Buisiness continuity (BC)
BC is an integrated & enterpriwide process that includes all activities (nternal & external to IT) that a buisiness must perform to mitigate the impact of planned & unplanned downtime.
BC entails preparing for, responding to & recovering from a system outage that adversly affects business operations.
It involves proactive measures, such as business impact analysis & risk assesments, data protection & security and reactive counter measures, such as disaster recovery & restart, to be involved in the event of a failure.
The goal of a business continuity solution is to ensure the "Information availability" operatons.
2) Information Availability :-
Information availability (IA) refers to the ability of the infrastructure to function according to business expectations during its specified time of operation.
IA ensures that people (employees, customers, supplier & partners) can access information whenever they need it.
Information availability can be defined with the help of reliability, accessibility & timelines.
This reflects a components ability to function without failure, under stated condition for a specified amount of time.
This is the state within which the required information is accessible at the right place to the right user. The period of time during which the system is in an accessible state is termed system uptime, when it is not accessible it is termed system downtime.
- Define the exact moment or the time window
a) Particular time of the day, week month & or year as specified ) during which information must be accessible.
For example, if online access to an application us required between 8:00 am & 10:00 pm each day, any distruptions to data availibility outside of this time slot are not consdered to affect timelines.
3) Disaster recovery :-
Backups can be perfoermed to address disaster recovery needs.
The backup copies are used for restarting data at alternate site when the primary site is incapacilated due to a disaster.
Based on RPO & RTO requirement, organizations use different backup strategies for disaster recovery
WHen a tape based backup method is used as a disaster recovery strategy, the backup tape media tape media is shipped & stored at an offsite location.
These tapes can be recalled for restoration at disaster recovery site.
Organizations with stringent RPO & RTO requirements use remate replication technology to replicate data to a disaster recovery site.
This allows organizations to bring up products systems online in a relatively short periods of time in the event of disaster.
4) Recovery point objective : (RPO)
This is the point in time to which system & data must be recovered after an outage.
It defines the amount of data loss a business can endure.
A large RPO signifies high tolerance to information loss in a business.
Based on the RPO, organizations plan for the minimum frequency with which a backup or replicas must be made.
For example, if the RPO is six hours, backup or replicas must be made atleast once in 6 hours.
Figure below shows various RPOS & their corresponding ideal recovery strategies.
RPO of 24 hours :-
- This ensures that backups are created on an offsite tape drive every midnight. The corresponding recovery strategy is to restore data data from the set of last backup tapes.
RPO of 1 hours :-
This ships database bags to the remote site every hour.
The corresponding recovery strategy is to recover the database at the point up the cast log shipment.