[PDF] - Decentralised Diffusion-based Quota Management Rdiger Kapitza, Meik PDF Document

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1 Rüdiger Kapitza, Meik Felser, Hans P. Reiser, Franz J. Hauck AspectIX Research Group University Erlangen-Nuremberg

Decentralised Diffusion-based Quota Management

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Decentralised Diffusion-based Quota Management

Motivation

Grid infrastructures provide resources Resources are shared among multiple parties Resource access has to be restricted Otherwise a user could allocate all resources

Accident
Attack
Unawareness

Solution: Quotas

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Decentralised Diffusion-based Quota Management

Motivation

Existing implementation of quota-based approaches

1. Quota manager issues fractions of quota to the clients
2. Client can acquire resources up to the quota

Central quota manager is the bottleneck

Large-scale grids
Frequent quota allocations
Single point of failure

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Decentralised Diffusion-based Quota Management

Motivation

decentralised quota management system No central quota service

Scalability

Distributed quota information

Fault-tolerance

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Decentralised Diffusion-based Quota Management

Outline

Motivation Diffusive Balancing

Load Balancing
Quota Balancing
Basic Protocol

Extension for Fault-Tolerance Handling of Non-Refundable Quotas Conclusion and Ongoing Work

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Decentralised Diffusion-based Quota Management

Diffusive Load Balancing

Load balancing for distributed multiprocessor systems (Cybenko, 1998) Nodes are organised in small overlapping groups Load information is exchanged If there is an imbalance, load is migrated

A , B represent nodes
wA , wB denote the current load of nodes A and B
If wA < wB then move load (wA - wB ) / 2 from B to A

and vice versa if wA > wB

A B

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Decentralised Diffusion-based Quota Management

Diffusive Quota Balancing: Basic Idea

Quota management:

Do NOT balance load
Balance the free quota information

Quota information is distributed

Fast resource allocation Resource demand may be fulfilled locally

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Decentralised Diffusion-based Quota Management

Node B

Diffusive Quota Balancing: Basic Idea

Free quota is distributed and balanced among all nodes

Initial distribution of free quota

Node A

free quota

60

Node C

60

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Decentralised Diffusion-based Quota Management

Diffusive Quota Balancing: Basic Idea

Free quota is distributed and balanced among all nodes

Application has been started
Resource demand was fulfilled immediately

Node A Node B Node C

used

60 60 30

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Decentralised Diffusion-based Quota Management

Diffusive Quota Balancing: Basic Idea

Free quota is distributed and balanced among all nodes

System reached quota equilibrium again
Free quota is balanced again

Node A Node B Node C

50 50 50

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Decentralised Diffusion-based Quota Management

Basic Quota Balancing Protocol

Quota Manager:

Initial node
Injection point of initial quota
Not a central component

quota manager

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Decentralised Diffusion-based Quota Management

Basic Quota Balancing Protocol

Quota manager Initial set:

Connected to the quota manager
Connected to some other nodes of the initial set
Forming an unstructured network

quota manager initial set

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Decentralised Diffusion-based Quota Management

Basic Quota Balancing Protocol

Quota manager Initial set Additional nodes:

connect to a random subset of the nodes

quota manager initial set new nodes

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Decentralised Diffusion-based Quota Management

Basic Quota Balancing Protocol

Each node stores its local free quota

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Decentralised Diffusion-based Quota Management

Basic Quota Balancing Protocol

Each node stores its local free quota Global quota is injected into the quota manager

300 300 300

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Decentralised Diffusion-based Quota Management

Basic Quota Balancing Protocol

If the local free quota changes

The nodes exchange quota information and
Balance quota differences

150 150 150 150 150

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Decentralised Diffusion-based Quota Management

Basic Quota Balancing Protocol

If the local free quota changes

The nodes exchange quota information and
Balance quota differences

This continues …

75 75 75 75 75 75 75 75 75 75

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Decentralised Diffusion-based Quota Management

Basic Quota Balancing Protocol

If the local free quota changes

The nodes exchange quota information and
Balance quota differences

This continues until the equilibrium is reached

50 50 50 50 50 50 50 50 50 50 50 50

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Decentralised Diffusion-based Quota Management

Basic Quota Balancing Protocol

Resource demands reduce the free local quota

This can result in negative free local quota

The algorithm starts balancing the free quota

10
10

50 50 50 50 50 50 50 50 50 50

demands 60

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Decentralised Diffusion-based Quota Management

Basic Quota Balancing Protocol

The algorithm is balancing the free quota

30 20 20 50 50 50 50 50 50 20 20 50 50

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Decentralised Diffusion-based Quota Management

Basic Quota Balancing Protocol

Eventually …

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Decentralised Diffusion-based Quota Management

Basic Quota Balancing Protocol

Eventually the system is in equilibrium again

40 40 40 40 40 40 40 40 40 40 40 40

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Decentralised Diffusion-based Quota Management

Basic Quota Balancing Protocol

Node failures lead to the loss of quota information

∑: 200 ∑: 150

50 50 50 50 50 50

node failure

50 50 50 50 50 50 50 50 50 50

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Decentralised Diffusion-based Quota Management

Extension for Fault-Tolerance

Spontaneous node failures should be tolerated

Without losing quota information

Solution: link counter

300 300 300

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Decentralised Diffusion-based Quota Management

