singlerun

Singlerun is a concept related to software development and system administration, referring to the principle of ensuring that a particular program or process can only be executed once at any given time on a system. This is often implemented to prevent data corruption, race conditions, or unintended side effects that could arise from multiple instances of the same software running concurrently.

The mechanism for achieving singlerun can vary. One common approach involves the use of lock files. When a program starts, it attempts to create a specific file in a designated location. If the file already exists, it indicates that another instance of the program is already running, and the new instance will terminate. If the file is created successfully, the program proceeds to execute and typically deletes the lock file upon completion. Another method is to use process ID (PID) files, where the process ID of the running instance is stored in a file. Subsequent instances check for the existence of this file and the validity of the PID to determine if another instance is active.

Singlerun is particularly important for applications that manage critical resources, such as databases, file systems, or network services. For example, a database server typically needs to run as a single instance to maintain data integrity. Similarly, services that bind to a specific network port should only have one instance listening on that port. The implementation of singlerun logic is often handled within the application itself or through external scripting and system management tools.