More modern HTTP daemons, such as Apache, handle requests using threads instead of spawning new processes. Denial-of-service attacks are often based on the strategy of keeping a daemon too busy to handle incoming requests. This approach was used to prevent the original process from getting too busy to service new requests, as a daemon that handles all requests by itself would make a system more vulnerable to hackers. Then, the new process would die.īy spawning a new process, the original process could go back to dormant mode to wait for other requests. The new process, a replica of the daemon, would fetch the requested content and return it to the requesting client. Earlier versions of HTTP daemons would spawn a new process to handle each request. ![]() One of the most obvious examples of a daemon is the Hypertext Transfer Protocol daemon (HTTPd), which runs on every web server, continually waiting in dormant mode until requests come in from web clients and their users. What role do daemons play in web services? Secondary daemons reset the network time on their host computer by first sending a request to the primary time daemon to find out the correct network time.Ī daemon plays the role of a server in a client-server model. A time daemon runs on each of the host computers, with one being designated as primary and all others as secondary. For example, on Linux, the Network Time Protocol ( NTP) daemon is used to measure time differences between the clock on the computer it runs on and those of all other computers on the network. ![]() ![]() Many Unix or Linux utility programs run as daemons. The daemon program is alerted to the request by the operating system (OS), and it either responds to the request itself or forwards the request to another program or process as appropriate.Ĭommon daemon processes include print spoolers, email handlers and other programs that manage administrative tasks. In computing, a daemon (pronounced DEE-muhn) is a program that runs continuously as a background process and wakes up to handle periodic service requests, which often come from remote processes.
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