Version 9 (modified by ibaldin, 8 years ago)


Using Flukes


Flukes is a Java-based GUI that allows an experimenter to graphically inspect the state of ORCA substrates, create request topologies, submit requests to ORCA and inspect the returned substrate information (called 'manifest'). Several key features of Flukes:

  • Graphical intuitive interface
  • Uses native ORCA interfaces and resource descriptions (NDL-OWL) for maximum flexibility, unlike other interfaces to ORCA which use GENI RSpecs and GENI AM API.
  • Allows the user to submit requests and inspect the output manifest in a graphical environment
  • Allows the user to login to provisioned resources

For more information see Flukes help. To launch Flukes, be sure Java 6 JRE is installed and double-click on this link. Flukes is a Java Webstart application, which means it will update itself every time it is launched. It also requires Internet access to operate (off-line mode is not supported).

Differences with RSpecs

ORCA natively allows the user to specify a few things not available in RSpecs

  • Various node groupings (individual nodes, node groups)
  • Permits group properties common to all nodes in a group
  • Permits ORCA-driven splitting of groups between provider domains without user input
  • Allows the user to specify images to be installed into provisioned resources based on URLs
  • Allows post-boot script templates (see section below)

Post Boot Script templates

Flukes allows a post boot script to be associated with each node or node group. Post boot scripts are the preferred way to create customized instances from a shared image. Specifically, a post boot script can contain an arbitrary script that is a executed immediately after the instance has booted.

Simple example:

   echo "Hello from post boot script"
   apt-get install my-favorite-app
   echo node1 > /etc/hostname

For added functionality, ORCA uses velocity templates to create the scripts. See the user's guide for details about Velocity.

ORCA templates follow the Velocity syntax which can be used to replace several key pieces of data that are assigned by ORCA. Specifically, there are one or more arrays that contains the IP addresses assigned to each instance. There is one array of IP addresses for each group. Each array of IP addresses is referenced using the name provided to Flukes for the group. In addition, there is a variable called $MY_ADDR_INDEX that is the index of the IP address of the current instance within its group's array of IP addresses. All arrays of IP addresses are accessible from any post boot script in the current request.

The following is an example post boot script that adds an entry to the /etc/hosts file for each of the instances in the request and sets the hostname of each instance to an appropriate value. In this particular example, the first instance is assumed to be a master node named "master" while the remaining nodes are named "worker1", "worker2", etc.. The string "Group1" was used as the group name.

   # Test script 
   echo "Hello from post boot script"
   echo $Group1.get(0) master  >> /etc/hosts 
#set ( $size = $Group1.size() - 1 )
#foreach ( $i in [1..$size] )
   echo $Group1.get($i) worker$i >> /etc/hosts
#if ( $MY_ADDR_INDEX == 0)
   echo master > /etc/hostname
   echo worker$MY_ADDR_INDEX > /etc/hostname