ssl hashing algorithm

= 1---> represents the choice of the first host to store this key and the corresponding value.Defects:If a host is down or a host is added (it must be considered), the algorithm will result in a large number of cache failures (calculated to other hosts that do not cache the data), the database, etc. suddenly bear a huge load, it is likely to cause the DB service is not available and so on.--------------------------------------------------------------

One, the normal way of hashingBefore introducing the distributed hashing algorithm, we first understand how the ordinary hash is implemented. The Java.util.HashMap class in the JDK implements a hash table, which features: ① create hash table (HASHMAP) needs to specify the size , that is, by default create a hash table that can store how many elements, its default size is 16.② when adding elements to the Has

a . PrefaceThe consistent hash (consistent Hashing), first proposed by MIT's Karger in 1997, is primarily used to address the service shocks caused by outages and expansions in volatile distributed web systems. Now the idea of the algorithm has been widely used, and in practice has been a great development.two . Algorithm Design1. Source of the problemA service c

Consistent hashing algorithm, when I first heard the name, it felt particularly advanced. And it tends to be related to distributed systems, which, to be exact, are distributed caches.In Web services, caching is a thing between a database and a server-side program. In the site's business is not very large, generally do not need this thing, every time can be queried from the database to obtain data, but as t

algorithm is only to help us reduce the number of machines in the cache cluster increase or decrease, the cache data can be rebuilt at least. As long as the number of servers in the cache cluster changes, data hit issues inevitably occur2, for the data distribution balance problem, through the idea of virtual node to achieve a balanced distribution. Of course, the fewer cache server nodes we need, the more virtual nodes are needed to balance the load

Recently, looking at the movement target tracking data, occasionally saw the zouxy09 god of a "based on the perceptual hashing algorithm visual tracking", it is very interesting. So I went to the relevant information of the perceptual hash, found that in the field of image search is very wide application, this technology I think a bit like template matching, the core is: through the similarity of fingerprin

Consistent hashing algorithm-balance-Virtual nodeThe consistent hashing algorithm is a common algorithm in distributed systems. For example, a distributed storage system, to store data on a specific node, if the use of ordinary hash method, the data mapped to a specific node

The consistent hashing algorithm is a common algorithm in distributed systems. For example, a distributed storage system, to store data on a specific node, if the use of ordinary hash method, the data mapped to a specific node, such as Key%n,key is the data key,n is the number of machine nodes, if a machine joins or exits the cluster, then all the data map is inv

Since there is a consistent hash, there must be an inconsistent hash, why is it that no one usually says inconsistent hashing? Because the common hash is inconsistent, it is not decorated, to the consistency of the hash is special to add a description of the word decoration.Hashing is generally a large number of the mold and then dispersed into different barrels, assuming we have only two barrels, there are 2, 3, 4, 54 numbers, then the result of the

The traditional distributed algorithmBefore understanding the Redis distributed algorithm, it is better to understand the application scenario in the cache, after understanding the application scenario, then to understand the consistency hashing algorithm, it is much easier, and more can reflect the advantages of a consistent

Introduction to the Java Hash hashing algorithm-MD5 SHA-512In daily development work, we often encounter a scenario where we need a reliable and proven way to test the integrity of the data in the transmission process. One of the most common situations is when we transfer files, due to network failure or some other factors, we may have downloaded the file is incomplete, which gives us the daily development

Java Advanced (57)-Phash image registration algorithm based on perceptual hashing algorithm?? After the submission of the graduation thesis, the teacher gave himself a task: image registration, that is, to give you two images, through the system to determine whether two images are the same image. Oneself as this aspect of small white, first to go online search fo

The hashing algorithm is a cryptographic algorithm that can only be encrypted and cannot be decrypted, which converts any length of information into a fixed-length string.There are two characteristics of this string:1. Even if the input value changes only a little, the output hash value will also be poor.2. Only the exact same input value can get exactly the same

Based on previous experience, we usually use the MD5 encryption algorithm, although it can be cracked, but because of its cyclical longer, so I have been using, today learned a new encryption algorithm, secure hashing algorithm, specifically he is not the data encryption algorithm