/(executions_delta*1000) "IO Average ms",
CLWAIT_DELTA/(executions_delta*1000) "Cluster Average ms",
APWAIT_DELTA/(executions_delta*1000) "Application Average ms",
CCWAIT_DELTA/(executions_delta*1000) "Concurrency Average ms",
BUFFER_GETS_DELTA/executions_delta "Average buffer gets",
DISK_READS_DELTA/executions_delta "Average disk reads",
ROWS_PROCESSED_DELTA/executions_delta "Average rows processed"
from DBA_HIST_SQLSTAT ss,DBA_HIST_SNAPSHOT sn
where ss.sql_id = 'bjxwm53smzfjn'
and ss.snap_id=sn.snap_id
and executions_delta > 0
and ss.INSTANCE_NUMBER=sn.INSTANCE_NUMBER
order by ss.snap_id,ss.sql_id;

SQL_ID      PLAN_HASH_VALUE END_INTERVAL_TIME EXECUTIONS_DELTA Elapsed Average ms CPU Average ms IO Average ms Cluster Average ms Application Average ms Concurrency Average ms Average buffer gets Average disk reads Average rows processed
------------- --------------- ------------------------- ---------------- ------------------ -------------- ------------- ------------------ ---------------------- ---------------------- ------------------- ------------------ ----------------------
bjxwm53smzfjn   3241932711 21-NOV-13 11.06.17.602 PM    2603 11457.6083 1242.76082    8398.43699  0 0       18.4320926   101602.754       5548.3227     24.2708413
bjxwm53smzfjn   3241932711 22-NOV-13 12.00.43.481 AM    1430 38261.3023 1765.16249    10753.5862  0 0       178.180512   140427.258      6062.37692     16.3657343
bjxwm53smzfjn   3241932711 22-NOV-13 01.00.08.144 AM    1559 62753.3383 1648.73349    18714.1897  0 0       503.047884   114864.889      5246.56062     23.0667094
bjxwm53smzfjn   3241932711 22-NOV-13 02.00.39.527 AM    1997  51748.324 1763.35454    29884.9149  0 0 108.84675   103847.485      16511.4447      25.897346
bjxwm53smzfjn   3241932711 22-NOV-13 03.00.41.453 AM    9911 5908.77018 1121.02559    4629.14669  0 0       64.4795458   91980.3728      195.806881     7.65533246
bjxwm53smzfjn   3241932711 22-NOV-13 04.00.43.330 AM    7690 12101.7682 1191.67764    10476.0536  0 0       170.186179   92665.0322      370.703771     7.87412224

In general  If the number of executions for one week over the next were different that would indicate a change in query volume.  If the per execution times were different that would indicate a change in the way each query ran.

2 node RAC Local listener parameter has auto-changed .

Today we notice One of our 2 node RAC db Local listener parameter has auto-changed  .

Application is behind firewall and for them both ports 2221(local listener) and Scan listener port(1621) is opened. So if local listener port changes to 1521, they are not able to access application.


Local_listener value we seted 2221 and it got automatically changed to  1521.

After checking all db and Cluster logfile did not find any clue how it got changed . so we raised Sr with oracle. oracle confirm this is bug .

Bug 11772838 - oraagent modifies LOCAL_LISTENER with an incorrect value, when the parameter was set in spfile (Doc ID 11772838.8)

ORA-00600: internal error code, arguments: [kcratr_nab_less_than_odr], [1], [6141], [336116], [336119], [], [], [], [], [], [], []

Today we  were a power failure causing on db server  which lead logical corruption in controlfile .
using below step i solve corruption .


as per  db alert logfile.

ORA-00600: internal error code, arguments: [kcratr_nab_less_than_odr], [1], [6141], [336116], [336119], [], [], [], [], [], [], []
Incident details in: _ora_2046_i528270.trc
Use ADRCI or Support Workbench to package the incident.
See Note 411.1 at My Oracle Support for error and packaging details.
Aborting crash recovery due to error 600
Errors in file _ora_2046.trc:
ORA-00600: internal error code, arguments: [kcratr_nab_less_than_odr], [1], [6141], [336116], [336119], [], [], [], [], [], [], []
Errors in file _ora_2046.trc:
ORA-00600: internal error code, arguments: [kcratr_nab_less_than_odr], [1], [6141], [336116], [336119], [], [], [], [], [], [], []
ORA-600 signalled during: ALTER DATABASE OPEN...
Dumping diagnostic data in directory=[cdmp_20131114231835], requested by (instance=1, osid=2046), summary=[incident=528270].
Thu Nov 14 23:19:30 2013
Sweep [inc][528270]: completed
Sweep [inc2][528270]: completed

Startup mount ;

Show parameter control_files
Note down the name of the control files name and location.
select a.member,a.group#,b.status from v$logfile a ,v$log b where a.group#=b.group# and b.status='CURRENT'

Note down the name of the redo log
Shutdown abort ;

take controlfile  file backup ,
SQL>recover database using backup controlfile until cancel ;

Enter location of redo log shown as current in Query 1 when prompted for recovery

SQL> Startup mount ;
ORACLE instance started.

Total System Global Area 4275781632 bytes
Fixed Size                  2235208 bytes
Variable Size            2516583608 bytes
Database Buffers         1744830464 bytes
Redo Buffers               12132352 bytes
Database mounted.
SQL> recover database using backup controlfile until cancel ;
ORA-00279: change 1071851209 generated at 11/14/2013 18:00:54 needed for thread
1
ORA-00289: suggestion :
/Oracle/product/product/11.2.0/dbhome_11.2.0.3/dbs/arch/1_6141_817121922.dbf
ORA-00280: change 1071851209 for thread 1 is in sequence #6141


Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
/redo1/oracle/mstq2/redo/redo01g4.log  - this was my old redo logfile  name.
Log applied.
Media recovery complete.
SQL> Alter database open resetlogs ;

Database altered.


take immediately backup of db.

history inside VIM editor

~/..viminfo store history VIM editor  history.

