(Cloud) Services: An Introduction to TOSCA

(Cloud) Services:

An Introduction to TOSCA


(Topology and Orchestration Specification for Cloud Services)

Gerd

Breiter

Frank Leymann

Simon Moser

Thomas
Spatzier

Terminology

2

Caution: Terminology


SOA and Systems Management…



…use the terms “service”, “composition”,
“orchestration”,… differently



…at least with different foci

3

Terminology: Service


“Service” means different things


In SOA: Any kind of (reasonably coarse
-
grained)
application function


Interesting discussion: what is an application? It depends on the
domain…


In Systems Management: Any kind of resource and
appropriate actions required to support business with IT


Interesting discussion: systems management is an application too.
Thus, the SOA notion of service applies too
–

but that might get
confusing at this point in time

4

Terminology: Orchestration


“Orchestration” means different things


In SOA: the aggregation of application functions into
higher level business functions


In Systems Management: the proper sequencing of
individual management tasks to manage complex IT
artifacts


YES: both can be done with the same underlying
technology (BPMN, BPEL,…) but the focus is very
different

5

Terminology: Composition


“Composition” means different things


In SOA/SCA: the aggregation of application functions and
their relations for the purpose of proper deployment


In Systems Management: the “parts tree” of complex IT
artifacts for the purpose of setting up the artifacts
correctly, as well as the processes for ensuring the
appropriate continuous management of the artifacts

6

Conceptual Overview

7

Imagine…


…that you have a nice application that you want to be
able to be hosted in different clouds


Why do you want that?


Because you don’t want to be locked into the platform of
a single cloud provider, or


Because you start in your own private cloud and want to
be able to move it to public cloud or to some community
cloud or to hybrid cloud

8

Cloud

Provider A

Cloud

Provider B

3. Move


(i.e. Provision)

1.
Provision

& Manage

4. Use

5. Manage

Thus, the Scenario is:

Moving Cloud Applications

9

2. Use

What are the Technical Problems?


No interoperable description exists of what your
application is and what it requires


Virtual images do not suffice at all


They are “just” snapshots of the actual state of your application


Another provider might not have a clue how to install,
deploy, run & manage your application


Deep detailed skills about the application and its
underlying stack is needed that “arbitrary” providers
typically don’t have

10

What Is “(Cloud) Service Template” All About?

A new language (“metamodel”) to specify


the building blocks of your application


the management functions these

building blocks offer to be managed



the relations between these building blocks



Collection of node types and relationship types

(for reuse purposes)



the procedures to follow in order to manage your
application as a whole

11

Node

Types

Rel.ship

Types

Plans

Topology

(Template)

(Cloud) Service Template

Group

Template

Graphical Representation

12

Properties

Interfaces

Node

Template

Topology Template

type for

Node Type

Relationship
Template

Service Template

Node Types

Plans

type for

Properties

Relationship Type

Relationship Types

Group

Template

…and More Colorful…

13

Topology

Plans

…and With Angular Brackets…

14

<
ServiceTemplate

…
>





<Extensions/>?





<Import />*




<Types/>?




(




<
TopologyTemplate
/>



|



<
TopologyTemplateReference
/>


)?




<
NodeTypes
/>?





<
RelationshipTypes
/>?



<Plans/>?



</
ServiceTemplate
>

Example: High Level View

15

WebSphere

Cell

DB2 Server

WebSphere

Process

Server

BPEL Files

EJBs

WSDL Files

uses

implemented

by

deployedOn

requires

requires

deployedOn

deployedOn

…and this is
a bit more
clomplex
…

Node Template

Relationship Template

Example:

WebSphere

Cell Refined

16

WebSphere

Cell

IHS

Node

WAS ND

DeployMgr

Node

WAS ND

Managed

Node

Application

Server
Instance

Cluster

DB2 Server

DB2
Database
Instance

"cluster"

"database"

1..*

1..*

exists

Properties, e.g.:

ports
,
servername
,
weight

Properties, e.g.:

