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蚂蚁金服服务注册中心数据分片和同步方案详解 | SOFARegistry 解析

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【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> SOFAStack（ S calable O pen F inancial A rchitecture Stack）是蚂蚁金服自主研发的金融级分布式架构，包含了构建金融级云原生架构所需的各个组件，是在金融场景里锤炼出来的最佳实践。 SOFARegistry 是蚂蚁金服开源的具有承载海量服务注册和订阅能力的、高可用的服务注册中心，在支付宝/蚂蚁金服的业务发展驱动下，近十年间已经演进至第五代。本文为《剖析 | SOFARegistry 框架》第四篇，本篇作者明不二。《剖析 | SOFARegistry 框架》系列由 SOFA 团队和源码爱好者们出品，项目代号： SOFA:RegistryLab/ ，文末包含往期系列文章。 GitHub 地址： https://gitee.com/sofastack/sofa-registry 概述在前面的章节中我们已经提到，SOFARegistry 与其他服务发现领域的产品相比，最大的不同点在于支持海量数据。本章即将讲述 SOFARegistry 在支撑海量数据上的一些特性。本文将从如下几个方面进行讲解： DataServer 总体架构：对 SOFARegistry 中支持海量数据的总体架构做一个简述，讲解数据分片和同步方案中所涉及到的关键技术点；

Key-Value Database

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问题 I need to store short strings (50+ characters), and quickly look them up. At first I wanted to use SQLite for this. I created a single table with a single indexed TEXT column. Using all kinds of low-level tricks I could fill the database with 1 million strings in 10 seconds. The problem was that if the PC was rebooted, adding an additional 10.000 rows took 30 seconds, which is nowhere in line with 1M rows in 10s. The reason for this is that SQLite has to read a very large part of the existing

How to generate an Authenticode Hash in C#?

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问题 I am looking into the feasibility of generating XML files that can be imported into AppLocker. According to the post I have seen here, AppLocker generates a SHA2 Authenticode hash despite it showing SHA256 as being the hash type. I have been looking at the hash algorithms available in the System.Security.Cryptography namespace, but I cannot find one for a SHA2 Authenticode. Is this possible to do in .NET? Thanks 回答1: You can use System.Security.Cryptography.SHA256 Here is MSDN article about

Extracting data from log file into Perl hash

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问题 I have a four log files. Each log file is in the same format so let's focus on one. In each log file I have to extract information such as Computer Name and such. I won't post the log file here because it has over 46,000 lines. My main goal in the end is that, once this information is extracted, I would store it in a hash. These hashes would be later used for an insert statement into a database table. What I have done so far is this use strict; use warnings; my $filename = 'IGXLEventLog.3.17

Perl - How do I update (and access) an array stored in array stored in a hash?

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问题 Perhaps I have made this more complicated than I need it to be but I am currently trying to store an array that contains, among other things, an array inside a hash in Perl. i.e. hash -> array -> array use strict; my %DEVICE_INFORMATION = {}; #global hash sub someFunction() { my $key = 'name'; my @storage = (); #assume file was properly opened here for the foreach-loop foreach my $line (<DATA>) { if(conditional) { my @ports = (); $storage[0] = 'banana'; $storage[1] = \@ports; $storage[2] = '0

How to calculate the sha1 hash of a blob using node.js crypto

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问题 In my node.js app I would like to upload a file and calculate the sha1 . I tried the following : export function calculateHash(file, type){ const reader = new FileReader(); var hash = crypto.createHash('sha1'); hash.setEncoding('hex'); const testfile = reader.readAsDataURL(file); hash.write(testfile); hash.end(); var sha1sum = hash.read(); console.log(sha1sum); // fd.on((end) => { // hash.end(); // const test = hash.read(); // }); } The file is blob from selecting a file with a file upload

Image Hash inserting in C#

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问题 When i upload an image hash is also generated with that image i store image in db but problem is how can i store hash in database.Below is my code. private void FirstpictureBox_Click(object sender, EventArgs e) { OpenFileDialog ofd = new OpenFileDialog(); ofd.Title = "Select First Image"; ofd.Filter = "Image File(*.png;*.jpg;*.bmp;*.gif)|*.png;*.jpg;*.bmp;*.gif"; if (ofd.ShowDialog() == DialogResult.OK) { FirstpictureBox.Image = new Bitmap(ofd.FileName); byte[] imgBytes = new byte[0]; /

Convert array of hashes to array

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问题 I have an array of hashes from which I need the values of the hashes in a new array. The array of hashes look likes this, with a couple thousand of them. array = [{:code=>"404"}, {:code=>"302"}, {:code=>"200"}] I have tried to look this up but have only found out how to convert from a hash. How would I go about doing this? 回答1: a=[{:code=>"404"}, {:code=>"302"}, {:code=>"200"}] puts a.map{|x|x.values}.flatten.inspect output ["404", "302", "200"] 回答2: [{:code=>"404"}, {:code=>"302"}, {:code=>

Convert array of hashes to array

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聊聊一致性hash算法的原理

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https://mp.weixin.qq.com/s/BnErT5xrPpq76A4qUEyQCw 工程师经常使用服务器的集群来设计和实现数据缓存，他们常见的策略是： 1：不管是添加，删除和查询数据，都是先将数据的id通过hash函数生成一个hash值，记为key。 2：如果有N台机器，则会计算key%N的值，这个值就是所属机器的编号，无论是添加，删除和查询数据，都是在这台机器上操作。请分析上面的策略存在的问题，并提出解决的方案。 2 解答 1：首先来想下在什么情况下会产生问题。一般情况下，在不增加机器的情况下，产生的hash值相同，那么就会在某一台机器上操作，不会产生什么问题，但是如果增加或者删除了机器，即N变化的时候，代价就会比较高，所有的数据都需要根据id重新计算一次hash值，并通过hash值对新的机器进行重新取模操作，然后对数据进行大规模的迁移。 2：那么为了解决这些问题，我们就引入了一致性hash算法，这是一种很好的数据缓存解决方案。假设通过id生成的hash值是0到（2^32）-1 的范围，那么我们可以想象成一个闭合的圆，一个数据id计算出的hash值就是对应圆中的某一个位置，如图所示当采用一致性哈希算法，把分布式集群中新的机器加入。其原理是通过使用与对象存储一样的Hash算法将机器也映射到圈中