SEARCH KEYWORD -- /dev/null


  Resolve high CPU usage issue caused by file_get_contents in PHP

Sometimes a Linux server which runs Nginx + PHP-CGI(php-fpm) web service may experience sudden system load increase and the CPU usage is around 100% for many php-cgi processes when checking with top command. If this happens, file_get_contents may be the cause if it's used in the PHP script. In lots of web applications, normally there are lots of API requests based on HTTP. Many PHP developers like to use file_get_contents("http://example.com/") to get the API response because it's simple to...

   PHP,FILE_GET_CONTENTS,PHP-CGI     2018-11-09 21:35:00

  Reflection in Java

What is Reflection? Reflection is a feature in Java that allows a program to obtain information about itself at runtime and dynamically manipulate the properties, methods, and constructors of classes or objects. With reflection, we can instantiate objects, call methods, and set properties without knowing the exact class name beforehand. The core of the reflection mechanism is the Class object, which represents a class. The Java Virtual Machine (JVM) automatically creates this Class object when i...

   JAVA REFLECTION,TUTORIAL,FIELD,METHOD     2024-06-27 07:52:12

  A simple tutorial on GoLang connecting to Clickhouse

Go, also known as Golang, is a statically-typed, concurrent programming language created by Google. ClickHouse is a high-performance, column-oriented database management system that can be used for real-time data analysis. This tutorial will provide a deep dive into how to connect to ClickHouse from a Go program, including how to perform common database operations such as SELECT and INSERT statements. Before proceeding, it is assumed that you already have Go and ClickHouse installed on your mach...

   GOLANG,CLICKHOUSE,TUTORIAL     2023-02-11 07:05:36

  Generate signed certificate from CSR in Java

In our previous tutorial, we have explained how to generate CSR which can be sent to CA for generating a signed certificate. In this tutorial, we will explain how to generate the signed certificate from CSR in Java. We will not use an actual CA but a self-signed certificate to act as a CA certificate. Since the CSR contains the subject information where a certificate needs to be generated and signed for. The key here is to extract the subject information from the CSR and then set it as the subje...

   JAVA,CSR,SIGN CERTIFICATE     2020-10-24 07:03:17

  Popular Golang JSON libraries evaluation

JSON (Javascript Object Notation), a prevailing data exchange format, is widely used in various platforms and languages. Golang, of course, will never miss the support for JSON. And with its own standard library, such as those interfaces like the REST API from the API Service in Kubernetes, it can easily process JSON. Although Go’s library works great, we can still seek those open-source JSON libs in Github to maximize our efficiency. Then the features, performance, applicability of these ...

   FASTJSON,JSON LIB,JSON LIB COMPARISON,GO-JSON     2021-12-11 23:13:23

  Strict mode in JavaScript

1. Introduction In addition to normal mode, ECMAScript 5 includes the other mode : strict mode. It means it will make JavaScript codes execute in a more strict environment. The purposes to have strict mode are: Remove some unreasonable and parts of JavaScript syntax. Reduce some of the quirk behaviors. Remove some insecure parts of code execution. Make the execution environment more secure Improve interpret efficiency and increase the execution speed Build foundation for future JavaScript versi...

   JavaScript, Strict mode. Introduction     2013-01-17 05:00:26

  When a CA becomes untrustable

Information security has become a vital part of people's life, especially for those people who spend much time online. Tons of data are being transmitted over the internet every second. These data include user ids, passwords, credit card information etc and some of them are sensitive information which needs secure way to transmit. Hence different protocols have been developed including SSL/TLS to encrypt data transmitted over the internet. The core of these security protocols is the certifi...

   APPLE,SECURITY,GOOGLE,MOZILLA,NEWS,WOSIGN     2016-10-01 23:03:44

  Our Go Cache Library Choices

In Build a Go KV Cache from Scratch in 20 minutes, I walked you through what matters when writing a local cache, and eventually implemented one, whose performance was beaten badly by that of the popular go-cache on Github though. However, the bright side is that we can learn a lot from those excellent Github Go cache products, studying their features, applicable scenarios, and implementations, and extracting what we need. In this article, I will mainly analyze and compare the four...

   GOLANG,CACHE,GO-CACHE,BIGCACHE,GOURPCACHE     2022-04-16 07:48:11

  String.length() vs String.getBytes().length in Java

In Java, String.length() is to return the number of characters in the string, while String.getBytes().length is to return the number of bytes to represent the string with the specified encoding. By default, the encoding will be the value of system property file.encoding, the encoding name can be set manually as well by calling System.setProperty("file.encoding", "XXX"). For example, UTF-8, Cp1252. In many cases, String.length() will return the same value as String.getBytes().length, but in some ...

   Java,UTF8,String,Encoding,Sample     2015-04-01 22:22:23

  Use Java ThreadLocal with caution

According to Oracle documentation, ThreadLocal is a class provides thread-local variables. These variables differ from their normal counterparts in that each thread that accesses one (via its get or set method) has its own, independently initialized copy of the variable. ThreadLocal instances are typically private static fields in classes that wish to associate state with a thread. In short, ThreadLocal variables are variables belong to a thread, not a class or an instance of a class. One common...

   JAVA,MEMORY LEAK, THREADLOCAL     2015-11-03 07:31:57

RECENT