WAS
install

location
, Profile
name
,
Node

name

WebSphere

Cell

DB2 Server

Example: Overall Topology Template

17

WebSphere

Cell

IHS

Node

WAS ND

DeployMgr

Node

WAS ND

Managed

Node

Application

Server Instance

Cluster

DB2 Server

DB2 Database
Instance

1..*

1..*

WebSphere

Process

Server

BPEL Files

EJBs

WSDL Files

Example: Amazon

18

WebSphere

Cell

DB2 Server

WebSphere

Process

Server

BPEL Files

EJBs

WSDL Files

uses

implemented

by

deployedOn

requires

requires

deployedOn

deployedOn

Amazon

…Which is the “Interoperable Service Templates” Scenario
(see later)

19

WebSphere

Cell

DB2 Server

WebSphere

Process

Server

BPEL Files

EJBs

WSDL Files

Amazon

Example: Amazon
–

Refined Scenario

20

WebSphere

Cell

DB2 Server

(WAS Data)

WebSphere

Process

Server

BPEL Files

EJBs

WSDL Files

uses

Implemented by

deployedOn

requires

requires

Amazon

DB2 Server

(
Application
Data
)

requires

WebSphere

Cell

deployedOn

On
Premise

Example: Amazon
–

Refined Scenario

(Details)

21

WebSphere

Cell

DB2 Server

(WAS Data)

WebSphere

Process

Server

BPEL Files

EJBs

WSDL Files

uses

Implemented by

deployedOn

requires

requires

Amazon

DB2 Server

(
Applicatio
nData
)

requires

WebSphere

Cell

deployedOn

On
Premise


The Web Services required by the
BPEL processes are hosted on
premise


The EJBs (e.g.) implementing the
Web Services are deployed on
WebSphere hosted on premise


The application data of the WS/EJBs
are stored in DB2 on premise


This ensures compliance with data
privacy/confidentiality rules


Process Server etc is installed
and managed at Amazon’s EC2


The corresponding middleware
is provided as AMIs


The process models are
deployed on Process Server


Process Server maintains state
data in DB2 also running in EC2

Example: Reusing Existing Services

22


Only the processes and
required middleware is
managed on a “known”
cloud


The Web Services needed
by the BPEL processes are
reused “wherever” they are


The existing Web Services
are bound to the BPEL
process by the established
mechanisms


Specifying binding details
can be part of the build plan
of the application’s Service
Template (.ste)

WebSphere

Cell

DB2 Server

WebSphere

Process

Server

BPEL Files

WSDL Files

uses

deployedOn

requires

requires

deployedOn

WS
1

WS
2

WS
n

…

„somewhere
1
“

„somewhere
2
“

„
somewhere
n
“

bound to

Example: SAP

23

Netweaver

Oracle

SAP
Workflow

BPEL Files

EJB

WSDL Files

uses

implemented

by

deployedOn

requires

requires

deployedOn

deployedOn

SAP

Example: Microsoft

24

.Net

SQL Server

BizTalk

BPEL Files

.Net

Assemblies

WSDL Files

uses

implemented

by

deployedOn

requires

requires

deployedOn

deployedOn

Azure

Example: Different
Hosters

of a Particular Application

25

Netweaver

Oracle

SAP
Workflow

BPEL Files

EJB

WSDL Files

uses

implemented

by

deployedOn

requires

requires

deployedOn

deployedOn

IBM

AT&T

T
-
Systems

...

…Which is the “Market for Cloud Applications” Scenario
(see later)

26

Netweaver

Oracle

SAP
Workflow

BPEL Files

EJB

WSDL Files

uses

implemented

by

deployedOn

requires

requires

deployedOn

deployedOn

IBM

AT&T

T
-
Systems

...

Sample:

Websphere

Management Plans

27

Provision
Dmgr

Enable

Admin
Security

Start
Dmgr

Create
Cluster

Provision
Managed

Node


Federate

Node


Deploy

Mon. Agent


Create
Cluster
Members

Provision
IHS
Node

Deploy

Mon. Agent
(IHS)

Start IHS

Configure

Webserver

Start
Cluster

Deploy

Monitoring

Agent
(
Dmgr
)

Provision
Managed

Node


Federate

Node


Deploy

Mon. Agent


Create
Cluster
Members

Start
Cluster

Unfederate

Node


Reconfigure

Webserver

Remove

Mon. Agent


Deprovision

Managed

Node


Initial

Provisioning

Add Nodes

Remove Nodes

How Plans and Nodes Fit Together


Task of a plan refers to interface of a topology node





Topology node specifies all interfaces offered to manage
it


Interface is bound to a concrete implementation





Implementation already available at providers side, or


Implementation is copied from somewhere, or


A standardized Cloud Interface (Iaas, PaaS, SaaS) is used,
or ...


