A Global Name Service for a Highly Mobile Internetwork

A Global Name Service for a Highly Mobile Internetwork

Abhigyan Sharma, Xiaozheng Tie, Hardeep Uppal, Arun Venkataramani, David Westbrook, Aditya Yadav

School of Computer ScienceUniversity of Massachusetts Amherst

1

UNIVERSITY OF MASSACHUSETTS AMHERST • School of Computer Science

Mobile arrived, but Internet unmoved

Unidirectional communication initiation

Redundant app-specific mobility support

2

Cleaner separation of location and identity commonly advocated wisdom

?

Alice’s phoneNotification systemsVoIP/messagingCloud storage

Bob

Alice

Ungraceful disruptions

UNIVERSITY OF MASSACHUSETTS AMHERST • School of Computer Science 3

But DNS does separate identity / location

Challenge: scaling to handle update cost of frequent mobility while returning up-to-date values• Example: 10B devices, 100 addresses/day ≈ 1M updates/sec • DNS update propagation can takes hours or days today!

Domain names IP addresses

+ connection migration techniques


Scalable global name service (GNS)

Goal: A massively scalable, logically centralized GNS to enable secure, name-based communication with

flexible endpoint principals with arbitrary (fixed) names despite high mobility.

Global name service (GNS)interface deviceservice content group of names

f0:56:81:c1:c0:ebnode1.cs.umass.edudropbox.comnetflix.com/<object>devices in [lat,long,radius]


Outline

Poor intrinsic support for mobility today Case for a next-generation GNS Auspice GNS design Implementation and evaluation Related work, open issues, summary


GNS critical to handle mobility

Global name service

Alic

eIP1

IP2

IP3

Bob’s address?

IP4

IP5

Bob

IP6

IP7

Alic

e’s a

ddre

ss?Pre-lookup mobility

Connect-time mobility

Individual mobility

Simultaneous mobility

Pre-lookup mobility

GNS critical or can significantly benefit mobility handling in any network architecture


DNS limitations

DNS

cacheLoad α 1/TTLLatency α 1/TTL

MobilityMobility

Passive caching

Static placement

Hierarchical names

Authoritative name-server ns.xyz.net

node1.xyz.net

.

com edu net

yahoo cnn umass

cs ece

Federation

DN

SSEC key chain

Single root of trust

“JohnSmith2178@Amherst”“Living room chandelier”“Taxis near Times Square”


Outline



GNS: Decoupling certification and resolution

Nam

e: “A

lice’

s p

hone

”

TLD name services

Auth. name services

Root name service (ICANN, US. Dept. of Commerce)

Certificate search services

GU

ID=X, G

NS=Auspice

Domain name system Global name system

getA

ddre

ss(X

) [IP

1, I

P 2,…

]

3

3

4

41

0Local name services

1

Local name services

2Name certification services

Managed DNS services

Auspice-like global name services


Reso

urce

cos

t

Name lookup latency

Consistent hashing with (static) k-replication

Auspice

Resource limit

Active replication cost-benefit tradeoff

Replicate-at-all-locations

Update cost for name i α (#replicasi) x (update_ratei)

Lookup latency for name i ?


Demand-aware active replication

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NS1

NS2

NS3

NS4

NS5

NS6

NS7

NS8NS10

NS9

NS11

i

i

i

#replicas of name i α (read_ratei) / (update_ratei)

ii

ij

j

j

Geolocality-aware Load-awarejjj


Placement reconfiguration engine

NS1

NS2

NS3

NS4

NS5

NS6

NS7

NS8NS10

NS9

NS11

i i

ij

j

j

NS3

NS7

NS2

NS4

NS9

NS1

Paxos

NS5NS8

NS10

NS11

i

i

i

i = replica controller for name ii = name record for name iname i

Demandgeo-distribution

ii

Consistent hashing based placement control plane

Planned demand-aware placement for data plane


Outline



Implementation Geo-distributed key-value store

Name certification service

msocket user-level socket library with Auspice integration

GUID: { {IPs: [123.45.67.89, 98.76.54.321]},{geoloc:[lat, long]},{TE_prefs: [“prefer WiFi”,…]},{ACL: {whitelist: […]}},…}

Human-readable name: [email protected]:phoneGUID: 21EC2020-3AEA-4069-A2DD-08002B30309D

MSocket socket = new MSocket([email protected]:phone);MServerSocket socket = new MServerSocket(8080);

mailto:[email protected]





Placement schemes comparison

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Auspice gives close to best throughput and up to 9x lower latency than DHT+Popularity

Testbed: 16 server cluster emulating with 80 NS an 80 local NSWorkload: 90% mobile names (geolocality 0.75), 10% service names


Managed DNS comparison

One-third replication cost, similar latency

60% less latency, similar cost

Auspice reduces cost/latency over today’s managed DNS

Ultra DNS (16 replicas) vs. Auspice 5/10/15 replicas out of 80 locations


Classical name services [Grapevine/ClearingHouse] used static replication• Context-based names like Lampson’s “descriptive names”

DHT-based DNS designs [CoDoNS] ensure load balance, oblivious to demand geo-locality• Locality-aware DHTs [SkipNet] (statically) place content close

to origin, not near regions of its (dynamic) demand Modern KV data stores support static geo-replication

[Cassandra] or manually-configured policy [Spanner]

Related work

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“the XEROX system [Grapevine] was then … the most sophisticated name service in existence, but it was not clear that its heavy use of replication, light use of caching ... were appropriate”

msocket.bind([lat, long, radius])

msocket.send(msg)msgmsgmsgmsgmsg


Auspice GNS summaryEnables secure, name-based communication • arbitrary name/location representation• flexible endpoint principals• handles all types of mobility

Key differences from DNS for today’s Internet• federation decoupling certification and resolution• active replication• demand-aware placement

Get your GUID at: http://gns.name

A Global Name Service for a Highly Mobile Internetwork

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