wavelink avalanche

request, the host list of available services is obtained from the Service Registration Discovery Center Eureka, the host of the service instance is computed after the load balancing algorithm is calculated, and the request is forwarded, so that internally serves the external caller, or the dependency coupling between internal services turns into a dependency on Eureka.#3 gets the service from the client load Balancer Ribbon to a specific instance of the backend service after obtaining services

the container will continue to increase the direct CPU resources exhausted to 100%, the entire service is not available, the cluster environment is an avalanche. Such asThe order service is not available. png：The entire Tomcat container is not available. How Pnghystrix is threaded through thread poolingHystrix through the command mode, each type of business request is encapsulated into the corresponding command request, such as query order, Order com

is to prevent malicious request traffic, malicious attacks, and traffic from exceeding the system peak. The following ideas are implemented:1. Malicious request traffic only accesses the cache.2. For the flow through to the back-end application, consider using Nginx's limit module for processing.3. For malicious IPs, you can use Nginx deny for masking.In principle, limit the flow of traffic to the back-end weak application layer.　　3 Cut FlowIf a server hangs up, you need to cut the traffic, and

right is the middleware service layer:The services offered include: Products A/b testing of products Subscription services Recommended Services Platform Routing Service configuration Encryption A typical microservices should have a cache layer, a service layer, and a data layer.The pain point of 2.Netflix Inter-service Call failure Calls between services are subject to network latency, service failures, cal

Brief Introduction Last blog I briefly introduced the basic idea of the consistent hashing algorithm. However, the consistent hashing algorithm is also accompanied by the emergence of a new problem, that is, when a server node is dead, its task will be assigned to its next server node, then this is against the distributed system needs to meet the requirements of balance. problem Avalanche Effect Some of the data on the server will be accessed more fr

architecture is: the front-end needs to maintain multiple systems It is obvious that the client needs to maintain 5 business system addresses, and it is likely that an action needs to invoke more than 1 business systems to complete, and that there is no guarantee of transactional. The following schema appears: There is no strong association between the subsystems. The API Gateway and the various business systems invoke relationships through load balancing, and the client only needs to invoke th

National Institute of Standards and Technology, the latest standard has been updated in 2008 to FIPS pub 180-3. It prescribes the sha-1,sha-224,sha-256,sha-384, and SHA-512 these one-way hashing algorithms. sha-1,sha-224 and SHA-256 apply to messages that are not longer than 2^64 bits. SHA-384 and SHA-512 apply to messages that are not longer than 2^128 bits.Hashing AlgorithmHashing is the refinement of information, usually of a much smaller length than information, and a fixed length. A crypto

operation, as long as a junior clerk, you can achieve the article hundred cent by Baidu included. third, improve the recommended reading column update rate Baidu is included in the page, but also through the recommendation of the introduction of the continuous updating of the column to improve the weight of Baidu, so as to maximize the power of the chain. I am in the article page, set up "related news" and "buy a house common sense" two small columns, these two columns are automatically updat

This document describes the IPSec configuration between the router and the Cisco firewall. The traffic between the headquarters and the branch office uses the private IP address, when the branch's local area network user accesses the Internet, needs to carry on the address conversion. Network topology Configuration Define the traffic to the router: Access-list IPSec permit IP 10.1.1.0 255.255.255.0 10.2.2.0 255.255.255.0 !---traffic to the router does not address conversion Access-list Non

. If the two-time algorithm obtains the same signature, then it is the same?? Data. One-way encryption can be used to do data verification, if the data passive hands and feet, then the data signature is not the same. Commonly used hashing encryption methods are: MD5: Fixed-length 128-bit output feature code SHA1: Fixed-length 160-bit output feature code There are other ways, mainly reflected in the difference in the output length of the signature code

