prometheus io

there are many connections, there will be insufficient resources. Another efficient method is to store a socket connection on the server.And then Round-Robin the list. If a socket port is read (read-only), the corresponding read operation of the socket connection is called.When data is writable on the socket port (write-ready), the corresponding write operation of the socket connection is called. If the socket connection of a port is interrupted, the corresponding destructor is called to close

Node socket. io event Usage Details, nodesocket. io The socket. io class library can not only send messages to each other, but also send events to each other through the emit method of the socket port object. In the previous event, emit said that it was used to manually trigger the event. Copy codeThe Code is as follows:Socket. emit (event, data, function (data1,

Java BASICS (20) IO streams (3) and java basics io streams Here are some of the knowledge points and code I summarized in my previous class. Most of the notes I think are very good and classic, sincerely hope that these will help those who want to learn! It is inconvenient to upload code by module. There are also many things, and they are also clear! If you need it, you can leave your email in the comments.

Http://blog.chinaunix.net/uid-25871104-id-2843472.htmlIO Space and memory spaceSpeaking of this problem, it involves hardware knowledge, X86 system, with two address space: IO Space and memory space, and RISC instruction system CPU (such as ARM, PowerPC, etc.) usually only achieve a physical address space, that is, memory space.Memory Space: Memory address range, 32-bit operating system memory space of 2 of the 32 power, that is, 4G.IO space: A X86-sp

Open file int open (const char *path, int access,int mode) FILE *fopen (Char *filename, char *mode) The difference between open and fopen: The former belongs to low-level IO, the latter is advanced IO. The former returns a file descriptor, which returns a file pointer. The former has no buffer, the latter has buffer. The former is used in conjunction with read, write, etc., the latter with Fread, fwrite a

Then draw on the theory in the UNIX Network programming Volume:The 2 main objects involved in IO operations are program processes, system cores. As an example of a read operation, when an IO read occurs, it typically goes through two steps:1, waiting for data preparation2. Copy data from the system kernel to the operation processFor example, in a read operation on the socket, step 1 waits for the network pa

Dark Horse programmer-other classes in the IO package and other classes in the io package Other classes in the IO package: 1. Print stream: provides a printing method to print data of various data types as isByte print stream PrintStreamAcceptable parameter types of constructors:(1) File object(2) String path String(3) Output byte stream OutputStream Character pr

, directly submit the command + user buffer to the kernel driver, and then return immediately. At this time, the user thread can continue to run and do other things. When you want to know the command completion status, you can use getqueuedcompletionstatus to obtain the completed request and data. Therefore, you can submit a large number of IO requests first, and then process and return them slowly. The reason why iocp is more efficient than epoll is

Basic Application of socket. io tutorial (2) socket. io tutorial Preface Socket. IO supports timely, bidirectional, and event-based communication. It can work on every platform, every browser, and every device, with the same reliability and speed. Real-time analysis: pushes data to clients, which are expressed as real-time counters, charts, or log customers.

Objective: In general operations work often encounter such a scenario, the server's IO load is very high (util in iostat), but unable to quickly locate the IO load source process and source files resulting in the inability to make the appropriate policy to solve the problem. This phenomenon is more common on MySQL, and before 5.6 (Performance_schema provides IO