Changes between Version 7 and Version 8 of UsersGuide

Timestamp:

Oct 15, 2012 5:37:41 PM (12 years ago)

Author:

Ted Faber

Comment:

--

UsersGuide

@@ -199 +199 @@
 Requested a QEMU node with more than 7 experimental interfaces.  Qemu nodes
 can only support 7 experimental interfaces.
-
-
-}}}
-
-The good news is that the container system is using qemu containers to build our experiment.  Unfortunately qemu containers only support 7 experimental interfaces, an internal limit on the number of interfaces the virtual hardware supports.  A 
+}}}
+
+The good news is that the container system is using qemu containers to build our experiment.  Unfortunately qemu containers only support 7 experimental interfaces, an internal limit on the number of interfaces the virtual hardware supports.  A [attachment:example2.tcl version of the topology with fewer satellites] will containerize without error.
+
+{{{
+$ /share/containers/containerize.py --default-container qemu DeterTest example2 ~/example2.tcl 
+Containerized experiment DeterTest/example2 successfully created!
+Access it via http://www.isi.deterlab.net//showexp.php3?pid=DeterTest&eid=example2
+}}}
+
+The qemu experiment looks much like the openvz experiment above, at this small scale.  Qemu nodes more completely emulate hardware and the kernels are independent, unlike openvz containers.  For example, a program can load kernel modules in a qemu VM, which it cannot do in an openvz container.  The qemu containers load the Ubuntu 12.04 (32 bit) distribution by default.
+
+We can also swap in the experiment using ViewOS processes, but processes cannot be manipulated from outside.  They are too lightweight to allow an ssh login, though they will run a start command.
+
+=== Mixing Containers ===
+
+Mixing containers requires the experimenter to assign container types in their topology assignment.  This is done by attaching an attribute to nodes.  The attribute is named {{{containers:node_type}}}.  If the experiment definition is in [http://fedd.isi.deterlab.net/wiki/TopDl topdl] the attribute can be attached using the [http://fedd.deterlab.net/wiki/TopdlLibrary#SharedFunctions standard topdl routines].  Attaching the attribute in ns2 is done using the DETER {{{tb-add-node-attribute}}} command.
+
+{{{
+tb-add-node-attribute $node containers:node_type openvz
+}}}
+
+That command in an ns2 topology description will set {{{node}}} to be placed in an openvz container.  Using this feature, we can modify our [attachment:example1.tcl first topology] to consist of qemu nodes and a single process container in the center.  Process nodes can have unlimited interfaces, but we cannot log into them.  The new topology file looks like this:
+
+{{{
+source tb_compat.tcl
+set ns [new Simulator]
+
+# Create the center node (named by its variable name)
+set center [$ns node]
+# The center node is a process
+tb-add-node-attribute $center containers:node_type process
+
+# Connect 10 satellites
+for { set i 0} { $i < 10 } { incr i} {
+    # Create node n-1 (tcl n($i) becomes n-$i in the experiment)
+    set n($i) [$ns node]
+    # Satellites are qemu nodes
+    tb-add-node-attribute $n($i) containers:node_type qemu
+    # Connect center to $n($i)
+    ns duplex-link $center $n($i) 100Mb 10ms DropTail
+}
+
+# Creation boilerplate
+$ns rtptoto Static
+$ns run
+}}}
+