Information Technology Reference
In-Depth Information
3.
Affinity (reduction of network traffic beyond a top-of-rack switch)
This plug-in module evaluates the impact of network traffic. As shown in
Figure 4, communication between VMs is classified into three types:
a.
S
(small): No network traffic is required outside of a host. VMs are
placed on the same host.
b.
M
(medium): Network traffic between hosts via a top-of-rack switch is
required when VMs are placed on different hosts exiting in the same rack.
c.
L
(large): Network traffics with inter-rack routing are required when VMs
are placed on the hosts in different racks.
Additionally, we introduced a
filling rate
to represent rack occupancy. For
each rack, the
filling rate
is given as the number of deployed VMs divided by
the total capacity (number of possible VMs) of the hosts. Note that the
number of VMs is determined by the smallest VM equivalent. When the
filling rate
exceeds the predefined threshold, this plug-in module charges
additional cost
A
. Therefore, placement of VMs on racks that are at or close to
capacity is discouraged.
4.
Repulsion
We assume that a virtual system contains at least one VM that acts as a
firewall. Typically, a firewall requires high bandwidth because all traffic to
and from associated networks pass through it. Therefore, placing multiple
VM firewalls on the same host is generally undesirable. This plug-in module
considers competition for network bandwidth as a cost.
Evaluated cost will be:
B
2
, if a firewall VM is placed with other firewall VMs
0, otherwise
Note: The value of
B
is proportional to the number of VM firewalls on the
host. We use
B
2
as an analogy of the charge repulsion.
{
6
Preliminary Evaluation
We conducted simulations to evaluate the proposed mechanism. Fujitsu ServerView
Resource Orchestrator [7] and a hardware simulator were used to construct a mock
cloud computing data center environment. The Resource Orchestrator manages all
pseudo physical resources (servers, network switches and storage) and VMs. In
addition, it manages and allocates addressing resources (MAC addresses, IP
addresses, and VLAN IDs). We have made a small modification to the Resource
Orchestrator to invoke the proposed mechanism when it receives a request to deploy a
virtual system from a user.
