1. ProActive Architecture of an Open Middleware for the Grid
Romain Quilici
ObjectWeb Architecture meeting
July 2nd 2003

2. ProActive A Java API + Tools for Parallel, Distributed Computing
A uniform framework: An Active Object pattern
A formal model behind: Prop. Determinism, insensitivity to deploy.
Main features:
Remotely accessible Objects (RMI, JINI, --> UDDI)
Asynchronous Communications with synchro: automatic Futures
Group Communications, Migration (mobile computations)
XML Deployment Descriptors
Interfaced with various protocols: rsh,ssh,LSF,Globus,--> SOAP
Visualization and monitoring: IC2D
In the ObjectWeb Consortium
since April 2002 (LGPL License)

3. Table of Contents ProActive Runtime Active Objects Model
Future Objects and Automatic Continuation
Groups Communication
Active Objects Migration
Abstract Deployment Model
Components Infrastructure
Security

4. ProActive Runtime Transparently created when using ProActive
Only one by JVM -- Singleton pattern
Offer basics services to create or receive Active Objects
Accessible remotely
Partially hidden from users --> Use of Nodes (look like remote)
ProActive Nodes are defined on PART --> possibly N nodes by JVMs
Use of patterns to improve integration
Smart Proxy
Adapter
Factory ….

5. ProActive Runtime Architecture RMI case
Node1
Jvm1
Jvm2
Node1 properties
Singleton
Factory
PART
PART Smart Proxy
Adapter
PART Stub
PART Remote

6. Table of Contents ProActive Runtime Active Objects Model
Future Objects and Automatic Continuation
Groups Communication
Active Objects Migration
Abstract Deployment Model
Components Infrastructure
Security

7. Active Object Model
Active objects : coarse-grained structuring entities (subsystems)
Each active object: - possibly owns many passive objects
- has exactly one thread.
No shared passive objects -- Parameters are passed by deep-copy
Asynchronous Communication between active objects
Future objects and wait-by-necessity.
Full control to serve incoming requests (reification)

8. Creating active objects
Instantiation-based:
A a = (A)ProActive.newActive(«A», params, node);
To get a non-FIFO behavior (Class-based):
class pA extends A implements RunActive { … }
Object-based:
A a = new A (obj, 7);
...
a = (A)ProActive.turnActive (a, node);

9. ProActive: Reuse and seamless
Two key features:
Polymorphism between standard and active objects
Type compatibility for classes (and not only interfaces)
Needed and done for the future objects also
Dynamic mechanism (dynamically achieved if needed)
Wait-by-necessity: inter-object synchronization
Systematic, implicit and transparent futures (“value to come”)
Ease the programming of synchronizations, and the reuse of routines
"A"
"pA" a
p_a
foo (A a) {
a.g (...);
v = a.f (...);
...
v.bar (...); }
O.foo(a) : a.g() and a.f() are « local »
O.foo(p_a): a.g() and a.f()are remote + Async.»

10. Active Object Components
Caller
Stub
Object
Object
Proxy
Body
Components of an Active Object

11. Active Object Architecture RMI case
Jvm1
Jvm2
Caller
Byte code generation with asm
Stub
Object
Object
Proxy
Body
RMI Specific
Body
Smart Proxy
Body Stub
Remote
Body

12. Body Architecture Object Body Request Receiver Reply Sender
Reply Receiver
Body
FuturePool
Service
RequestLine
Object

13. Request to an Active Object
Caller
Body
Request Receiver
Reply Receiver
Reply Sender
Service
Objet 1
1 - Call 5
5 - Sending back the reply 2
2 - Reception of Request 3
3 - Selection of Request 4
4 - Execution

14. Table of Contents ProActive Runtime Active Objects Model
Future Objects and Automatic Continuation
Groups Communication
Active Objects Migration
Abstract Deployment Model
Components Infrastructure
Security

15. Future Objects A res = ActiveObject.foo();
Stub_A
Future
Proxy
res
Caller
The caller receives a Future : it continues its execution
If it tries to access to the value or res, it is blocked in the future
proxy (Wait By Necessity), until this value is available

16. Future Objects Object A res = ActiveObject.foo();
Stub_A
Future
Proxy
Object
res
Caller
When the called object finish the computation of res, the value
is returned to the caller
Future is updated transparently

