Today we continue discussing the hyper proxy from the paper on streaming proxy design. We saw that it maintains a data structure that keeps the threshold length, the average access duration, the access frequency F etc. The system maintains two media object lists - one premium list and one basic list. These lists help to find a victim and evict some of its segments. Then the segments of new objects are adaptively admitted by the admission policy.
There are four major modules in the Hyper Proxy caching system. These are:
1) a priority based admission policy
2) Active prefetching
3) Lazy segmentation policy
4) Differentiated replacement policy
We discuss these in detail in the next few posts.
#codingexercise
GetOddNumberRangeProductFifthRootSumEighteen (Double [] A)
{
if (A == null) return 0;
Return A.OddNumberProductFifthRootSumEighteen();
}
We will continue our discussion about the major modules in the Hyper Proxy system.
Let's begin with the cache admission system. As we mentioned before, if the media object is requested the first time, the object is then cached in full. The replacement policy is activated if there is not sufficient space. From the two lists, we look at the premium list first, we pick out an object for which there is no priority and if one such is not located, we look at one with a priority. The fully cached object is linked to the basic list and an access log is created. If the access log indicated that the object is fully cached, the access log is merely updated to handle this robustness case.
The other three major modules are Active Prefetching, Lazy segmentation policy, differentiated replacement policy.
In the active prefetching module, partially cached objects so called because they don't have all the segments in the cache are then determined to see which segments should be prefetched.
In the lazy segmentation module, the average access duration at current time instance is calculated. It is used as the length of the base segment. and then the object is segmented uniformly Then a number of segments determined by the ration threshold length over base length is retained while the rest evicted.
In the differentiated replacement policy, we give a higher priority to reduce proxy jitter, reduces the erroneous decision of the replacement and gives fair chance to the replacement segment so that they can be cached back into the proxy again based on admittance policy should media objects be accessed again.
There are four major modules in the Hyper Proxy caching system. These are:
1) a priority based admission policy
2) Active prefetching
3) Lazy segmentation policy
4) Differentiated replacement policy
We discuss these in detail in the next few posts.
#codingexercise
GetOddNumberRangeProductFifthRootSumEighteen (Double [] A)
{
if (A == null) return 0;
Return A.OddNumberProductFifthRootSumEighteen();
}
We will continue our discussion about the major modules in the Hyper Proxy system.
Let's begin with the cache admission system. As we mentioned before, if the media object is requested the first time, the object is then cached in full. The replacement policy is activated if there is not sufficient space. From the two lists, we look at the premium list first, we pick out an object for which there is no priority and if one such is not located, we look at one with a priority. The fully cached object is linked to the basic list and an access log is created. If the access log indicated that the object is fully cached, the access log is merely updated to handle this robustness case.
The other three major modules are Active Prefetching, Lazy segmentation policy, differentiated replacement policy.
In the active prefetching module, partially cached objects so called because they don't have all the segments in the cache are then determined to see which segments should be prefetched.
In the lazy segmentation module, the average access duration at current time instance is calculated. It is used as the length of the base segment. and then the object is segmented uniformly Then a number of segments determined by the ration threshold length over base length is retained while the rest evicted.
In the differentiated replacement policy, we give a higher priority to reduce proxy jitter, reduces the erroneous decision of the replacement and gives fair chance to the replacement segment so that they can be cached back into the proxy again based on admittance policy should media objects be accessed again.
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