Supporting Cloud Service Operation

Management for Elasticity

Georgiana Copil, Hong Linh Truong, Schahram Dustdar

Distributed Systems Group

TU Wien

23 November 2015 2

Overview

Motivation

Approach

Use Case

Conclusions

23 November 2015 3

Motivation

Elasticity

Cloud

SU1 SU2

SU

3SU4SU5

SU6SU7

Complex Service A.Company X.

Develops,

Tests,

Deploys,

Manages,

Operates

1. Training employees for operating the service in the cloud

2. Constantly analyze the service at runtime, decide on needed resources, configurations

Deployed

Elasticity

Controller

3. Change in employees responsibilities

Intervene in strategic decisions:

e.g., Does it makes sense to increase the cost?

(actions like negotiation with cloud providers)

Be aware of configuration changes that may happen

automatically

23 November 2015 4

Approach

Supervisory control Level of Automation (LOA)

Model the roles involved and interactions

Define interaction protocols between elasticity controller

and roles

eOMP – elasticity Operations Management Platform

23 November 2015 5

Background

rSYBL controller

SYBL

– Language for elasticity requirements specification

– Requirements can be specified at multiple levels of abstraction

• Programming/code region

• Service Unit

• Service Topology

• Service

#SYBL.CloudServiceLevel

Cons1: CONSTRAINT responseTime < 10 ms WHEN

nbOfUsers > 10000

Str1: STRATEGY CASE fulfilled(Cons1) OR fulfilled(Cons2):

minimize(cost)

#SYBL.ServiceUnitLevel

Str2: STRATEGY CASE ioCost < 3 Euro : maximize(

dataFreshness )

#SYBL.CodeRegionLevel

Cons2: CONSTRAINT dataAccuracy>90% AND cost<4 Euro[Georgiana Copil, Daniel Moldovan, Hong-Linh Truong, Schahram Dustdar, "SYBL: an Extensible Language for Controlling

Elasticity in Cloud Applications", 13th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing (CCGrid),

May 14-16, 2013, Delft, Netherlands]

[Georgiana Copil, Daniel Moldovan, Hong-Linh Truong, Schahram Dustdar, “Multi-Level Elasticity Control of Cloud Services",

the 11th International Conference on Service Oriented Computing. Berlin, Germany, 2-5 December, 2013]

23 November 2015 6

Elasticity requirements language

extension

Notification description

Notification directive example– No1:NOTIFY OperationsManager WHEN responseTime > 1.2 s :

notify(WARNING, "Response time exceeds 1.2 s")

23 November 2015 7

Approach

Supervisory control Level of Automation (LOA)

Model the roles involved and interactions

Define interaction protocols between elasticity controller

and roles

eOMP – elasticity Operations Management Platform

23 November 2015 8

Core Entities for Operations Management

Role

Responsibility

Authority

Cost

Quality

Resources

Error

Analytics

0

10

System

Administrator

System

Analyst

Interaction

Initiator

Receiver

Message

Dialog

Header

BodyType

PriorityContent

Suggested

MeasureCause

23 November 2015 9

Approach

Supervisory control Level of Automation (LOA)

Model the roles involved and interactions

Define interaction between elasticity controller and roles

eOMP – elasticity Operations Management Platform

23 November 2015 10

Interactions flow

Notifying roles about changes

From roles to actions

Message 1

Message 2

Message 3

<<receives>>

Responsibilities

Elasticity

Operations

Actions

<<hasAssociated>>

<<performs>> <<notifies>>

<<delegates>>

23 November 2015 11

Interaction example – Bootstrapping

23 November 2015 12

Approach

Supervisory control Level of Automation (LOA)

Model the roles involved and interactions

Define interaction protocols between elasticity controller

and roles

eOMP – elasticity Operations Management Platform

23 November 2015 13

eOMP Design

Design

Interactions

– Role as initiator:

• Bootstrapping dialogs: initiating the controller

• Request for Change (RFC): requesting for changes in elastic

service desired behavior

– Elasticity controller as initiator:

• Notifying on conflicts, incidents or simply enforced actions

23 November 2015 14

eOMP Design

Design

Interaction Aggregation

– Interaction management component routing:

• Nature of the interactions– responsibilities, authority

• Number of interactions

23 November 2015 15

eOMP Use Case - Setting

Setting

– We assume the DSG service provider, which wants to provide

the M2MDaaS Service

– DSG organization members (employees): Schahram Dustdar,

Hong-Linh Truong, Georgiana Copil

– Roles: System Administrator, Financial Manager, Procurement

Analyst, Service Manager, Configuration Librarian, Incident

Analyst

– We captured monitoring information for the M2MDaas, and

inserted incidents in the monitored data, for producing

interactions – using rSYBL feature we replay this data

23 November 2015 16

eOMP use case – interaction participants

Service provider roles and employees

23 November 2015 17

eOMP Use Case – Solving conflicting

requirements [1]

Requirements conflict identified during runtime

23 November 2015 18

eOMP Use Case – Solving conflicting

requirements [2]

Dialog for solving conflictsInitial Interaction

Problem fix

rSYBL Elasticity Controller View

23 November 2015 19

eOMP Use Case – Service health

incidents

Unhealthy service part dialog

Initial Interaction

Delegate to role

Fix: pause control, manually fix, and replace

service descriptions for the controller

23 November 2015 20

eOMP Use Case – Dealing with roles

authorities Interaction number depends on the role’s

authority and its responsibilities

• Service Manager(highest role) has no

interactions

• System Administrator(lowest authority

role, also many responsibilities

associated) has most interactions

The number of interactions depends on:

• The workload and incidents which

appear

• Role’s responsibilities and their rapidity

in solving issues

23 November 2015 21

Conclusion

So far we have:

– proposed including the service provider roles in the service

elasticity control loop as first class entity

– introduced new interaction protocols facilitating collaboration

between roles & elasticity controllers

– Prototype available at http://tuwiendsg.github.io/rSYBL/eOMP

Future work

– Multi-organizational interactions for cloud service operations

management

23 November 2015 22

Thanks for your attention!

Georgiana Copil

e.copil@dsg.tuwien.ac.athttp://www.infosys.tuwien.ac.at/staff/ecopil/

Distributed Systems GroupTU Wien

Austria