4j connections

Transferred from: http://blog.chinaunix.net/xmlrpc.php?r=blog/articleuid=190176id=4234854A prefaceWhen managing a large number of connections, especially only a small number of active connections, Nginx has a relatively good CPU and RAM utilization, now is the era of multi-terminal stay online, but also to let Nginx play this advantage. In this paper, a simple test, nginx maintenance of a normal PC virtual

1, modify the user process to open the number of files limit On Linux platforms, regardless of whether you write a client program or a server-side program, the highest number of concurrent TCP connection processing is limited by the system's number of simultaneous open files for a single user process (this is because the system creates a socket handle for each TCP connection). Each socket handle is also a file handle. You can use the Ulimit command to view the number of file limits that the sys

Computer---Properties---remote settings---Check "Allow computer connections to run any version of Remote Desktop (less secure)" ... First step: Open Remote Desktop: Computer---Properties---remote settings---Check "Allow computer connections to run any version of Remote Desktop (less secure)" Step Two: Set the maximum number of Remote Desktop connections Contr

From: Zhou Ting (zhouting@cn.ibm.com), software engineer, IBM China Software Development Technology Laboratory Introduction:Many applications, such as monitoring, instant messaging, and instant quotation systems, need to send changes in the background to the client in real time without the need for the client to refresh and send requests continuously. This article first introduces and compares common "server push" Solutions, focuses on the two "server push" Solutions of comet-using HTTP persist

1. modify the number of files that can be opened by a user process on the Linux platform. whether writing a client program or a server program, during high-concurrency TCP connection processing, the maximum number of concurrent connections is limited by the number of files that the system can open for a single process (this is because the system creates a socket handle for each TCP connection, each socket handle is also a file handle ). You can use th

Steps for viewing and modifying the maximum number of connections in ORACLE Step 1: On the cmd command line, enter sqlplus Step 2: Enter the user name and password as prompted 1. view the processes and sessions Parameters SQL> show parameter processes NAME TYPE VALUE Db_writer_processes integer 1 Gcs_server_processes integer 0 Job_queue_processes integer 10 Log_archive_max_processes integer 2 Processes integer 50 SQL> show parameter sessions NAME TYPE

For example, when you use the SQLCMD utility to connect to SQL Server, you receive the following error message: Copy Code code as follows: Sqlcmd: Error: Microsoft SQL Native Client: An error occurred while establishing a connection to the server. When connecting to SQL Server 2005, default settings SQL Server does not allow remote connections This fact may cause failure. This problem may occur if SQL Server 2005 is not configu

Oracle should be familiar with how to view and set the maximum number of connections for an Oracle database. Let's go over it again. To view the current number of connections, you can use SELECT COUNT (*) from v$process;Maximum number of connections set (default is $) Select value from v$parameter where name = ' processes ';Modify the maximum number of

1. modify the number of files that can be opened by a user process On the Linux platform, whether it is a client program or a server program, during high-concurrency TCP connection processing, the maximum number of concurrent connections is limited by the number of files that the system can open for a single process (this is because the system creates a socket handle for each TCP connection, each socket handle is also a file handle ). You can use the

Welcome to reprint, reprint please indicate the source of http://blog.csdn.net/yankai0219/article/details/8208776 1. persistent connection and short connection:Persistent connection: the client establishes a connection with the server. After the connection is established, the client continues to send and receive packets. In this mode, communication connections always exist. This method is usually used for P2P communication. Short connection: the clien

1. modify the number of files that can be opened by a user process On the Linux platform, whether it is a client program or a server program, during high-concurrency TCP connection processing, the maximum number of concurrent connections is limited by the number of files that the system can open for a single process (this is because the system creates a socket handle for each TCP connection, each socket handle is also a file handle ). You can run the

Set the T-SQL statement under the maximum number of connections to configure the maximum number of concurrent user connections allowed by SQLServer. Execsp_configureshowadvancedoptions, 1execsp_configureuserconnections, the first sentence of 100 is used to display the sp_configure system stored procedure advanced options, using userconnection Set the T-SQL statement under the maximum number of

Implement TCP#!/usr/bin/env python3# -*- coding: utf-8 -*-import socket# 创建一个socket:s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)# 建立连接:s.connect((‘www.sina.com.cn‘, 80))# 发送数据:s.send(b‘GET / HTTP/1.1\r\nHost: www.sina.com.cn\r\nConnection: close\r\n\r\n‘)# 接收数据:buffer = []while True: # 每次最多接收1k字节: d = s.recv(1024) if d: buffer.append(d) else: breakdata = b‘‘.join(buffer)# 关闭连接:s.close()header, html = data.split(b‘\r\n\r\n‘, 1)print(header.decode(‘utf-8‘))# 把接收的

1.Linux Link ConceptThere are two types of Linux links, one called hard links, and the other called Symbolic links (symbolic link). By default, the LN command produces a hard link."Hard Connect"A hard connection is a connection that is made through an index node. In a Linux file system, a file saved in a disk partition, regardless of the type, assigns a number to it, called the index node number (Inode index). In Linux, multiple file names point to the same index node that exists. In general, th

When developing high-performance network programs. The Windows developers say that Iocp,linux developers will say Epoll. It is clear that Epoll is an IO multiplexing technology that can efficiently handle millions of socket handles, and is much more efficient than the previous select and poll.We used to epoll to feel pretty cool, really fast, then. Why on earth can it handle so many concurrent connections quickly?Let's recall how to use the 3 Epoll sy

1.Linux Link ConceptThere are two types of Linux links, one called hard links, and the other called Symbolic links (symbolic link). By default, the LN command produces a hard link."Hard Connect"A hard connection is a connection that is made through an index node. In a Linux file system, a file saved in a disk partition, regardless of the type, assigns a number to it, called the index node number (Inode index). In Linux, multiple file names point to the same index node that exists. In general, th

ITechSource:http://itech.cnblogs.com/ 1.Linux Link ConceptThere are two types of Linux links, one called hard link, and one is called symbolic link (symbolic). By default, the LN command produces a hard link."Hard Connect"A hard connection is a connection that is made through an index node. In a Linux file system, a file stored in a disk partition, regardless of the type, assigns a number to it, called the index node number (Inode index).In Linux. Multiple file names point to the same index node

In an HTTP application, there is a problem with server shutting down the connection for some reason, such as the timeout of keepalive, so that the server as an active shutdown will enter the Fin_wait2 state, but there is a problem with the TCP/IP protocol stack, fin_ The WAIT2 state is not timed out (unlike the time_wait state), so if the client does not shut down, the Fin_wait_2 state will remain in the system reboot, and more and more fin_wait_2 states will cause the kernel to crash.Workaround

1. Limit the number of IP connections to 80 ports to a maximum of 10, which can be customized. The code is as follows Copy Code Iptables-i input-p TCP--dport 80-m connlimit--connlimit-above 10-j DROP 2. Use the recent module to limit the number of new requests in the same IP time, recent more features please refer to: Iptables Module recent application. The code is as follows Copy Cod