[oracle@joshiv~]$ vim ~/.viminfo

# This viminfo file was generated by Vim 7.0.
# You may edit it if you're careful!

# Value of 'encoding' when this file was written
*encoding=utf-8


# hlsearch on (H) or off (h):
~H
# Last Search Pattern:
~MSle0/that

# Last Substitute Search Pattern:
~MSle0~&SHELL

# Last Substitute String:
$script

# Command Line History (newest to oldest):
:q!
:wq!
:%s/SHELL/script/g
:%s/shell/script/g
:c$
:c0
:/love
:!
:.,.+1!
:1g
:!pwd
:!date
:x!
:q1
:/alter
:wq1
:qq
:/LOG_ARCHIVE_DEST_2
:1
:/ALTER
:/control
:w!
:q~!

df not showing correct free space in linux

Last week i faced below issue-

When i did “df -h” and “du -sh /Mounted_parition_name” and find some difference output.

My sysadmin say it will solve/OK after server reboot.

Did some workaround on this my own i found  below.

After removing some file because of some reason the file is in open state means it is used by some process.
And in Unix every running process has some PID.

using  "lsof |grep /Mounted_parition_name" .

After  killing those process all set. 

How to lock and unlock user in Linux like Oracle RDBMS.

(1) Command for locking SO user in linux

passwd -l user_name

(2) Command for unlocking SO user in linux :

passwd -u user_name

Nohup in linux

When we run the command with ‘nohup’ and ‘&’
so that the command should run at background even the terminal get disconnected we have to press enter key 2 times. To overcome from this problem,use the below given method.

nohup joshiv.sh > joshiv.out 2> Error.err < /dev/null &

Or

nohup command_nam > command_nam.out 2> Error.err < /dev/null &


 It will crate two file Output.out and Error.err .
 It is good tip to use, in this way we can also get to know what was the output or if there was any error.

System load average in terminal with graphical

tload is the command through which we can find the load average of
system whereas it will show the load average in terminal with graphical representation.

tload

 7.97, 7.91, 8.31 ------                                                                                                                                                                         **      **                                                                                                                                                                   ********------**                                                                                                                                                                  *********      **                                                                                                                                                           ----============------==                                                                                                                                                              *************      **                                                                                                                                                            ***************      **                                                                                                                                                           ****************------**                                                                                                                                                           ****************      **                                                                                                                                                           ================------==                                                                                                                                                           ****************      **                                                                                                                                                           ****************      **                                                                                                                                                           ****************------**                                                                                                                                                           ****************      **                                                                                                                                                           ================------==                                                                                                                                                           ****************      **                                                                                                                                                           ****************      **                                                                                                                                                                                                

Different way to edit crontab

Crontab is like a task scheduler in unix operating system.I expect you are already aware about crontab edit using crontab -e.

In this post I am sharing the tips how to edit crontab without using “crontab -e” command.

As we know to edit the crontab there is a command

crontab -u username -e

In Redhat, crontab files are located at /var/spool/cron and similarly , the crontab of user will be with the name of file.

for eg. username is joshiv ,and you can see the filename with joshiv in ls -l /var/spool/cron/joshiv

Like below way we can edit cron.

vi /var/spool/cron/joshiv

10 * * * * touch /tmp/log_`date +%F-%s`

100 DBWR processes in 12c

Oracle 12c can have up to 100 DBWR processes (named DBW0 to DBWz nad BW36 to BW99).

http://docs.oracle.com/cd/E16655_01/server.121/e17615/refrn10043.htm#REFRN10043

Is Exadata really needed ? for today market ?

Since 2 Year's i am working on  Exadata  Env. thought write something on is exadata  really needed  for today market ?-  

Consider first below point before saying anything on exadata.

The primary purpose of Exadata is to speed up full table scans. 

The speed comes from the massively parallel block elimination by applying Bloom filters. The fact remains: index blocks are searched in the SGA, Exadata speeds up the full table scan. Full table scans of large table is something that OLTP avoids like a plague. In other words, Exadata does nothing for OLTP. A good SAN like VMAX can do the same thing, using the very same elements that make Exadata fast: fast data transfer using 16GB HBA's, large IO cache on SAN itself for caching and very fast drives for faster IO. Nothing else is needed for OLTP.There is no secret sauce in the Exadata machine which would speed up OLTP.

Smart scan reduces the data sent back (filtering rows as well as columns) to DB servers, how important is that for you 

There are always more storage nodes than DB nodes,so more parallelism 

HCC is important reducing actual size of data on disk 

12c im-memory - everything cannot be kept in memory, what about persistence 

Exadata flashcache persists data when in write-back mode 

Building a reliable interconnect network - Exadata pre-built and tested

We are already processing at speeds that were unheard of 10-20 years ago. I haven't done the research lately, but I bet current servers are 1,000 times faster than they were 15 years ago. 

Business problems have grown too, but not 1,000x. 

So, why are applications slower than they were 10-12 years ago? 
as above i say A good SAN like VMAX can do the same thing as its doing for full table scan.

Here's what I'd like to say. remember the old days where database systems lived and died by the Transaction Processing Council (TPC) benchmarks? I haven't seen that very much anymore. 

Exadata would not give  you much  benefit.  You can achieve If you are  actually DBA  and well knowing  system and storage.

Let me know your experience  at joshi11.vinod@gmail.com -