High availability and scalability in oracle RAC 11g

High availability and scalability:

* As a dba most scraiest word or scariest area is down time we need to expertise in this particular ares.
*in that down time is the test to dba capcity only we can resolve by expertise and practice comes into picture at that time we can't google how do fail over and switch over?

reason of downtime::

High Availability
*as planned down time for os level paramter or the server team doing migaration old into new hardware
Planned Down time
*Its for doing hardware or software level ex: applying patches ,Server Hardware Upgrade,Server maintenance.

Unplanned downtime:
* 1)computer failure - our server completely blast,before the computer failure data failures causes the downtime.

Types of downtime::
*storage failure- let us take harddisk is data stored its totally gone
*site failure - due to some natural disaster our production server is gone
*Human error - someone deleting the data from database
*corruption - one block or sector are corrupted in hard disk
as a dba we have to take care our database from unplanned downtime

solution for downtime:
*Data corruption - Rman Backup
*Human error - Oracle Flashback
*site error - Oracle DataGuard
*storage Failure - oracle Asm
*computer Failure - Oracle Real application Cluster
with this downtime solution provided by oracle to achieve the high availability

what is MAA?
*the MAA stands for maximum availability architecture
*the environment which have the solution given below Rman,DataGuard,Flashback,OracleAsm,Oracle Rac

For more references:


Vertical Scalability:
*Increase the hardware capacity
*The existing hardware can't able to use
*adding the resource on hardware level
*It had a limitation on RAM,CPU and HDD
*This apporach is known as scale up
*Requires less management

Horizontal scalability:
*adding new resource with existing hardware
*this approach is known as scale out
*Requires cluster management software
*The processing power will be increase
*its limited by clusterware software not in the hardware that we use

combaining HS & VS:
*Real world combines with VS & HS
*start with a very high capacity server
*Low processor,RAM & HDD
*add processor ,RAM &HDD until server capacity is reached
*scale out by adding server by implementing cluster management software

Whatis Clusterware and grid?
*In oracle 9i it reduces the issue and released the name of "CRS"
*in oracle 10g the oracle released first own Clusterware software so the compatibility issues also solved and the Clusterware software name is "Grid".

Pre-requisites:
*Working Knowledge on Linux/Unix
*Basic Understanding Of networks
*Good at oracle DBA 10g or 11g
*Minimal Knowledge of Vmware or VirtualBox

Popular posts from this blog

Error in starting the service (OracleMTSRecovery)

Image
 While i am installing the oracle 11g database i got the popup message " Error in starting the service.The service OracleMTSRecoveryService was not found " i just ignored the message and continue my installing but the installation was successful with errors, so once again i started the installation this time also i got the same error pop up and  searched on google to resolve this issue by using below steps S-1: S-2: press " Ctrl + r " then type " regedit " you 'll got this screen and  then choose " HKEY_LOCAL_MACHINE "   S-3:  Then choose " SYSTEM "  => " ControlSet001 " => " Services " => " OracleMTSRecoveryService "       S-4:                 After   choosing the " OracleMTSRecovery " we can see the " imagepath " which was mentioned below Double click the image and change the path where we are going to install the software(like be...
Read more

ORA-39000, ORA-39143 ORA- 31619 invalid dump file in datapump

Today i am tired to export  one schema (hr) from the one database  into another database  ( import schema ) so i created one directory which is called "ram" grant read and write access to  the system user ,then i started export the schema (hr) from production  while i did the export of hr schema the job was successful after that i did import schema like below expdp : C:\>expdp system/oracle directory=ram schemas=hr dumpfile=hr.dmp logfile=hr.log ...... ...... Dump file set for SYSTEM.SYS_EXPORT_SCHEMA_02 is:   C:\datapump\HR.DMP Job "SYSTEM"."SYS_EXPORT_SCHEMA_02" successfully completed at 13:23:40 impdp: C:\>impdp system/oracle directory=ram remap_schema=hr:scott dumpfile=HR.DMP logfile=hr.log it through an error like below . ORA-39001: invalid argument value ORA-39000: bad dump file specification ORA-31619: invalid dump file "C:\datapump\hr.dmp" ORA-27091: unable to queue I/O ORA-27070: async read/write failed OSD-04006: ReadFile() failu...
Read more

ORA-00439: feature not enabled: Flashback Database

Today we discuss ORA-00439: feature not enabled: Flashback Database ora error This is the test database I was performing flashback on the dummy table to deleted some rows  and tried to do the flashback above-mentioned Error S-1: SQL> flashback table hr.rg to timestamp to_timestamp('2018-04-18 12:57:00','YYYY -MM-DD HH:MI:SS'); flashback table hr.rg to timestamp to_timestamp('2018-04-18 12:57:00','YYYY-MM-D D HH:MI:SS') * ERROR at line 1: ORA-00439: feature not enabled: Flashback Table S-2: To view version of my oracle SQL> select * from V$version; BANNER -------------------------------------------------------------------------------- Oracle Database 11g Express Edition Release 11.2.0.2.0 - Production PL/SQL Release 11.2.0.2.0 - Production CORE    11.2.0.2.0      Production TNS for 32-bit Windows: Version 11.2.0.2.0 - Production NLSRTL Version 11.2.0.2.0 - Production S-3: to features of my oracle edition SQL> SELECT Parameter, Valu...
Read more