Modifying the explicit locations can be used to add, remove or edit an explicit location. An explicit location specifies a machine or set of machines on which you want to run a tool, together with information about how to access the machine(s) and where to run the tool on the machine(s).

Default explicit location

Taverna by default will run tools locally and for this it uses the default local explicit location. You can edit this location, but you cannot remove it.

Adding an explicit location

To add an explicit location, make sure explicit locations is in the Modify selection and then click the Add button.

This will bring up a dialog where you can specify the name and the type of the explicit location. The type corresponds to the way that Taverna will access the machine(s).

Currently, you can only add an explicit location accessed via SSH.

Taverna does not allow you to add another local explicit location

When you have entered a name and clicked OK, Taverna will bring up a window in which you can enter details of where and how to run a tool.

SSH explicit locations

When you use SSH to access a machine, you may not have the same PATH as when you log into the machine. As a result, the commands may not be readily available. You need to either check the PATH you get via SSH or use explicit paths to the commands.

You will normally only want to specify one machine and to change the host field.

The host field specifies where you want to run the tool. In this field you put either the IP address of the machine or the machine address e.g. mymachine.somewhere.org . The initial value in the dialog corresponds to using SSH to run a tool on the local machine. It is unlikely that you want to keep this value.

You must not put a prefix such as http:// before the machine address

The port field specifies the port on the machine that will be used by Taverna to talk to the machine. It is unlikely that you will need to change this field from the default value of 22.

The working directory specifies where on the machine Taverna will create the sub-directories for each call of a tool service.

You should include a trailing "/" at the end of the working directory

The link and copy commands specify what Taverna uses to limit the transfer of data. Within the fields you can use:

It is unlikely that you want to change the link or copy commands

You can remove a host from the list of machines for the explicit location. If you remove the last machine, then Taverna will assume you want to revert to running on the local machine.

You can add another host to the list of machines by clicking the Add host button. This will insert a new entry in the list of machines.

If you specify more than one machine then Taverna will attempt to run the tools on the machine where the data is. This reduces data transfer but may mean that CPU usage is not equally distributed between the machines.

Clicking Cancel will prevent any changes you have made.

Cancel does not stop the creation of the explicit location. You can, however, remove it.

Removing an explicit location

To remove an explicit location, make sure explicit locations is in the Modify selection, select the explicit location you want to remove from the list and then click the Remove button.

If any tool services are set to run at the removed location, then they will be changed to run at the default local explicit location.

If any symbolic locations point at the removed location, then they will be changed to point at the default local explicit location.

You cannot remove the default local explicit location

Editing an explicit location

To edit an explicit location, make sure explicit locations is in the Modify selection, select the explicit location you want to edit from the list and then click the Edit button.

For an SSH explicit location, this will bring up a dialog similar to that when you added the explicit location.

Editing a local explicit location

Editing the default local explicit location will bring up a dialog.
In this dialog you can specify

You should include a trailing "/" at the end of the working directory

If you are running Windows on your machine then you must specify the /c option for cmd.exe, for example "C:\Windows\system32\cmd.exe /c" . If you do not specify the /c option then the tool service will never terminate as Windows keeps cmd.exe alive.