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Note

This section is not valid for SAP systems that run on Microsoft Windows NT hosts. Central logging is not available on these platforms. Read below for details on what to watch out for on Windows NT systems.

You can configure your server so that both a central and a local log are made. You need two or more SAP instances or application servers for central logging. One system is the central system. This system collects the log data of the other instance or application server. You must execute the following steps for central logging to work:

  • Set logging parameters in every system profile

  • Start a collect process on the central application server

  • Start a send process in the central system and on every instance

Logging Processes in the Central System

A central log needs two processes: A send process and a collect process. Every instance needs a send process. The send process copies local messages from every instance to the central log.

The send process is activated automatically at certain intervals. Whenever a send process is activated it forwards all log messages that have been posted since it was last activated. After forwarding the local messages, the send process terminates to save system resources.

The intervals between activating the send process can be less than one minute or greater than 30 minutes. The intervals vary automatically depending on the logging intensity on the application server. If lots of entries have been written to the log since the last time a process was activated then the next time interval will be short.

A central instance needs both a send process and a collect process. The collect process receives messages that are transferred by the send processes of the individual instances. The collect process is activated by the communication requirements of the send process. The collect process terminates between the communication requirements.

Process Status Files

Both the send and the collect process keep a file with the extension pid . The pid file contains the operating system ID (process number) of the process. If the pid file of a processe contains -1 then the process is not allowed to run. If the pid file of a process is not available, then the process was either not started or it was canceled.

Alongside the pid file, a send process also keeps a file with the extension sta . The sta file contains the descriptor for the file that edits the send process. It also contains the byte offset that the process has already reached in the file.

Note

The byte offset is not updated for every log message that is processed.

Central Logging with Windows NT

No central logging is executed on Windows NT systems. The processes that are needed for a central log are not necessary here. To avoid warning messages that affect the central log, set the SAP system parameter rslg/collect_daemon/host in your NT system to NONE.

Use the function Start of the navigation path SysLog Next navigation step Select Next navigation step All Rem. SysLogs End of the navigation pathto read data of all instances in your SAP system. If an alert appears in the Alert Monitor, the affected instance evaluates it with the Remote SysLog function.