Extension for Fault-Tolerance

Spontaneous node failures should be tolerated

Without losing quota information

Solution: link counter

Outgoing quota units are added to the link counter
Incoming quota units are subtracted from the link counter
150

+150

150 150 150 150 150

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Decentralised Diffusion-based Quota Management

Extension for Fault-Tolerance

Spontaneous node failures should be tolerated

Without losing quota information

Solution: link counter

Positive values represent outgoing quota units
Negative values represent incoming quota units
150

+75

75

+150

75 75 75 75 150 150 75

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Decentralised Diffusion-based Quota Management

Extension for Fault-Tolerance

Spontaneous node failures should be tolerated

Without losing quota information

Solution: link counter

Positive values represent outgoing quota units
Negative values represent incoming quota units
150

+75

75
38

+38 +150

75 75 113 113 112 112 38

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Decentralised Diffusion-based Quota Management

Extension for Fault-Tolerance

Spontaneous node failures should be tolerated

Without losing quota information

Solution: link counter

Positive values represent outgoing quota units
Negative values represent incoming quota units
169

+75

75
38

+38 +169

94 94 56 56 93 93 57 57

57

+57

19 57

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Decentralised Diffusion-based Quota Management

Extension for Fault-Tolerance

Spontaneous node failures should be tolerated

Without losing quota information

Solution: link counter Node failure

169

+75

75
38

+38 +169

94 94 56 56 93 93 57 57

57

+57

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Decentralised Diffusion-based Quota Management

Extension for Fault-Tolerance

Spontaneous node failures should be tolerated

Without losing quota information

Solution: link counter used for quota reconstruction!

On node failure link counter is added to local quota.
75
38

+38 +169

56 56 93 93 57 57

57

+57

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Decentralised Diffusion-based Quota Management

Extension for Fault-Tolerance

Spontaneous node failures should be tolerated

Without losing quota information

Solution: link counter used for quota reconstruction!

On node failure link counter is added to local quota.
This may result in negative local quota
38

+38

19
19

262 262 57 57

57

+57

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Decentralised Diffusion-based Quota Management

Extension for Fault-Tolerance

Spontaneous node failures should be tolerated

Without losing quota information

Solution: link counter used for quota reconstruction!

On node failure link counter is added to local quota.
This may result in negative local quota
179

+179

122 122 121 121 57 57

57

+57

141

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Decentralised Diffusion-based Quota Management

Failure of the Quota Manager

Quota manager fails

Initial node set does not evaluate link counter
Quota manager is restored via passive replication

System can run without the quota manager

169

+75

75
38

+38 +169

94 94 56 56 93 93 57 57

57

+57

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Decentralised Diffusion-based Quota Management

Failure of the Quota Manager

Quota manager fails

Initial node set does not evaluate link counter
Quota manager is restored via passive replication

System can run without the quota manager

169

+75

75
38

94 94 56 56 57 57

57

+57

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Decentralised Diffusion-based Quota Management

Handling of Non-Refundable Quotas

Non-Refundable Quotas

Quotas for resources such as transfer volume or CPU cycles

100 100 100 100 100 100 100 100

100

+100 +200

200

+100

100

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Decentralised Diffusion-based Quota Management

Handling of Non-Refundable Quotas

Non-Refundable Quotas

Quotas for resources such as transfer volume or CPU cycles
Can be consumed
link counters won’t help in case of node failures

70

30

70

30

100 100 100 100 100 100

100

+100 +200

200

+100

100

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Decentralised Diffusion-based Quota Management

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Handling of Non-Refundable Quotas

Non-Refundable Quotas

Quotas for resources such as transfer volume or CPU cycles
Can be consumed link counters won’t help
Solution: Propagation of consumed quota to quota manager

70 70 100

30

100

30

100 100 100 100

100

+100 +200

200

+70

70

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Decentralised Diffusion-based Quota Management

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Handling of Non-Refundable Quotas

Non-Refundable Quotas

Quotas for resources such as transfer volume or CPU cycles
Can be consumed link counters won’t help
Solution: Propagation of consumed quota to quota manager

70 70 100 100 100 100 100

30

100

30

100

+100 +170 +70

70
170

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Decentralised Diffusion-based Quota Management

Evaluation

Scenario:

1000 nodes
50 units free quota per node

Increasing number of demanding nodes

up to 500 nodes
each node demands 100 units

number of rounds to satisfy demand 140 130 120 110 100 90 80 70 60 50 40 30 20 10 100% 90 80 70 60 50 40 30 20 10 resource demand

connections per node: max 10: max 5:

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Decentralised Diffusion-based Quota Management

Ongoing Work

Integration into the AspectIX Middleware

EDAS - Environment for Decentralized Adaptive Services
www.aspectix.de

Acquiring resource information from applications

Java Management eXtension (JMX)

Communication service platform

JXTA Peer-to-Peer infrastructure
Peer group for each project
Every peer provides a JXTA service implementing the protocol
Communication via JXTA sockets

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Decentralised Diffusion-based Quota Management

Conclusion

Quota management protocol

Distributed quota information
Local knowledge of available quota fraction

Properties

Decentralised
Scalable
Fault-tolerant

Supports

Refundable and
Non-refundable resources

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Decentralised Diffusion-based Quota Management

Thank you

for your attention!

Any Questions?

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Decentralised Diffusion-based Quota Management