Table of Contents
Support for QoS Alert¶
https://git.opendaylight.org/gerrit/#/q/topic:qos-alert
This feature adds support to monitor the per port packet drop counts when QoS rate limit rule is applied.
Problem description¶
If QoS bandwidth policy is applied on a neutron port, all packets exceeding the rate limit are dropped by the switch. This spec proposes a new service to monitor the packet drop ratio and log the alert message if packet drop ratio is greater than the configured threshold value.
Proposed change¶
Proposed new service will use the RPC
/operations/opendaylight-direct-statistics:get-node-connector-statistics
provided by
openflowplugin to retrieve port statistics directly from switch by polling at regular interval.
Polling interval is configurable with default value of 2 minutes.
Port packet drop ratio is calculated using delta of two port statistics counters
rx_dropped
and rx_received
between the sample interval.
packet drop ratio = 100 * (rx_dropped / (rx_received + rx_dropped ))
An message is logged if packet drop ratio is greater than the configured threshold value.
Existing logging framework log4j
shall be used to log the alert messages in the log file.
A new appender qosalertmsg
shall be added in org.ops4j.pax.logging.cfg
to define the
logging properties.
Log file format¶
2017-01-17 01:17:49,550 Packet drop threshold hit for qos policy qospolicy1 with qos-id qos-2dbf02f6-dcd1-4c13-90ee-6f727e21fe8d for port port-3afde68d-1103-4b8a-a38d-9cae631f7d67 on network network-563f9610-dd91-4524-ae23-8ec3c32f328e rx_received 4831 rx_dropped 4969
2017-01-17 01:17:49,550 Packet drop threshold hit for qos policy qospolicy2 with qos-id qos-cb7e5f67-2552-4d49-b534-0ce90ebc8d97 for port port-09d3a437-f4a4-43eb-8655-85df8bbe4793 on network network-389532a1-2b48-4ba9-9bcd-c1705d9e28f9 rx_received 3021 rx_dropped 4768
2017-01-17 01:19:49,339 Packet drop threshold hit for qos policy qospolicy1 with qos-id qos-2dbf02f6-dcd1-4c13-90ee-6f727e21fe8d for port port-3afde68d-1103-4b8a-a38d-9cae631f7d67 on network network-563f9610-dd91-4524-ae23-8ec3c32f328e rx_received 3837 rx_dropped 3961
2017-01-17 01:19:49,339 Packet drop threshold hit for qos policy qospolicy2 with qos-id qos-cb7e5f67-2552-4d49-b534-0ce90ebc8d97 for port port-09d3a437-f4a4-43eb-8655-85df8bbe4793 on network network-389532a1-2b48-4ba9-9bcd-c1705d9e28f9 rx_received 2424 rx_dropped 2766
Pipeline changes¶
None.
Yang changes¶
A new yang file shall be created for qos-alert configuration as specified below:
module qosalert-config {
yang-version 1;
namespace "urn:opendaylight:params:xml:ns:yang:netvirt:qosalert:config";
prefix "qosalert";
revision "2017-01-03" {
description "Initial revision of qosalert model";
}
description "This YANG module defines QoS alert configuration.";
container qosalert-config {
config true;
leaf qos-alert-enabled {
description "QoS alert enable-disable config knob";
type boolean;
default false;
}
leaf qos-drop-packet-threshold {
description "QoS Packet drop threshold config. Specified as % of rx packets";
type uint8 {
range "1..100";
}
default 5;
}
leaf qos-alert-poll-interval {
description "Polling interval in minutes";
type uint16 {
range "1..3600";
}
default 2;
}
}
}
Configuration impact¶
Following new parameters shall be made available as configuration. Initial or default configuration
is specified in netvirt-qosservice-config.xml
Sl No. |
configuration |
Description |
---|---|---|
|
configuration parameter to enable/disable the alerts |
|
|
Drop percentage threshold configuration. |
|
|
Polling interval in minutes |
Logging properties like log file name, location, size and maximum number of backup files are
configured in file org.ops4j.pax.logging.cfg
Clustering considerations¶
In cluster setup, only one instance of qosalert service shall poll for port statistics. Entity owner service (EOS) shall be used to determine the owner of service.
Security considerations¶
None.
Scale and Performance Impact¶
QoS Alert Service minimizes scale and performance impact by following:
Proposed service uses the direct-statistics RPC instead of OpenflowPlugin statistics-manager. This is lightweight because only node-connector statistics are queried instead of all statistics.
Polling frequency is quite slow. Default polling interval is two minutes and minimum allowed value is 1 minute.
Targeted Release¶
Carbon.
Alternatives¶
N.A.
Usage¶
Features to Install¶
This feature can be used by installing odl-netvirt-openstack
.
This feature doesn’t add any new karaf feature.
REST API¶
Put Qos Alert Config¶
Following API puts Qos Alert Config.
Method: POST
URI: /config/qosalert-config:qosalert-config
Parameters:
Parameter |
Type |
Value range |
Comments |
---|---|---|---|
|
Boolean |
true/false |
Optional (default false) |
|
Uint16 |
1..100 |
Optional (default 5) |
|
Uint16 |
1..65535 |
Optional time interval in minute(s) (default 2) |
Example: .. code-block:: json
- {
“input”: {
“qos-alert-enabled”: true,
“qos-drop-packet-threshold”: 35,
“qos-alert-poll-interval”: 5
}
}
Implementation¶
Assignee(s)¶
- Primary assignee:
Arun Sharma (arun.e.sharma@ericsson.com)
- Other contributors:
Ravi Sundareswaran (ravi.sundareswaran@ericsson.com)
Mukta Rani (mukta.rani@tcs.com)
Work Items¶
Trello Link <https://trello.com/c/780v28Yw/148-netvirt-qos-alert>
Adding new yang file and listener.
Adding new
log4j appender
in odlparentorg.ops4j.pax.logging.cfg
file.Retrieval of port statistics data using the openflowplugin RPC.
Logging alert message into the log file.
UT and CSIT
Dependencies¶
This doesn’t add any new dependencies.
Testing¶
Capture details of testing that will need to be added.
Unit Tests¶
Standard UTs will be added.
Integration Tests¶
N.A.
CSIT¶
Following new CSIT tests shall be added
Verify that alerts are generated if drop packets percentage is more than the configured threshold value.
Verify that alerts are not generated if drop packets percentage is less than threshold value.
Verify that alerts are not generated when
qos-alert-enabled
if false irrespective of drop packet percentage.
Documentation Impact¶
This will require changes to User Guide.
User Guide will need to add information on how qosalert service can be used.