Cognos TM1 Server overview

The following figure illustrates the operations of a remote Cognos TM1 server. These operations are explained in the text that follows.

Figure 1. Operations of a remote server

• On startup, the remote server loads dimensions and cubes from the data directory into the server machine RAM. At the same time, the server opens a new transactional log file called Tm1s.log in the data directory. After the cubes are loaded, the remote server is available.
• The remote Cognos TM1 server registers itself with one or more Admin Servers so that clients can connect to the remote Cognos TM1 server.
• Client applications contact Admin Servers to locate available Cognos TM1 servers. The clients log into the Cognos TM1 servers whose data they want to access.
• Clients edit the cube data, sending the values back to the Cognos TM1 server.
• As new values are received from clients, the Cognos TM1 server writes the records to the Tm1s.log file, keeping track of every data change, including the date and time the edit occurred, and the ID of the client who made the edit.
• As the server calculates new values in response to client requests, the server stores them in memory, increasing the amount of memory used by the server.
• When the server shuts down, all records in the Tm1s.log file are saved to disk, and the transaction log file is renamed by appending a date/time stamp to it. The Tm1s.log file is saved in the server's data directory to back out data transactions. For details, see the topic "Backing Out Records from the TransactionLog” in the IBM Cognos TM1 Operation Guide.

  If the server is intentionally shut down without saving the changes, the log file is saved with a time/date stamp and the extension is changed to .rej. You can process the Tm1syyyymmddhhmmss.rej file through TurboIntegrator to recover the transactions.

• To save all changes to the data on a Cognos TM1 server at any time without shutting down the server, right-click a server in Server Explorer and Click Save Data. All records in the Tm1s.log file are immediately written to disk, the transaction log file is renamed by appending a date/time stamp to it, and a new Tm1s.log file is created to accept any subsequent edits to cube values.

  Any changes to the metadata, such as dimension definitions and cube definitions, are immediately saved to disk. The changes to the metadata are not written to the transaction log file.