opc connection

Database Connection Pool, database connection pool java I. Why should I use the database connection pool? Database Connection resources are very expensive, especially when accessing the database through the network. A simple physical connection causes low performance. Theref

1. Relationship between HTTP protocol and TCP/IP protocol HTTP persistent connections and short connections are essentially TCP persistent connections and short connections. HTTP is an application layer protocol. TCP is used at the transport layer and IP is used at the network layer. The IP protocol mainly solves the problem of network routing and addressing. The TCP protocol mainly solves how to transmit packets reliably on the IP layer, so that the other end of the network receives all packets

What is a long connection?In fact, a long connection is relative to the usual short connection, that is, long time to maintain the client and the server connection state.The usual short connection operation steps are:Connect-"Data transfer-" close the

Turn from: 1. TCP connection When the TCP protocol is used in network communication, before the actual read and write operation, the server and the client must establish a connection, when the read and write operation is completed, the two sides no longer need the connection when they can release the connection, the

1. The relationship between the HTTP protocol and the TCP/IP protocolLong connections and short connections to HTTP are essentially TCP long connections and short connections. HTTP belongs to the Application layer protocol, which uses the TCP protocol at the Transport Layer and IP protocol at the network layer. The IP protocol mainly solves the network routing and addressing problems, the TCP protocol mainly solves how to reliably pass the packet over the IP layer, so that all the packets sent b

[Scenario description] The client is started, and the server is started. The client initiates a connection The client sends a packet containing the four bytes of "Hutu" Client disconnection, server disconnection [Process diagram]No picture, no truth! [Socket status change diagram]No picture, no truth! Establish a connection protocol (three-way handshake) (1) the client sends a TCP packet with SYN

Database Connection Pool Druid usage instructions, database connection druid Replace it with the optimal database connection pool based on factors such as comprehensive performance, reliability, stability, scalability, and ease of use. Druid: druid-1.0.29 Database Mysql.5.6.17 Replacement target: replace C3P0 with druid Reason for replacement: 1. Performance hika

I. Two Connection Files in Linux and two methods for creating Connection Files in Linux: soft connection and hard connection, although both are connection files, but there is a big difference between the two. One is a file (or directory) similar to the shortcut function of w

I. Connection establishment of TCP ( three-time handshake )Assume that host A is running a TCP client program, and B is running a TCP server program. The TCP process at both ends is the close (off) state. a actively opens the connection, while B passively opens the connection. The TCP server process for B first creates the transport control block TCP, ready to a

1.Linux Link Concept There are two kinds of Linux links, one is called hard link (Hard link), the other is called Symbolic link (symbolic link). The ln command produces a hard link by default. The specific use is: Ln–s source file Destination file. "Hard Connection" A hard connection refers to a connection through an index node. In a Linux file system, a file

Basic Principles of connectable objects and connection points In order to provide greater interaction between the component object and the customer, the component object also needs to actively communicate with the customer. The Component Object communicates with the customer through the outgoing interface. If a component object defines one or more output interfaces, this component object is called a connectable object. The so-called outbound interfac

　The TCP creation process and the link dismantling process are created automatically by the TCP/IP protocol stack relative to the socket developer. Therefore, the developer does not need to control this process. But it is quite helpful to understand the underlying operating mechanism of TCP. And for the network protocol engineers, such as written tests, is almost necessary to test the content. So here is a detailed explanation of the two processes.TCP Packet FormatSequence Number (32-bit): Used

1. Use database connection pooling to optimize program performance L Application direct access to links disadvantage Each request requires a link to the database, and a database creation connection typically consumes relatively large resources and is created for a long time. If the site 100,000 visits a day, the database server needs to create 100,000 connections, a huge waste of database resources, and ver

1. The relationship between the HTTP protocol and the TCP/IP protocolLong connections and short connections to HTTP are essentially TCP long connections and short connections. HTTP belongs to the Application layer protocol, which uses the TCP protocol at the Transport Layer and IP protocol at the network layer. The IP protocol mainly solves the network routing and addressing problems, the TCP protocol mainly solves how to reliably pass the packet over the IP layer, so that all the packets sent b