Distributed Mode

The report engine can be started as a daemon to which report applications can connect to process reports. One or more engines can be started on the same machine or on different machines, hence distributed mode.

To take advantage of distributed mode:
  1. Place your report design documents (.4rp) on the server where the GRE daemon runs. If your design document references images using "file: url", place these files on the same server. See Place report design documents on the daemon server.
  2. Edit the source code to reflect that distributed mode is being used. This includes providing remote connection details, handle errors, and specify the location for finished files. See Provide the remote connection details and Logging in distributed mode.
  3. Start the GRE daemon. See Start the Genero Report Engine daemon.

Place report design documents on the daemon server

Place your report design documents (.4rp) on the server running the Genero Report Engine daemon. In addition to the report design documents, ensure that the fonts, images, and printers required for the reports are available. See Configure fonts.

Start the Genero Report Engine daemon

The daemon is invoked by calling the script $GREDIR/bin/greportwriter with the “–l” option and specifying the port it listens on. For example:
greportwriter -l 6500

If the Genero Report Engine daemon resides on a different machine than the running report application, you must start the daemon with the -l portname option. The -l option listens on the specified port and for each connection attempts to read an XML document from the socket. For example: 

greportwriter -l 6500

If the Genero Report Engine daemon resides on the same machine as the running report application, or if you are using SSH port forwarding, you can optionally use the -o option. The -o option provides extra security by ensuring that the daemon accepts incoming connections only if they are local. It must be used in conjunction with the -l option, for example: 

greportwriter –l 5900 -o

Provide the remote connection details

The Genero Report Writer APIs allow you to specify the instance of Genero Report Engine that handle the report.

Logging in distributed mode

If the GREDEBUG environment variable is set, the daemon logs messages of the specified level to the file gre.log in the home directory of the user invoking the daemon.
Important: Sensitive and personal data may be written to the output. Make sure that the log output is written to files that can only be read by application administrators.