Today we discover backup and recovery products for datacenters. Cloud providers like VMWare have their own backup products such as Veeam and their vCenter platform also provides ability to take snapshots. These compete directly with third party backup products such as datadomain which is known for deduplication and commvault which is known to be a leader in VM backups. Performance and operations are affected when the backup techniques are competing against each other. Some other site replication techniques include:
Hot Backup - This means maintaining an additional site which operates in parallel to the main installation and immediately takes over in the case of the failure of the main center.
Warm Backup - This site is inactive but ready to become operational within a matter of hours.
Split Site - Two installations each somewhat smaller than a hot backup are used. In case of emergency one center can keep the organization running by performing only jobs with high priority.
Cold Backup - This is used when the recovery time is mainly affected by the need to install the infrastructure and support systems ( electricity, communications, air conditioning, etc) whereas the cost is mainly affected by the cost of the hardware.
Mutual Backup - This is a mutual agreement between two computer centers generally operated by different firms. They decide to assist each other in the case of emergency on the basis of best efforts. While this may look like it is the least expensive, but it is not efficient and particularly when both firms operate with similar peak loads and where each has a limited excess capacity.
Pooling - This is an arrangement where few members join into mutual agreement concerning a computer center, which is standing by idle to offer a service to any member suffering from interruption in its computer center. The idle computer center may use cold or warm backup. The center serves a pool of user who share the owner ship or pay a certain membership fee.
#codingquestion
You are given a Text, where all space, full stop and all punctuation mark is removed. You want to reconstruct the text by putting spaces between words.
A dict is given and following API < bool isInDect(word) > is also given.
a) Decide if the text can be converted a sentence with valid words or NOT.
b) Find how many way you can do the reconstruction of the text.
c) Find what is the minimum number of space can be used for this reconstruction.
d) For case (c) find out the indexes where you suppose to put a space.
e) Now recover the text to sentence in place .
Essentially this is the same as wordBreak problem but the first match alone may not be sufficient depending on the given dictionary.
bool wordBreak(string str, List<string> dictionary)
{
if (str.length == 0) return true;
for (int i =1; i < str.length; i++)
{
if (dictionary.contains(str.substring(0,i) && wordBreak(str.substring(i, len-i), dictionary) return true;
}
return false;
}


Question: Can we setup dedicated pooling for periodic automatic backup services of active data center virtual machines?