28

WebSphere

Cell

…

Create
Cluster

…

…

Script

-

-

-

-

-

-

-

-

-

-

-

-

-

-


-

-

-

-

-

-

-

-

-

-

-

-

-

-


-

-

-

-

-

-

-

-

-

-

-

-

-

-


-

-

-

-

-

-

-

-

-

-

-

-

-

-


-

-

-

-

-

-

-

-

-

-

-

-

-

-

…refers to…

…bound to…

A Caveat!


The “(Cloud) Service Template” spec is
not

(!) about
standardizing topologies and plans for a series of
concrete products


The “(Cloud) Service Template” spec
is

(!) about
standardizing the
language

that can be used to
precisely describe topologies and plans for concrete
products


Various products (i.e. their topologies and plans) can
be standardized base on that at a later time


By various domain experts, vendors,…

29

Baseline


TOSCA is modular and composable



It does not reinvent the wheel, i.e. it uses existing
standards wherever possible


E.g. WSDL, BPMN, OVF,…

30

Motivation

31

Cloud

Provider A

Cloud

Provider B

4. Move

Service Template

Service Instance

Service Instance

Service Template

1. Build

2. Use

3.
Want

Use

5. Build

6. Use

Scenario 1:

Mobility of Cloud Applications

32

Important Note


TOSCA deals with interoperability of Service
Template
s

here


I.e. portability of the ingredients of an IT Service
(especially the code artifacts) is
not

addressed by
TOSCA


Similarly, mobility of data used by a corresponding
service instance is
not

in the scope of TOSCA

33

Service

Catalog

1. Create

2. Publish

3. Browse

and Select

4. Provision

5. Use

Service Template

Service Instance

Scenario 2:

Creating a Market For Cloud Applications

34

Cloud

Provider A

Realized By

Implemented As

Cloud

Provider C

Cloud

Provider B

Scenario 3:

Interoperable Service Compositions

35

Scenario 4:

Using OVF Packages

36

Note
: only subtree of service

definition relates to OVF, other

subtrees/nodes can point to

shared resources (e.g. DB2,…)

<ovf:Envelope ... >


<ovf:VirtualSystemCollection...>



<ovf:VirtualSystem ... >


...


<ovf:ProductSection ... >


...


</ovf:ProductSection ... >


...


</ovf:VirtualSystem>



<ovf:VirtualSystem ... >


...


</ovf:VirtualSystem>



...



</ovf:VirtualSystemCollection>

</ovf:Envelope>

Refined View

37

How ...

----

----

----

----

----

----

----

----

----

OVF

OVF

OVF

With ...

Scripts

Workflows

EAR (EJBs,…)

BPEL

The images of the
middleware (DB2,
Websphere,…)
required to run the
application

The business logic of
the application, e.g.
EJBs, JSPs, JPEG,…

The business
processes of the
application (BPEL,
BPMN, Human
Tasks,…)

(Existing) scripts
used by task of plans
to manage the cloud
application

(Existing) workflows used by
subprocess
-
tasks of plans

Service

Cloud Management & Orchestration

38

SaaS

Server

Server

Storage

AppSrv

DB

Application

PaaS

IaaS is maturing. Evolution of standards
like OVF or defacto standards like EC2
or S3 enable growth of ecosystems.

PaaS offerings exist (e.g. MicroSoft
Azure), but are restricted solely to the
PaaS layer.

SaaS offerings exist (e.g Google Apps),
but as standalone offerings restricted to
the SaaS layer.

Interfaces between PaaS and IaaS
starting to evolve.

Components in a
composite

service

can

come

from

one

Cloud
,
multiple
Clouds
,
or

can

be

non
-
Cloud

resources

(e.g.
existing

company

LDAP
or

private DBs).

Management
Scope

Management Functionality

Deploy,
Decommission

Start,
Stop,
Resize

Management Plans
covering
the
complete service life
cylce
.

