# Application modes¶

Arising from the two user groups described in Access modes, flex_extract has four different user application modes:

1. Remote (member)

In the Remote mode the user works directly on a ECMWF member-state Linux server, such as ecgate or cca/ccb. The software will be installed in the $HOME directory. The user does not need to install any of the third-party libraries mentioned in Dependencies, as ECMWF provides everything with environment modules. The module selection will be done automatically by flex_extract. 1. Gateway (member) The Gateway mode can be used if a local member-state gateway server is in place. Then, the job scripts can be submitted to the ECMWF member-state Linux server via the ECMWF web access tool ecaccess. The installation script of flex_extract must be executed on the local gateway server such that the software will be installed in the $HOME directory at the ECMWF server and that some extra setup is done in the flex_extract directory on the local gateway server. For more information about establishing a gateway server, please refer to ECMWF’s instructions on gateway server. For the Gateway mode the necessary environment has to be established which is described in Prepare gateway environment.

1. Local member

Scripts are installed and executed on a local machine, either in the current flex_extract directory or in a path given to the installation script. Under this scenario, a software environment similar to that at ECMWF is required. Additionally, web API’s have to be installed to access ECMWF server. The complete installation process is described in Local mode - dependencies.

2. Local public

Scripts are installed and executed on a local machine, either in the current flex_extract directory or in a path given to the installation script. Under this scenario, a software environment similar to that at ECMWF is required. Additionally, web API’s have to be installed to access ECMWF servers. The complete installation process is described in Local mode - dependencies. In this case, a direct registration at ECMWF is necessary and the user has to accept a specific license agreement for each dataset he/she intends to retrieve.

An overview is sketched in figure Application modes.

Application modes