Encryption method:Symmetric encryption: Encrypt and decrypt using the same passwordPublic Key cryptography: each password appears in pairs, one for the private key (secret key) and one for the public keyOne-way encryption, hash encryption: Extracting data signatures, often used for data integrity checks1. Avalanche effect2, fixed-length outputMd5:message digest,128 fixed-length outputSha1:secure Hash algorithm,160 bit fixed length outputUseradd NAMEGr

-length output3. Avalanche effect4, non-reversibleOne-way encryption common algorithms:1, Md5:message Digest, Message Digest, 128bit fixed-length output;2, Sha1:secure hash algorthm, Secure hash algorithm, 160bit fixed-length output3, sha224:4, SHA256:5, sha384:6, sha512:Salt: Random numberDev/random: Only random numbers are returned from the entropy pool, and if the entropy pool random number is exhausted, the process is blockedDev/urrandom: First tr

secret key and public keyOne-way encryption (hashed encrypted fingerprint encryption): Extract data signatures, used for data verification characteristics: avalanche effect and fixed-length output./MD5 128-bit fixed-length output sha1:secure Hash algorithm 160-bit fixed-length outputUser Category admin: ID 0 Normal User (System user 1-499 and general user 500-60000) ID 1-65535User Group Category Admin Group General Group (System Group general Group)P

usersAdditional groups, additional groups: groups other than the default groupI. Questions:What is the security context, the permission model, and how the owner and the group are associated with the permission bit5./ETC/PASSWD---has seven fields1. Use Whatis passwd---to view a man document with several chapters2. Use the man 5 passwd---to view the file format informationA. User nameB.password---password placeholderC.uid---User's ID numberD.gid---user base Group IDE.comment---notes in detailf.ho

First, the basic knowledgeSymmetric encryption:The encryption and decryption parties use the same key to solve the data confidentiality, but the way the key is passed to the other party is not easy to implement;Public Key cryptography:Keys are paired, secret key (key) and public key (public key) must be decrypted with their corresponding private key, the public key is extracted from the private key, there is a private key to know what the public key is, but know that the public key can not know

The core Hystrix,hystrix is very good protection for interface calls, it can effectively provide the usability of the application in the multi-service dependent distributed system, and the failure application can be fused and resumed, so that the application is stable in the complex environment.http://tech.lede.com/2017/06/15/rd/server/hystrix/Hystrix can also be used for avalanche, specific reference77579794The core hystrix of Redis is used in spring

password, go to/etc/shadow to see.Five, Redhat password encryption method is MD5. (Message digest, Information Digest, 5 stands for version)Six, MD5 this encryption method, that is, one-way encryption, and there is a feature, the initial conditions of small changes, will lead to a huge change in results. Because of this butterfly effect (or avalanche effect), it makes reverse cracking so hard~.VII, take a look at the contents of the/etc/shadow file.

public key encryption, or the public key must be decrypted with a private key;Algorithms: RSA, DSA, ELGamalAdvantages and Disadvantages: The digital signature can be implemented to verify the data source, the symmetric key can be exchanged securely, time encryption can be achieved, but the corresponding large data decryption efficiency is too low, suitable for encrypting a small amount of data3, one-way hash (hash)Characteristics:1) Avalanche effect:

group to which it belongs is not specifiedBasic group: Default group for usersAdditional groups, additional groups: groups other than the default group/etc/paswd (config file)Account: Login NamePassword: passwordUID: User IDGID: Basic Group IDGECOS: NotesHome dir: Home directoryShell: User's default shell/etc/shadow (password config file)Account: Login NameEncrypted Password: encrypted passwordEncryption method:Symmetric encryption: Encrypt and decrypt using the same passwordPublic Key cryptogr

: Encrypt and decrypt using the same passwordAsymmetric encryption: Encrypt and decrypt using a pair of keysKey pair: Public key, private keyBecause the above is still not enough security, so there is a single encryptionSingle encryption: Can only encrypt, cannot decrypt, extract data signature:Its characteristics: fixed-length output, avalanche effect (a little change will cause large changes)The following 6 encryption algorithms are used in Linux: $