Defunct processes may also be known as "zombie" processes. They do not use any system resources - CPU, memory etc. but may be seen as entries in their respective operating system process table.
Defunct processes are processes that have terminated normally, but they remain visible to the Unix/Linux operating system until the parent process reads their status. Once the status of the process has been read, the operating system removes the process entries. The reason a user may see such entries in the operating system's process table, is simply because the parent process has not read the status of the process. Orphaned defunct processes are eventually inherited by the system init process and will be removed eventually.
Users should not normally see defunct processes being retained on the operating system for a long time. For a machine hosting the Strategy Intelligence Server universal 8.x process (MSTRSvr), it is possible to sometimes see defunct multi-process database connectivity processes (M8MulPrc). The multiprocess architecture of the Intelligence Server is susceptible to the problem of defunct processes, especially under system stress. However, any defunct child processes of the Intelligence Server should be cleared with the restart of the Intelligence Server process, and the existence of these processes do not affect the Intelligence Server behaviour.
Users can reboot the machine to remove defunct entries for other processes, including a defunct Intelligence Server process itself. However these entries themselves do not use any resources and can be safely ignored.
