network and vnic qos

[Giuseppe Vallarelli]

Hi Ofri, me, Moti and Mike have been looking carefully through the design spec of the vnic profiles[0]
and lately to the network traffic shaping [1] which is very closely related.
A reason of concern is the current design of network qos table[2].

First issue is the one related to the attributes associated to the traffic shaping (either inbound
or outbound), I got the chance to talk with Michal (a libvirt developer in Brno) which confirmed me
that the only compulsory attribute is average both burst and peak are optional, also he told me that
libvirt doesn't provide any default values in case those are missing ones. Looking at missingValue()
method in [3] seems that all 3 values are compulsory.

Second issue is mostly related to the decision of creating a single table with traffic shaping
for both incoming and outgoing traffic (in table defined respectively as inbound and outbound).
Incoming and outgoing traffic are independent and practically the same. If a network admin defines
only incoming traffic, outgoing traffic attributes are nulls.

An alternative approach that we discussed is the following one: a table named simply qos
or if you prefer qos_profile with the three attributes average (not null), burst and peak and an id.
In this case after the user creates a profile, that one can be associated, as you defined in your spec,
to a vnic (and in the future to a network). I'm not sure if we need a different attribute
to specify for convenience the traffic at which the qos profile is applied (incoming/inbound, ougoing/outbound).

Cheers, Giuseppe


[0]http://www.ovirt.org/Features/Network_QoS
[1]http://www.ovirt.org/Features/Network_traffic_shaping
[2]http://gerrit.ovirt.org/#/c/16294/8/packaging/dbscripts/upgrade/03_03_0400_add_network_qos_tabel.sql
[3]http://gerrit.ovirt.org/#/c/16294/8/backend/manager/modules/bll/src/main/java/org/ovirt/engine/core/bll/qos/NetworkQoSCommandBase.java