at t aio wireless

Research on the Linux Native AIO asynchronous AIOhttp://rango.swoole.com/archives/282First of all, the Epoll+nonblock from a macro point of view can be called full async, but from a microscopic point of view or synchronous IO. Only after the data arrives to get the system notification, then synchronously executes recv retrieves the data, does not have the iowait.The real asynchronous IO (called AIO below) s

Some time ago, I ran mysql on the self-developed iSCSI-based SAN, And the CPU iowait was very large. Later I switched to Native AIO, which greatly improved. Here is a brief summary of the implementation of Native AIO. For databases with IO as the biggest bottleneck, native AIO is almost the best choice. It relies only on multithreading and obviously cannot solve

InnoDB started using Linux native AIO (N-AIO later) from 5.5 and said goodbye to the previous simulation method. We will analyze the native AIO architecture of InnoDB from the source code 5.6.10.InnoDB has n Io handler threads (n = 1 ibuf_io_thread + 1 log_io_thread +Innodb_read_io_threads read_io_thread + innodb_write_io_threads write_io_thread), these threads a

Introduction:The most common input/output (I/O) model in Linux is synchronous I/O. In this model, when a request is sent, the application blocks until the request is met. This is a good solution because no central processing unit (CPU) is required when calling an application waiting for the completion of I/O requests ). However, in some cases, I/O requests may need to overlap with other processes. POSIX asynchronous I/O (AIO) application interface (AP

http://my.oschina.net/bluesky0leon/blog/132361Also about Bio | NIO | AIO (Java Edition) reprinted from: Zheng-lee blogRelease time: 2013/05/21 12:56About Bio | NIO | The discussion of AIO has always been there, and sometimes it is easy to confuse, to give an explanation as to my understanding:BIO | NIO | AIO, the description of itself is based on the Java languag

constraints, the full use of CPU and memory potential, is the core content of performance optimization.And how is CPU and memory dragged down by IO? This starts with several typical IO operating modes in Java.Ii. Typical IO operation mode in Java 2.1 synchronous blocking modeThe bio-style API in Java is the pattern, for example:Socket socket =// cannot read data vow not to returnIn this mode, the most intuitive feeling is that if the IO device temporarily has no data to read, the call API will

About Bio | NIO |the discussion of AIO is always there, and sometimes it's easy to confuse, as I understand it, to give an explanation: BIO| NIO |AIO, the description of itself is based on the Java language. While describing IO, we need to start from two levels: the programming language implements the underlying fundamentals from the programming language level bio| NIO |

something else to read it.2.3 Asynchronous non-blocking modeThe AIO-style API in Java is the pattern, for example:Asynchronoussocketchannel Asynchronoussocketchannel = Getasynchronoussocketchannel (); Asynchronoussocketchannel.read (Bytebuffer.allocate (4), NULL, New CompletionhandlerThis mode of service is most in place, in addition to making programming relatively complex, almost impeccable.2.4 SummaryFor IO operations, the essential difference bet

mainly introduces the use of the asynchronous network IO API and the design of the framework, taking the TCP server as an example. First look at the new classes and interfaces to support AIO introduction: Java.nio.channels.AsynchronousChannel Marking a channel supports asynchronous IO operations. Java.nio.channels.AsynchronousServerSocketChannel ServerSocket's AIO version, creating a TCP server, bindin

Linux AIO Mechanism Linux's I/O mechanism has gone through several stages of evolution:1. synchronous blocking I/O: User processes perform I/O operations until the I/O operations are completed.2. Non-blocking I/O synchronization: the user program can set the O_NONBLOCK attribute of the file descriptor, and the I/O operation can return immediately, but it does not guarantee that the I/O operation is successful.3. asynchronous event blocking I/O: User p

Today, when using AB for stress testing, it is unintentional to discover:Requests per second:xxx [#/sec] (mean)Ab-n 5000-c http://www:8080/upload/5kb.jpg (nioserver:700 aio:400)Ab-n 5000-c http://www:8080/upload/18kb.jpg (nioserver:560 aio:360)Ab-n 2000-c http://www:8080/upload/134kb.jpg (nioserver:330 aio:300)Ab-n 2000-c http://www:8080/upload/134kb.jpg (nioserv

. If it is not blocked, it is non-blocking Io. The main improvement of Java NiO 2.0 is the introduction of asynchronous io (including files and networks). Here we mainly introduce the use of Asynchronous Network I/O APIs and the design of the framework. Take the TCP server as an example. First, let's take a look at the new classes and interfaces introduced to support AIO: Java. NiO. channels. asynchronouschannel indicates that a channel supports a

IO does not have much to do with multithreading, but NIO changes the way threads are used at the application level and solves some of the practical difficulties. AIO is also somewhat related to the asynchronous IO and the previous series. Here, in order to learn and record, also write an article to introduce NiO and AIO. 1. What is NiO NIO is the abbreviation for new I/O, which, by name, represents a new

crucial difference, the synchronization must wait or the initiative to ask whether the IO completes, then why say is blocked? Because this is done by a select system call, and the Select function itself is implemented in a blocking way, the advantage of using the Select function is that it can listen to multiple file handles at the same time (if viewed from the UNP (UNIX Net programing) perspective, Select belongs to the synchronization operation. Because the process also needs to read and writ

Reprint please indicate the source: http://blog.csdn.net/anxpp/article/details/51512200, thank you. This article will be from the traditional bio to NiO to the AIO from the shallow to the deep introduction, and enclose the complete code explanation. This example is used in the following code: The client sends a formula string to the server, and the server evaluates the result to the client. All the instructions for the code, directly as comments, embe

is complete, the application will continue to execute downward.Depending on the process above, the process of interacting with the kernel in the bio process is as follows:2. NIO (New I/O)Java supports NIO (New IO) from version 1.4, which enables non-blocking I/O. The obvious difference between nonblocking I/O and blocking I/O is that when the first system call request occurs, the thread is not blocked, but it does not do anything else, but is constantly initiating the system call request.Such a

One, look at the picture A lot of IO data on the Internet, for beginners, the more look more dizzy. According to their own understanding, summed up the comparison of bio, NIO, AIO. BIO: The thread initiates an IO request, and the thread blocks until the operation completes, regardless of whether the kernel is ready for IO operation. The following figure: NIO (reactor model): Thread initiates IO request, returns immediately; After the kernel is ready

(AIO) NIO 2.0 introduces the concept of a new asynchronous channel and provides an implementation of asynchronous file channels and asynchronous socket channels. True asynchronous non-blocking I/O when asynchronous socket channels correspond to event-driven I/O (AIO) in UNIX network programming. He does not need too much selector to poll the registered channel for asynchronous reading and writing, thus simp

Unlike setting asynchronous IO in RHEL3 described in [Note225751.1], you do not need to set aio-max-size, and Unlike setting asynchronous IO in RHEL3 described in [Note 225751.1], you do not need to set aio-max-size, and 1. First install the following necessary rpm packages with the root user # Rpm-Uvh libaio-0.3.106-3.2.x86_64.rpm# Rpm-Uvh libaio-devel-0.3.106-3.2.x86_64.rpm 2. Supporting asynchronous

This article will be from the traditional bio to NiO to the AIO from the shallow to the deep introduction, and enclose the complete code explanation. This example is used in the following code: The client sends a formula string to the server, and the server evaluates the result to the client. All the instructions for the code, directly as comments, embedded in the code, see the code is easier to understand, the code will use a calculation of the resul