схема базы данных Open_vSwitch (Open_vSwitch database schema)
QoS TABLE
Quality of Service (QoS) configuration for each Port that
references it.
Summary:
type string
queues map of integer-Queue pairs, key in
range 0 to 4,294,967,295
Configuration for linux-htb and linux-hfsc:
other_config : max-rate optional string, containing an
integer
Configuration for egress-policer QoS:
other_config : cir optional string, containing an
integer
other_config : cbs optional string, containing an
integer
other_config : eir optional string, containing an
integer
other_config : ebs optional string, containing an
integer
Configuration for linux-sfq:
other_config : perturb optional string, containing an
integer
other_config : quantum optional string, containing an
integer
Configuration for linux-netem:
other_config : latency optional string, containing an
integer
other_config : limit optional string, containing an
integer
other_config : loss optional string, containing an
integer
Common Columns:
other_config map of string-string pairs
external_ids map of string-string pairs
Details:
type: string
The type of QoS to implement. The currently defined types
are listed below:
linux-htb
Linux ``hierarchy token bucket'' classifier. See
tc-htb(8) (also at
http://linux.die.net/man/8/tc-htb ) and the HTB
manual
(http://luxik.cdi.cz/~devik/qos/htb/manual/userg.htm )
for information on how this classifier works and
how to configure it.
linux-hfsc
Linux "Hierarchical Fair Service Curve" classifier.
See http://linux-ip.net/articles/hfsc.en/ for
information on how this classifier works.
linux-sfq
Linux ``Stochastic Fairness Queueing'' classifier.
See tc-sfq(8) (also at
http://linux.die.net/man/8/tc-sfq ) for information
on how this classifier works.
linux-codel
Linux ``Controlled Delay'' classifier. See
tc-codel(8) (also at
http://man7.org/linux/man-pages/man8/tc-codel.8.html )
for information on how this classifier works.
linux-fq_codel
Linux ``Fair Queuing with Controlled Delay''
classifier. See tc-fq_codel(8) (also at
http://man7.org/linux/man-pages/man8/tc-fq_codel.8.html )
for information on how this classifier works.
linux-netem
Linux ``Network Emulator'' classifier. See
tc-netem(8) (also at
http://man7.org/linux/man-pages/man8/tc-netem.8.html )
for information on how this classifier works.
linux-noop
Linux ``No operation.'' By default, Open vSwitch
manages quality of service on all of its configured
ports. This can be helpful, but sometimes
administrators prefer to use other software to
manage QoS. This type prevents Open vSwitch from
changing the QoS configuration for a port.
egress-policer
A DPDK egress policer algorithm using the DPDK
rte_meter library. The rte_meter library provides
an implementation which allows the metering and
policing of traffic. The implementation in OVS
essentially creates a single token bucket used to
police traffic. It should be noted that when the
rte_meter is configured as part of QoS there will
be a performance overhead as the rte_meter itself
will consume CPU cycles in order to police traffic.
These CPU cycles ordinarily are used for packet
proccessing. As such the drop in performance will
be noticed in terms of overall aggregate traffic
throughput.
trtcm-policer
A DPDK egress policer algorithm using RFC 4115's
Two-Rate, Three-Color marker. It's a two-level
hierarchical policer which first does a color-blind
marking of the traffic at the queue level, followed
by a color-aware marking at the port level. At the
end traffic marked as Green or Yellow is forwarded,
Red is dropped. For details on how traffic is
marked, see RFC 4115. If the ``default queue'', 0,
is not configured it's automatically created with
the same other_config values as the physical port.
queues: map of integer-Queue pairs, key in range 0 to
4,294,967,295
A map from queue numbers to Queue records. The supported
range of queue numbers depend on type. The queue numbers
are the same as the queue_id used in OpenFlow in struct
ofp_action_enqueue and other structures.
Queue 0 is the ``default queue.'' It is used by OpenFlow
output actions when no specific queue has been set. When
no configuration for queue 0 is present, it is
automatically configured as if a Queue record with empty
dscp and other_config columns had been specified. (Before
version 1.6, Open vSwitch would leave queue 0 unconfigured
in this case. With some queuing disciplines, this dropped
all packets destined for the default queue.)