17. Automatic Continuation
Caller a b

18. Automatic Continuation
A Future can be passed by parameter or by result: chains of
futures will be updated by Automatic Continuation. …
r1=a.foo()
Caller
r1=a.foo() a b

19. Automatic Continuation
A Future can be passed by parameter or by result: chains of
futures will be updated by Automatic Continuation. …
r1=a.foo()
Caller a
Future_r1 b

20. Automatic Continuation
A Future can be passed by parameter or by result: chains of
futures will be updated by Automatic Continuation. …
r1=a.foo()
r2=b.bar(r1)
Caller a
r2=b.bar(r1)
Future_r1 b

21. Automatic Continuation
A Future can be passed by parameter or by result: chains of
futures will be updated by Automatic Continuation. …
r1=a.foo()
r2=b.bar(r1)
Caller a
Future_r1 b
Future_r1
Future_r2

22. Automatic Continuation
A Future can be passed by parameter or by result: chains of
futures will be updated by Automatic Continuation. …
r1=a.foo()
r2=b.bar(r1)
Caller a
UPDATE
Future_r1 b
Future_r1
Future_r2
Value_r1

23. Automatic Continuation
A Future can be passed by parameter or by result: chains of
futures will be updated by Automatic Continuation. …
r1=a.foo()
r2=b.bar(r1)
Caller a
UPDATE
Future_r1 b
Future_r1
Value_r1
Future_r2
Value_r1

24. Automatic Continuation
A Future can be passed by parameter or by result: chains of
futures will be updated by Automatic Continuation. …
r1=a.foo()
r2=b.bar(r1)
Caller a
UPDATE
Future_r1 b
Future_r1
Value_r1
Future_r2
Value_r1
Value_r2

25. Table of Contents ProActive Runtime Active Objects Model
Future Objects and Automatic Continuation
Groups Communication
Active Objects Migration
Abstract Deployment Model
Components Infrastructure
Security

26. Group Communication
Manipulate groups of Active Objects in a simple and typed manner
Typed groups of active and remote objects.
Maintain the ‘dot ’ notation, language property
Dynamic generation of groups of results
Be able to express high-level collective communication
broadcast
scatter, gather
Based on the ProActive communication mechanism
Replication of N ‘ single ’ communications
Preservation of the « rendez-vous »
Asynchronous

27. Group Structure Stub Stub Proxy Proxy for Group Stub Proxy Jvm1 Jvm2
Remote OA
Proxy for Group
Jvm3
Stub
Proxy
Remote OA

28. Construction of a Result Group
A ag = newActiveGroup (…)
V v = ag.foo(param);
v.bar(); A V
Typed Group
Java or Active Object

29. Table of Contents ProActive Runtime Active Objects Model
Future Objects and Automatic Continuation
Groups Communication
Active Objects Migration
Abstract Deployment Model
Components Infrastructure
Security

30. Migration of Active Objects
Migration is initiated by the active object itself through a primitive: migrateTo
Can be initiated from outside through any public method
The active object migrates with:
all pending requests
all its passive objects
all its future objects
Automatic and transparent forwarding of:
requests (remote references remain valid)
replies (its previous queries will be fullfilled)

31. Characteristics and optimizations
Same semantics guaranteed (RDV, FIFO order point to point, asynchronous)
Safe migration (no agent in the air!)
Local references if possible when arriving within a VM
Tensionning (removal of forwarder)

32. Characteristics and optimizations
Same semantics guaranteed (RDV, FIFO order point to point, asynchronous)
Safe migration (no agent in the air!)
Local references if possible when arriving within a VM
Tensionning (removal of forwarder)

33. Characteristics and optimizations
Same semantics guaranteed (RDV, FIFO order point to point, asynchronous)
Safe migration (no agent in the air!)
Local references if possible when arriving within a VM
Tensionning (removal of forwarder)
direct

34. Characteristics and optimizations
Same semantics guaranteed (RDV, FIFO order point to point, asynchronous)
Safe migration (no agent in the air!)
Local references if possible when arriving within a VM
Tensionning (removal of forwarder)
direct
direct