IaaS

Cloud

Management & Orchestration

Service Template: Specification Overview

39

Ingredients of a Service Template

40

Properties

Interfaces

Node

Template

Topology Template

type for

Node Type

Relationship
Template

Service Template

Node Types

Plans

type for

Properties

Relationship Type

Relationship Types

Group

Template

Structure of .ste Document

41

<
ServiceTemplate

id="ID" name="string"

targetNamespace
="
anyURI
">




<Extensions/>?




<Import />*




<Types/>?




(


<
TopologyTemplate
/>

|


<
TopologyTemplateReference
/>

)?




<
NodeTypes
/>?




<
RelationshipTypes
/>?



<Plans/>?



</
ServiceTemplate
>

Topology Template

Node Types

Relationship Types

Plans

Node Types: Overall Structure

42

<
NodeTypes
>?




<
NodeType

id="ID" name="string">+




<
NodeTypeProperties

element="
Qname
"?

type="
QName
"?/>?




<
DerivedFrom

nodeTypeRef
="
QName
"/>?



<
InstanceStates
/>?




<Interfaces/>?




<
DeploymentArtifacts
/>?




<Policies/>?




</
NodeType
>



</
NodeTypes
>

Properties

Interface

Node Type

Node Types

Interfaces of Node Types

43

<Interfaces>?



<Interface>+



(


<
WSDL

portType
="
QName
“ operation="
NCName
">+


|


<
REST

method="
GET

| PUT | POST | DELETE"


requestURI
="
anyURI
"


requestPayload
="
QName
"?


responsePayload
="
QName
"?>+


|


<
Operation

name="
NCame
">+



<
InputParameters
>?



<
InputParamter

name="string"


type="string"


required="
yes
|no
">+



</
InputParameters
>



<
OutputParameters
>?



<
OutputParamter

name="string"


type="string">+



</
OutputParameters
>


<
Implementations
>


<Implementation
implementationID
="
anyURI
"?


language="
anyURI
"?>+


(


<
ImplementationProper
>?


code


</
ImplementationProper
>


|


<
ImplementationReference

ref="
anyURI
"/>?



)


<Implementation>



</Implementations>


</Operation>


)


</Interface>


</Interfaces>

Interfaces

Deployment
Artfacts

of Node Types

44


<
DeploymentArtifacts
>?


<
DeploymentArtifact



name="string"


type="
anyURI
">+


artifact specific content


</
DeploymentArtifact
>

</
DeploymentArtifacts
>


Policies of Node Types

45




<Policies>?


<Policy


name="string"


type="
anyURI
">+


policy specific content


</Policy>


</Policies>


Example: Node Types

<
ServiceTemplate

name="
myService
"


targetNamespace
="http://www.ibm.com/sample">




<
NodeTypes
>




<
NodeType

name="Project">




<documentation
xml:lang
="EN">


A reusable definition of a node type supporting


the creation of new projects.


</documentation>




<
NodeTypeProperties

element="
ProjectProperties
"/>





<
InstanceStates
>


<
InstanceState

state="
www.my.com
/active"/>


<
InstanceState

state="
www.my.com
/
onHalt
"/>


</
InstanceStates
>



...


...

<Interfaces>


<Interface>


<Operation name="
CreateProject
">


<
InputParameters
>


<
InputParamter

name="
ProjectName
"


type="string"/>


<
InputParamter

name="Owner"


type="string"/>


<
InputParamter

name="
AccountID
"


type="string"/>


</
InputParameters
>


<Implementations>


<Implementation>


...


</Implementation>


</Implementations>


</Operation>


</Interface>


</Interfaces>




</
NodeType
>




</
NodeTypes
>



</
ServiceTemplate
>>

Relationship Types

47


<
RelationshipTypes
>




<
RelationshipType

id="ID"


name="string"


semantics="
anyURI
"


cascadingDeletion
="
yes|no
">+




<
RelationshipTypeProperties

element="
QName
"?


type="
QName
"?/>?



<
InstanceStates
>?