Configuration for linux-htb and linux-hfsc:
The linux-htb and linux-hfsc classes support the following key-
value pair:
other_config : max-rate: optional string, containing an integer
Maximum rate shared by all queued traffic, in bit/s.
Optional. If not specified, for physical interfaces, the
default is the link rate. For other interfaces or if the
link rate cannot be determined, the default is currently
100 Mbps.
Configuration for egress-policer QoS:
QoS type egress-policer provides egress policing for userspace
port types with DPDK. It has the following key-value pairs
defined.
other_config : cir: optional string, containing an integer
The Committed Information Rate (CIR) is measured in bytes
of IP packets per second, i.e. it includes the IP header,
but not link specific (e.g. Ethernet) headers. This
represents the bytes per second rate at which the token
bucket will be updated. The cir value is calculated by
(pps x packet data size). For example assuming a user
wishes to limit a stream consisting of 64 byte packets to
1 million packets per second the CIR would be set to to to
46000000. This value can be broken into '1,000,000 x 46'.
Where 1,000,000 is the policing rate for the number of
packets per second and 46 represents the size of the
packet data for a 64 bytes IP packet without 14 bytes
Ethernet and 4 bytes FCS header.
other_config : cbs: optional string, containing an integer
The Committed Burst Size (CBS) is measured in bytes and
represents a token bucket. At a minimum this value should
be be set to the expected largest size packet in the
traffic stream. In practice larger values may be used to
increase the size of the token bucket. If a packet can be
transmitted then the cbs will be decremented by the number
of bytes/tokens of the packet. If there are not enough
tokens in the cbs bucket the packet will be dropped.
other_config : eir: optional string, containing an integer
The Excess Information Rate (EIR) is measured in bytes of
IP packets per second, i.e. it includes the IP header, but
not link specific (e.g. Ethernet) headers. This represents
the bytes per second rate at which the token bucket will
be updated. The eir value is calculated by (pps x packet
data size). For example assuming a user wishes to limit a
stream consisting of 64 byte packets to 1 million packets
per second the EIR would be set to to to 46000000. This
value can be broken into '1,000,000 x 46'. Where 1,000,000
is the policing rate for the number of packets per second
and 46 represents the size of the packet data for a 64
bytes IP packet without 14 bytes Ethernet and 4 bytes FCS
header.
other_config : ebs: optional string, containing an integer
The Excess Burst Size (EBS) is measured in bytes and
represents a token bucket. At a minimum this value should
be be set to the expected largest size packet in the
traffic stream. In practice larger values may be used to
increase the size of the token bucket. If a packet can be
transmitted then the ebs will be decremented by the number
of bytes/tokens of the packet. If there are not enough
tokens in the cbs bucket the packet might be dropped.
Configuration for linux-sfq:
The linux-sfq QoS supports the following key-value pairs:
other_config : perturb: optional string, containing an integer
Number of seconds between consecutive perturbations in
hashing algorithm. Different flows can end up in the same
hash bucket causing unfairness. Perturbation's goal is to
remove possible unfairness. The default and recommended
value is 10. Too low a value is discouraged because each
perturbation can cause packet reordering.
other_config : quantum: optional string, containing an integer
Number of bytes linux-sfq QoS can dequeue in one turn in
round-robin from one flow. The default and recommended
value is equal to interface's MTU.
Configuration for linux-netem:
The linux-netem QoS supports the following key-value pairs:
other_config : latency: optional string, containing an integer
Adds the chosen delay to the packets outgoing to chosen
network interface. The latency value expressed in us.
other_config : limit: optional string, containing an integer
Maximum number of packets the qdisc may hold queued at a
time. The default value is 1000.
other_config : loss: optional string, containing an integer
Adds an independent loss probability to the packets
outgoing from the chosen network interface.
Common Columns:
The overall purpose of these columns is described under Common
Columns at the beginning of this document.
other_config: map of string-string pairs
external_ids: map of string-string pairs
