• Analyzing Linux high performance network IO and reactor model


    catalogue 1、 Introduction to basic concepts 2、 Read / write process of network IO 3、 Five Linux Network IO models 3.1 blocking I / O 3.2 non blocking I / O (nonblocking IO) 3.3 multiplexing I / O (IO multiplexing) 3.4 signal driven I / O (sigio) 3.5 asynchronous IO (aio# series functions of POSIX) […]

  • Discussion on Io, condition and loop processing in Linux shell programming


    >What’s the difference between you and me? When it comes to I / O redirection, let’s first know file descriptor (FD). In most cases, the operation of the program is to process the data. Where do you read the data? And where will it be sent? This is the function of file descriptor (FD). In […]

  • Introduce Linux IO in detail


    catalogue 1. IO overview 2.Linux IO subsystem and file system read / write process VFS layer EXT2 file system layer Page cache structure Universal block layer IO scheduling layer Device driver layer 3.IO process and buffer overview High performance write file Accurately flush “buffer cache” read-ahead Standard C library buffer for IO 4. IO queue […]

  • Summary of IO method examples of go language


    type PipeWriter Copy codeThe code is as follows: type PipeWriter struct {     // contains filtered or unexported fields } (1) Func (w * pipewriter) close() error closes the pipeline. The read operation in progress when closing will return EOF. If there is still unread data in the pipeline, it can still be read normally […]

  • SQL statement to query the current database IO waiting status


    sys.dm_ io_ pending_ io_ Requests can return the Current IO pending status. For each pending I / O request in SQL server, a corresponding line is returned, followed by sys.dm_ io_ virtual_ file_ With stats, you can see which database IO has problems. select DB_NAME(database_id) as DBNAME, database_id, file_id, io_stall, io_pending_ms_ticks, scheduler_address from sys.dm_io_virtual_file_stats(null,null)i , […]

  • Vbs script for disk IO utilization monitoring (Windows)


    Core code ‘program name: btlwchk_ DiskIO.vbs Copyright (c) 2011 Guangzhou bluetechnology Incorporated.All rights reserved ‘program purpose: to monitor the IO utilization of windows host ‘creation date: 2011-08-10 ‘author information: zhangkai ‘running environment: vbs ‘processing parameters MonSubject=”DiskIO” Set Args=WScript.Arguments If (Args.Count<1) Then  Wscript.Echo MonSubject & ” -1:command line error”  WScript.Quit(3) End If strcid=Args(0) ‘get the working […]

  • The way of PHP concurrent IO programming


    Concurrent IO has always been a technical problem in server-side programming, from the earliest synchronous blocking direct fork process, to the worker process pool / thread pool, to the current asynchronous IO and cooperation. Because PHP programmers have a strong lamp framework, they know little about this kind of underlying knowledge. The purpose of this […]

  • Five I / O models of UNIX


    I / O operations are divided into two steps: (1) first copy the data from the storage medium (disk or network, etc.) to the kernel buffer, which is called data ready and can be read by the user. (2) the user application copies the kernel buffer data to the user buffer. 1. Blocking I / […]

  • Unix Network IO Model: Synchronized Asynchronization, Silly Differentiation?


    Source Blocked IO, non-blocked IO, synchronous IO, asynchronous IO, these terms believe that many friends are also in varying degrees of confusion? I was originally, what synchronous non-blocked IO, asynchronous non-blocked IO, the head is big. Later, I read them carefully.Chapter 6.2 of “UNIX Network Programming Volume Set of Connected Network API (Third Edition)” has […]

  • Analysis of IO Model – Blocking, Non-blocking, IO Multiplexing, Signal Driven, Asynchronous IO, Synchronized IO


    Recently, I saw the code of OVS user mode. When receiving the information of kernel mode, I used Epoll multiplexing mechanism. I was very puzzled about it. So I searched some information from the Internet and learned the corresponding chapters of the book “UNIX Network into Volume 1: Socket Networking API”. Although there are many […]

  • Linux Network IO Model


    Linux Network IO Model Blocking IO Model 1. The operating system recvfrom function is called when an application initiates a network IO request 2. Waiting for approval of standby datagrams in the system (access to network data: network cards copy data to the kernel) 3. Copy data from the kernel to user space, i.e. application […]

  • Five Unix I/O Models


    I/O operations are divided into two steps: (1) Copy data from storage media (disk or network, etc.) to the kernel buffer, which is called data ready and can be read by users. (2) Copy the data from the kernel buffer to the user buffer by the user application. 1. Blocking I/O Model The function recfrom […]