Using Services

Introduction

To view the service section of the CARMEN portal, select the services tab in the left hand panel. This displays in the left hand panel a search box, and a tree view containing an execution log and service favourites folder. The right hand panel initially displays a word cloud of the most common service metadata terms, with links to search the service repository for services with that term.

The favourites folder contains services that you either own, have used, or have manually added it as a favourite. Initially, the favourites folder will be empty, so you can use the search panel, or the tag cloud to find suitable services and add them to your favourites.

Note that there is also a “‘Run Service’ Help” button; clicking this provides a pop-up window describing how to run that particular service and view the results. The (automatically generated) information in the help is customised for each indiviual service, based upon the service metadata.

Locating a Service

Let’s use the search facility to locate a service. Type the word “waves” into the search box and then either press the enter key, or click the magnifying glass icon. In the search results (displayed below the search box) should be a service called “Analyse Waves APS2“. Select this service, and the service details are displayed in the right hand panel. From this panel you can view the service metadata, add annotations, and run the service. You can also add the service to your favourites by clicking on the “Add Favourite” text button. Add the service to your favourites, then click on the “X” in the search box to clear the search results. If you now select the favourites folder, the “Analyse Waves APS2” service should be visible.

 Running a Service

Now we will show you how to execute a CARMEN service.  Select the “Analyse Waves APS2” service, and click on the “Run” button in the right hand panel.  This will display the input parameters panel that alows the user to set input parameters. This service requires seven input parameters; an input file, a drop-down value selection box, and five numeric values. The six values, in this case, have default values pre-set, though these can be modified if required. To set the input file, click on the “Browse for input file” button, which allows you to navigate your view of the data repository and select the appropriate input file.

For this service, we have created a pre-prepared set of inputs, so press the “Run Examples” text button. This displays a list of available examples for this service – select “Demo showing video”. The input parameter panel should now be displayed as before, but with values and files selected. Click the “NEXT” button to continue. The next panel allows you to decide where you would like the results from the service to go. A file tree of your user space is displayed, that can be navigated to determine the output folder. Options exist to allow folder creation, deletion and renaming. When you are happy with the output folder location, click “SUBMIT”. You will now receive a message stating that the service has been submitted, so press “DONE” which will take you back to the start of the process.

Viewing Progress and Results

Once the service is running, you can monitor its execution status via the service log. Open the service log and find the entry for the service. Once the service is running, a BUSY icon is displayed next to the service entry. When your service has finished the status icon will display a TICK if successful or a CROSS if there has been a problem. By clicking on the service entry the status of the service execution can be determined in the right hand panel. If successful, the service may go through five stages;

  • queued – if no execution machines are available, the service execution will be placed in a queue;
  • input staging – moving the data and the service to the execution machine;
  • running – the service code is running;
  • output staging – moving the results data to the CARMEN data repository.
  • complete – the service has finished and the data is available.

When the service has finished, expand the branch under the service log icon to view the output files. For the “Analyse Waves APS2” service there will be up to 4 output files, depending upon input parameter settings. Selecting one of the output files will display a range of user options in the right hand panel, such as download, view, metadata, etc. This service produces an MPEG video, two PNG image files, and a Matlab mat file. Selecting any of the files, then clicking “view” will automatically download the file to your local machine and open it in a client application, i.e. a media player, image viewer, or Matlab.

The output files can also be viewed from the “DATA” view (select the “Data” tab in the left hand panel, and navigating to your chosen output folder.

Service Failure

If the service fails, an entry will appear in the log, and typically two files will be available detailing the problem. Generally, a service failure is due to incorrect data or parameters, as would happen if the underlying service code were to run on a local computer. If failure occurs due to some other reason, please contact support with the service  execution information (jobID, serviceID, node, status, etc) which is available by clicking on the service execution instance in the service log.

Services with Examples

We have several service examples with pre-prepared data, that we use for demonstration purposes. The following services can be executed via the “Run Examples” option.

  • Analyse Waves APS2
  • Burst Detection – NDF