Welcome to a course on dealing with attacks or how to reduce losses
the topic is important as in the majority of cases I've encountered a company's security policies that
relate to recovering from attacks.
If there's any policy at all look more or less like in the picture below as you probably suspect this
is not a recommended security procedure.
This topic is relevant because the first question an I.T. staffer or any other specialists responsible
for computer security will be asked should not be a variation of how could this have happened.
We know from the previous modules that attacks are simply a matter of time a better question is what
resources have been or could have been accessed by attackers.
You can also ask about the data that has been read or modified in about the duration of time that the
attackers spent in the system.
If a person whose task is to care for a system security can answer these questions it's a sign that
they are in fact to blame for the attack.
Past experience shows that the policies that deal with recovery procedures after an attack is detected
should be designed by the most experienced member of the team
policy testing on the other hand should be carried out by the least experienced employees attacks are
not launched.
Only one the most skillful I.T. staff member is around.
Usually it's the other way around.
Any person who is currently at work must be able to carry out intentional counter actions.
It's a lot easier to deal with attacks if there's a security policy available that has been proved and
is effective.
Let's start with the methods for ensuring that the services provided by a computer system wouldn't have
to be automatically shut down.
Any small failure or attack can't result in the service down time.
Let's first take a look at the state law services for example web servers and reports servers
with these services.
It's irrelevant which copy of a given service user is connecting to
balancing where bloat is essential in this situation.
We should implement a solution that will redirect user queries to different servers in an invisible
and transparent manner.
The services that provide a specific service need to be duplicated so there's more than one server.
If that's the case a failure shut down or other unexpected event that will occur and one server won't
change the availability of service from a user standpoint.
It will probably affect the performance of a service while there'd be some steps to be taken.
The computer system will still be up
and additional benefit for this solution is relieving the performance of the entire service.
Redirecting every second query to a different server helps not only decrease the potential system failure
frequency and improve the security but also to lower service load
in this solution.
Each server that provides a service stores its own data backup copy its own website backup or its own
reports backup and so on.
This means that while recovering data after attacks or while mitigating the effects of attacks will
need to synchronize the data data volumes are often high.
So there is a necessity for allowing for a sufficient period of time for the secret ization to complete
thanks to this solution.
However we'll have a system backup prepared in case there's a need for restoring it on a different node
and alternative solution for load balancing is deploying fell over cluster's.
This is a standard approach that is implemented in the operating system level.
The solution involves creating a virtual computer made up from more than one node.
A node is a physical computer
nodes are basically classified as passive very active.
The respective names represent the role the node has and the fail over cluster architecture.
An active node is a no to what users connect and which also receives all queries from users.
A passive node is a node that doesn't manage queries.
Fell over cluster's don't enhance the performance or availability of the entire solution.