<
InstanceState

state="
anyURI
">+


</
InstanceStates
>




</
RelationshipType
>



</
RelationshipTypes
>


Properties

Relationship Type

Relationship Types

Example: Relationship Types

<
RelationshipTypes
>




<
RelationshipType

name="
processDeployedOn
"


semantics="www.my.com/RelSemantics/procDeployedOn"


cascadingDeletion
="yes">




<
RelationshipTypeProperties

element="
ProcessDeployedOnProperties
"/>




<
InstanceStates
>


<
InstanceState

state="
www.my.com
/
successfullyDeployed
"/>


<
InstanceState

state="
www.my.com
/failed"/>


</
InstanceStates
>





</
RelationshipType
>



</
RelationshipTypes
>

<
TopologyTemplate

id="ID"

name="string"?>




(


<
NodeTemplate
/>



|


<
RelationshipTemplate
/>


|


<
GroupTemplate
/>


)+




</
TopologyTemplate
>^

Topology Template

49

Node Template

…type for…

Relationship
Template

…type for…

Group

Template

Topology Template
(cont.)

50

<
TopologyTemplate

id="ID" name="
NCName
">


(



<
NodeTemplate

id="ID" name="string"
nodeType
="
QName
"


minInstances
="
int
"?

maxInstances
="
int|string
"?>+



<
PropertyDefaults
>?


XMLDocument


</
PropertyDefaults
>



<
PropertyConstraints
>?



<
PropertyConstraint

property="string"


constraintType
="
anyURI
">+


constraint
?


</
PropertyConstraint
>



</
PropertyConstraints
>



<Policies/>?


<
EnvironmentConstraints
>?


<
EnvironmentConstraint

constraintType
="
anyURI
">+


constraint type specific content?


</
EnvironmentConstraint
>


</
EnvironmentConstraints
>



<
DeploymentArtifacts
/>?


</
NodeTemplate
>



|



<
RelationshipTemplate
/>



|


<
GroupTemplate
/>


)+


</
TopologyTemplate
>

Node Template

…type for…

Relationship
Template

…type for…

Group

Template

Topology Template (cont.)

51

<
TopologyTemplate

id="ID" name="
NCName
">



(


<
NodeTemplate
/
>



|


<
RelationshipTemplate

id="ID" name="string"


relationshipType
="
QName
">+



<
SourceNodeElement

id="IDREF"/>



( <
TargetNodeElement

id="IDREF"/>


|


<
TargetNodeTemplate
Reference



name="
QName
"/>


)



<
PropertyDefaults
/>?


<
RelationshipConstraints
>?



<
RelationshipConstraint

constraintType
="
anyURI
">+


constraint
?


</
RelationshipConstraint
>



</
RelationshipConstraints
>



</
RelationshipTemplate
>



|


<
GroupTemplate
/>


)+



</
TopologyTemplate
>

Node Template

…type for…

Relationship
Template

…type for…

Group

Template

Topology Template (cont.)

52

<
TopologyTemplate

id="ID" name="
NCName
">



(


<
NodeTemplate
/>



|


<
RelationshipTemplate
/>



|


<
GroupTemplate

id="ID"


name="string"?


minInstances
="
int
"?


maxInstances
="
int|string
"?>




(


<
NodeTemplate

... />


|


<
RelationshipTemplate

... />


|


<
GroupTemplate

... />


)+




<Policies/>


</
GroupTemplate
>


)+



</
TopologyTemplate
>

Node Template

…type for…

Relationship
Template

…type for…

Group

Template

Example: Service Topology Template

<
ServiceTemplate

name="
myService
"


targetNamespace
="http://www.ibm.com/sample"


xmlns:abc
="http://www.ibm.com/sample">




<Import namespace="http://www.ibm.com/sample"


importType
=" http://www.example.org/STE"/>




<
TopologyTemplate

name="
VirtualServerProject
">




<
NodeTemplate

id="
myProject
"


nodeType
="
abc:Project
">


<
PropertyDefaults
>


<
ProjectProperties
>


<Owner>Frank</Owner>


<
ProjectName
>Thomas’ favorite project</
ProjectName
>


</
ProjectProperties
>


</
PropertyDefaults
>


<
NodeTemplate
/>



<
NodeTemplate

id="
myVirtualServer
"


nodeType
="
abc:VirtualServer
"


minInstances
="0"


maxInstances
="unbounded"/>



...


