ONOSMessageHandlingMechanismImprovement

Inango Proposal

AGENDA

› AboutInango

› ONOSpacketlossissuedescription

› Proposedsolution

› Effortestimation

ABOUTINANGO

› Inango passionisindevelopinginnovativesoftwareforadvancedcommunicationssystems

› WeofferbothproductsandservicesspanningabroadrangeoftechnologiesincludingLinuxandopen-source,optimizations,Yocto,RDK-Bandvirtualization

PACKETLOSSISSUEREPRODUCTIONSETUP

› Mininet networkwith“linear,2”topology

› ONOSserverwith“openflow”and“fwd”applications,“ipv6Forwarding”enabled

› AtrafficgeneratorisusedtogenerateICMPv6fromamininet host:• 100,000IPv6echorequestspersecond• Source:hostsIP• Destination:randomIPv6address

REPRODUCTIONCASEBeforetest Duringtest

FC00::1 FC00::2 FC00::1 FC00::2Traffic

generator

REPRODUCTIONTRAFFICFLOW

NDP

LLDP

ISSUEROOTCAUSEANALYSIS

› WhenthepacketcomestoacontrolleritisaddedtothedispatchQueuequeue

› IfthedispatchQueue isfullthenthepacketgoestothedispatchBacklogdeque

› InthiscasedispatchMessage disablesreadingfromachannel

› WecanlooseinformationifthedispatchQueue isfull

CURRENTPACKETHANDLINGSEQUENCE

PROPOSEDSOLUTION

› Reading amessageandmovingittothedispatchQueue isaquick operation

› ProcessingmessagesfromthedispatchQueue isaslow aoperation

›Weshouldaddseveraldispatchqueuesforthedifferentmessagetypes!

SOLUTIONDETAILS

› MajorPoints• Messagesshouldbeclassifiedbeforeweaddthemintoqueues• Weshouldnotstopreadingincomingpacketsfromasocketifoneofqueuesisfull• Ifwegotanewmessagetoafullqueueweshoulddropit:wehavenoabilitytostoreit

› Stabilitytweaks• WeshouldtrytokeepallcontrolmessageswiththehelpofthedispatchBacklogqueue

• SizeofthedispatchBacklog queueshouldbelimited

PERFORMANCERESULTSFORPOCIMPLEMENTATION

› WealreadyimplementedtheproposedalgorithmonONOS1.12

› ThefixisrelevantforONOS2.0aswell

› WithoriginalONOScode,thelinkgoesdownafter40-60secondsof20KPPStraffic

› Withtheproposedalgorithmwedidnotobserveissueswithlinkstabilityunderloadsofupto50KPPSforseveralminutesunderthesameconditions

PROPOSEDSOLUTION—READING

› Whenthepacketcomes,moveallthemanagementpacketsfromthedispatchBacklog tothedefaultQueue

› Trytoclassifyanincomingpacket.Ifthepacketisclassifiedsuccessfully,addittoaspecifictargetqueue.Ifthetargetqueueisfull,dropthepacket.

› IfthepacketwasnotclassifiedthentrytoaddittothedefaultQueue.IfthedefaultQueue isfullthenthe“PACKET_IN”packetsshouldbedropped.Thenon“PACKET_IN”packetsshouldbeeitheraddedtothedispatchBacklog ordropped.

NEWREADING SEQUENCE

PROPOSEDSOLUTION—PROCESSING

› Oneofpossiblesolutionsisaround-robinalgorithm:• TakeanumberofOFmessagesfrom1-stqueue• Processthem• Dothesamefortherestofthequeues,onebyone• Gobacktothefirstqueueandrepeatthestepsuntilqueuesareempty

NEWPROCESSING SEQUENCE

PROPOSEDCONFIGURATION

› 7priorityqueues,onedefaultQueue andonedispatchBacklog

› Sizeandchunksizecanbeconfiguredseparatelyforeachqueue

› ClassifierscanbeconfiguredforeachOFAgent

› LLDPandBDDPpacketsaremappedtothefirstqueue

› Firstqueuehavesize1000,thedefaultQueue – 5000,otherqueues– 1

› Sizeofchunkofmessagesforeachqueueis100

SUBMITTINGCODE

› ForONOS1.12wemodified11sourcefiles,created19additionalsourcefiles,andchanged12filesthatdescribesbuildsanddependencies

› WeexpectsimilarchangesforONOS2.0

THANKYOU!

ByNikolayMerinov,SWArchitectInango SystemsLtd.inango.comos@inango-systems.com