Distributed computing#

This section describes the specific steps required to configure the HRM to run on multiple machines. In particular, we address the following setup:

  • Machine 1: runs the web server (and database) and the queue manager

  • Machine 2: runs Huygens Core

  • The data folder is not directly shared (via NFS or Samba) between the two machines.


There could be more than on processing machine running Huygens Core in your institution: set up all additional machines like Machine 2.

Public-key authentication#

Image data for deconvolution is transferred from Machine 1 to Machine 2 via secure copy (scp). For this, a specified user on Machine 2 must be created/chosen, and remote access from Machine 1 via password-less, public key authentication must be set up for this user.


For the sake of the example, we will call this specific user hrm. You can pick another user, just make sure to replace hrm with your user name in what follows.

On Machine 2, create a user with name hrm and group hrm that will be used for remote authentication and data transfer. Configure password-less, public key authentication as explained on this page. The public key is uploaded to Machine 2, whereas the private key is stored on Machine 1 for the selected user (e.g. in /home/hrm/.ssh/).

HRM configuration files#

On Machine 1, configure the HRM as usual (as in the single-server configuration) but set the following variables in $HRM_CONFIG/hrm_config.inc as shown:

$copy_images_to_huygens_server = true;
$imageProcessingIsOnQueueManager = false;
$huygens_user = "hrm"   // This is the user that will log in to Machine 2
$huygens_group = "hrm"  // And this is its group

Replace hrm with your own user name and group if different.

Register processing machines#

Log on to HRM as admin and go to Servers and GPUs ServersGPUs22x22. Register the processing servers in HRM by adding an entry for every processing machine, specifiying the absolute Huygens Core path on that machine, as well as the machine name. For details on the GPU ID field see LDAP authentication.

Data folder#

On Machine 2, create the data folder pointed at by $huygens_server_image_folder. This folder should be owned by $huygens_user (e.g. “hrm”) and have group ownership as set by $huygens_group (e.g. “hrm”).