• R language back test transaction: create stock return curve based on historical signals / transactions


     Original link: http://tecdat.cn/?p=23808 This article describes how to create stock curves based on historical signals / transactions. Let’s take the historical signals of mark timing and decision moose as examples to create a stock curve for this strategy. #***************************************************************** #Load signal #***************************************************************** #Extract transaction history temp = extract.table.from.webpage(txt, ‘Transaction History’, has.header = F) temp = trim(temp\[-1,2:5\])   colnames(temp) = spl(‘id,date,name,equity’)    tickers = toupper(trim(gsub(‘\\\)’,”, sapply(temp\[,’name’\], spl, ‘\\\(‘))))\[2,\] load(file=filename)     #plota(make.xts(info$equity, info$date), type=’l’) […]

  • MySQL 8.0 password management strategy (I)


    Author: Sri sakthivel Original link:https://www.percona.com/blog/… MySQL 8.0 has many improvements in password management. This article will introduce the following two features. Password reuse policy Generate random password |1 password reuse policy This policy simply means that when setting a new password, you can restrict and prohibit the use of the used password. There are two […]

  • (25) springcloud hystrix resource isolation strategy (thread and semaphore) for Java spring cloud enterprise rapid development architecture


    ​There are two resource isolation strategies of hystrix: thread pool and semaphore. Why do we need resource isolation? Recommend the source code of split architecture In a distributed system, services call each other. For example, the number of threads configured in our container (Tomcat) is 1000, service a-service R, in which the concurrency of service […]

  • Java development tool retry framework guava retrying


    preface Guava retrying GitHub address:https://github.com/rholder/guava-retrying Guava retrying is a small extension of Google’s guava library, which allows the creation of configurable retry policies for arbitrary function calls, such as function calls that talk to remote services with unstable uptime. In daily development, especially in the era of the prevalence of micro services, when we call […]

  • Add a “request lock” to the interface


    When developing back-end interfaces, we always want to simplify some non open interfaces and do not consider malicious attacks such as DDoS too much. However, when we went online, we found that some strange problems often troubled the students at the back-end, including frequent requests for the same parameters due to users’ multiple clicks on […]

  • Java thread pool Basics


    5、 Thread pool Multithreading is often used in our development. For example, in Android, due to many limitations of the main thread, some time-consuming operations such as network requests must be run in the sub thread. We often start a sub thread through the new thread, and switch to the main thread through the handler […]

  • Goosefs unified namespace | accelerating access to storage services


    01 Preface Goosefs is a distributed caching scheme launched by Tencent cloud storage team. It mainly provides a near computing data acceleration layer based on object storage cos services for data Lake business scenarios that need caching acceleration.Unified namespace is a transparent naming mechanism provided by goosefs, which can integrate a variety of different underlying […]

  • Strategic mode of design mode


    Strategy pattern belongs to behavior pattern, which is one of the most used design patterns; Its function is to encapsulate each algorithm into an independent class of specific common interface for a group of algorithms, so that they can be transformed into each other. The policy mode allows the algorithm to change without affecting the […]

  • Policy configuration of accessing bucket with Minio SDK


    Configure users to access buckets Minio is a high-performance object storage service, which is developed based on golang and can be deployed locally.It is very convenient to use it to manage the uploaded and downloaded files in your system. ​ When accessing Minio services through SDK, you usually create a service account first, and then […]

  • 9 strategies and 6 indicators on Performance Optimization for medium and high-level front-end | Netease’s four-year practice


    preface The author has been involved in project reconstruction for nearly half a year and has been widely used in the reconstruction processperformance optimizationandDesign modeTwo aspects of knowledge.performance optimizationandDesign modeBoth aspects of knowledge are high-frequency application scenarios in both work and interview. Taking advantage of this opportunity to participate in large-scale project reconstruction, the author […]

  • Chrome plug-in tutorial 5 – learn about CSP website security policy


    To understand CSP You have to know what this thing is for First, the CSP strategy XSS Cross site scripting attack This is also the most harmful and common web page security vulnerability CSP specifies which scripts and styles the web page can load and execute Mode of use first. CSP can be used in […]