SEARCH KEYWORD -- Key-base cache


  Special ARP Uses: Gratuitous ARP, ARP Probe, and ARP Announce

In an Ethernet environment, all data is ultimately sent in the form of a Layer 2 Ethernet Frame, which includes the Src MAC, Dst MAC, and other headers such as CRC, etc. Ethernet will then deliver the data to the destination. When we program, we often specify the IP and Port, but rarely specify the MAC address. So, how is the Frame sent out? This is done by the operating system. If the system does not know the MAC address corresponding to an IP, it will send a broadcast ARP request (since this r...

   ARP,NETWORK,LINUX     2024-11-07 20:57:26

  Understanding JavaScript closure and where it can be used

Closure The official definition of closure is: an expression (usually a function) that has many variables and is bound to an environment that includes those variables. In JavaScript, closure refers to the ability of a function to access the lexical scope in which it was defined, even after the function has been executed and left that scope. This ability is due to the fact that when a function is created, it generates a closure that includes a reference to the definition environment of the curr...

   CLOSURE,JAVASCRIPT,USAGE     2023-03-05 02:17:08

  A C++ program puzzle

Recently I came across a question asked by wang2191195 on a Chinese IT forum CSDN which asks about a C++ program puzzle. He has a code snippet which cannot be compiled. The code is:#include <cstdlib> #include <iostream> using namespace std; class Base{ public: virtual void func(){ cout << "Base::func()" << endl; } virtual int func( int num ){ cout << "Base::func( int " << num << " )" << endl; return 0; ...

   C++,Puzzle,Hide,Overload     2012-05-13 02:31:26

  OpenLDAP Proxy -- Introduction

OpenLDAP is an open source project which is intended to provide some commercial-grade, fully featured applications and development tools based on the well known Light-weight Directory Access Protocol(LDAP). Hence corporations which want to manage their user and group information can freely use these tools.  OpenLDAP provides ldap servers, ldap clients and corresponding tools to work on LDAP. The LDAP server is called slapd(Stand-alone LDAP  daemon). And it would serve as the server whi...

   META,OPENLDAP,OPENLDAP PROXY,SLAPD,SLAPD.CONF,LDAP     2017-10-28 11:20:00

  China to expand 4G network across the country

According to Xinhua news, China Mobile, the country's largest telecommunication company is expanding its commercial trials of 4G network across the country including Tibet. On Tuesday, the Tibet branch of China Mobile held a ceremony to mark the beginning of its 4G network trial in Tibet. This plan includes building new 4G base stations there and also provide support for connecting to the 4G network. In this new plan, China Mobile's high speed network services will soon benefit people living in ...

   4G,China Mobile,Tibet     2013-06-13 05:06:41

  Will PHP __autoload() function really affect performance?

IntroductionRegarding to PHP performance, the most frequently discussed is the __autoload() function. Many people say that this function will affect the performance very much, some other people say that opcode will affect __autoload() as well. So we will have some tests on these two.EnvironmentPHP 5.3.9 -- Launch under fastcgi modeNginx 1.1.12eAccelerator 0.9.6.1ScreenshotsLaunch pageeAccelerator(In php.ini) configurationFile structure(each Test file has over 6000 lines of code)Testing With e...

   PHP,__autoload(),opcode,performance     2012-05-09 11:25:26

  Consistency between Redis Cache and SQL Database

Nowadays, Redis has become one of the most popular cache solution in the Internet industry. Although relational database systems (SQL) bring many awesome properties such as ACID, the performance of the database would degrade under high load in order to maintain these properties. In order to fix this problem, many companies & websites have decided to add a cache layer between the application layer (i.e., the backend code which handles the business logic) and the storage layer (i.e., the SQL d...

   REDIS,CACHE,DATABASE     2019-07-07 08:14:16

  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

  How does JGSS read Windows native TGT credential?

MS LSA is a protected subsystem that authenticates and logs users onto the local system. The user credential is stored at the native credential cache of LSA on Windows. This kind of credential is often used to authenticate the user to the server, one of the authentication methods is Kerberos. JGSS has provided a native interface which can read the native TGT credential and use it to get the TGS of a service. But how does JGSS read the native TGT credential? Here is a sample code for reading nati...

   KERBEROS,JGSS,MS LSA,NATIVE CREDENTIAL,TGT,SESSION KEY TYPE     2015-03-25 03:42:32

  Load and execute JavaScript

When we load and execute JavaScript in a webpage, there are many points we need to care about because of its design and feature. There are two features about JavaScript execution in a browser: 1). The JavaScript codes will be executed immediately once loaded;2). When JavaScript codes are being executed, they will block the following contents (including page rendering and other resources downloading). So if there are multiple js files to be loaded, these codes will be executed sequentially. Since...

   JavaScript,async,defer,load,execute     2013-06-07 04:53:46

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