…



<
RelationshipTemplates
>


<
RelationshipTemplate

name="
myRelationship
"


relationshipType
="contains">


<
SourceNodeElement

id="
myProject
"/>


<
TargetNodeElement

id="
myVirtualServer
"/>


</
RelationshipTemplate
>


</
RelationshipTemplates
>




</
TopologyTemplate
>



</
ServiceTemplate
>

53

Plans

54

<Plans>




<Plan id="ID"


name="string"?


planType
="
anyURI
"


languageUsed
="
anyURI
">+




<
PreCondition

expressionLanguage
="
anyURI
">?


condition


</
PreCondition
>




( <
PlanModel
>


actual plan


</
PlanModel
>


|


<
PlanModelReference

reference="
anyURI
"/>


)




</Plan>



</Plans>

Plans

Example: Plans



...



<Plan id="
RemoveApplication
"


planType
=


"http://
www.example.org
/STE/
PlanTypes
/
TerminatioPlan
"


languageUsed
=


"http://
docs.oasis
-
open.org
/
wsbpel
/…/executable">


<
PlanModelReference

reference="
prj:RemoveApp
"/>


</Plan>



</Plans>

<Plans>




<Plan id="
DeployApplication
"


name="Sample Application Build Plan"


planType
=


"http://
www.example.org
/STE/
PlanTypes
/
BuildPlan
"


languageUsed
="http://
www.omg.org
/spec/BPMN/2.0/">




<
PreCondition

expressionLanguage
="
www.my.com
/text">?


Run only if funding is available


</
PreCondition
>




<
PlanModel
>


<process name="
DeployNewApplication
" id="p1">


<task id="t1" name="
CreateAccount
"/>


<task id="t2" name="
AcquireNetworkAddresses
"


isSequential
="false"


loopDataInput
="t2Input.LoopCounter"/>


<
sequenceFlow

id="s1"
targetRef
="t2"
sourceRef
="t1"/>


...


</process>


</
PlanModel
>



...



Scenario

56

Sample
Node

Type:
SuperStorage

<
xs:element

name="
StorageProperties
">


<
xs:complexType
>


<
xs:sequence
>


<
xs:element

name="
TotalStorageAmount
" type="
xs:string
"/>


<
xs:element

name="
IPAddress
" type="
xs:string
"/>



…


</
xs:sequence
>


</
xs:complexType
>


</
xs:element
>

<NodeType name="SuperStorage">



<NodeTypeProperties element="StorageProperties"/>



<Interface>


<Operation name="CreateStorageContainer">


<REST method="POST"


…


<Operation name="AddFile">


<REST method="PUT"


…


…


</Interface>


</NodeType>

Vendor

„
BestStorageVendor
“ Sells ist Devices
with

Corresponding

Node

Template


BestStorageVendor defines Node Template to specify its BestStorageDevice based on former
Node Type


Vendor sets Properties that are known from the outset


TotalStorageAmount is known


IPAddress is set during installation/deployment


Implementation of interface is referenced from Node Template

<NodeTemplate name="BestStorageDevice" nodeType="SuperStorage"
>


<PropertyDefaults>


<TotalStorageAmount>1000TB</TotalStorageAmount>


</PropertyDefaults>



<DeploymentArtifacts>


<DeploymentArtifact name="InterfaceImplementation" type="WARref">


...


</DeploymentArtifact>


</DeploymentArtifacts>



</NodeTemplate>

Customer Deploys New Device

.......

.....

Service Template

Deployment Artifacts

Storage
API.war

…

TOSCA

Container

TOSCA

Database

1

2

3

Storage
API.war

1.
IPAddress
-
Property of Device is set

2.
StorageAPI.war

is deployed

•
IP address of Servlet Container is set

3.
IP
-
Address of Servlet Container becomes HOST header for REST API

Tasks of Plans are Deployed

Best

Storage

Device

…

Create

Storage

…

…

1. refers to…

3. values from…

TOSCA

Database

<NodeTemplate name="BestStorageDevice" nodeType="SuperStorage"
>


<PropertyDefaults>


<TotalStorageAmount>1000TB</TotalStorageAmount>


</PropertyDefaults>


<NodeType name="SuperStorage">





<Interface>


<Operation name="CreateStorageContainer">


<REST method="POST"


…

CreateStorageContainer

Storage
API.war

2. requires data…

4. locates code…

End of Document

61