35. Characteristics and optimizations
Same semantics guaranteed (RDV, FIFO order point to point, asynchronous)
Safe migration (no agent in the air!)
Local references if possible when arriving within a VM
Tensionning (removal of forwarder)
direct
forwarder
direct

36. Characteristics and optimizations
Same semantics guaranteed (RDV, FIFO order point to point, asynchronous)
Safe migration (no agent in the air!)
Local references if possible when arriving within a VM
Tensionning (removal of forwarder)
direct
forwarder
direct

37. Characteristics and optimizations
Same semantics guaranteed (RDV, FIFO order point to point, asynchronous)
Safe migration (no agent in the air!)
Local references if possible when arriving within a VM
Tensionning (removal of forwarder)
direct
forwarder
direct

38. Characteristics and optimizations
Same semantics guaranteed (RDV, FIFO order point to point, asynchronous)
Safe migration (no agent in the air!)
Local references if possible when arriving within a VM
Tensionning (removal of forwarder)
direct
forwarder
direct

39. API for Mobile Agents Basic primitive: migrateTo
public static void migrateTo (String u)
public static void migrateTo (Node n)
// String or ProActive node (VM)
public static void migrateTo (Object o)
// joinning another active object
Primitive to automatically execute action upon migration
public static void onArrival (String r)
// execute r upong arrival on a new Node
public static void onDeparture (String r)

40. Migration Caller Body Body Object Object Request Receiver
Reply Receiver
Reply Sender
Service
Object
RequestLine
FuturePool
Migration Manager
Body
Request Receiver
Reply Receiver
Reply Sender
Service
Object
RequestLine
FuturePool
Migration Manager
Caller

41. Migration Caller Body Body Forwarder Object Reply Receiver
Request Receiver
Reply Receiver
Body
Request Receiver
Reply Receiver
Reply Sender
Service
Object
RequestLine
FuturePool
Migration Manager
Caller
Forwarder

42. Table of Contents ProActive Runtime Active Objects Model
Future Objects and Automatic Continuation
Groups Communication
Active Objects Migration
Abstract Deployment Model
Components Infrastructure
Security

43. Abstract Deployment Model Objectives
Problem:
Difficulties and lack of flexibility in deployment
Avoid scripting for: configuration, getting nodes, connecting, etc.
A key principle:
Abstract Away from source code:
Machines
Creation Protocols
Lookup and Registry Protocols
Context:
Grid
Distributed Objects, Java
Not legacy-code driven, but adaptable to it

44. Descriptors: based on Virtual Nodes
Virtual Node (VN):
Identified as a string name
Used in program source
Configured (mapped) in an XML descriptor file --> Nodes
Operations specified in descriptors:
Mapping of VN to JVMs (leads to Node in a JVM on Host)
Register or Lookup VNs, Create or Acquire JVMs
Components Definition, Security Settings
Program Source Descriptor (RunTime)
| | | |
Activities (AO) --> VN VN --> JVMs --> Hosts
Runtime structured entities: 1 VN --> n Nodes in n JVMs

45. Mapping Virtual Nodes: example
<virtualNodesDefinition>
<virtualNode name="Dispatcher"/>
</virtualNodesDefinition>
<map virtualNode="Dispatcher">
<jvmSet>
<vmName value="Jvm1"/>
</jvmSet>
</map>
<jvm name="Jvm1">
<acquisition method="rmi"/>
<creation>
<processReference refid="jvmProcess"/>
</creation>
</jvm>
Definition of Virtual Nodes
Definitions
and mapping
Mapping of Virtual Nodes

46. Mapping Virtual Nodes: example
<processDefinition id="jvmProcess">
<jvmProcess class="org.objectweb.proactive.core.process.JVMNodeProcess"/>
</processDefinition>
<processDefinition id="rshProcess">
<rshProcess class="org.objectweb.proactive.core.process.rsh.RSHJVMProcess"
hostname="sea.inria.fr">
<processReference refid="jvmProcess"/>
</rshProcess>
JVM on the current Host
Infrastructure
informations
JVM started using RSH

47. Virtual Nodes in Programs
1. Load the descriptor file
Descriptor pad = ProActive.getDescriptor ("file://ProActiveDescriptor.xml");
2. Activate the mapping
VirtualNode vn = pad.activateMapping ("Dispatcher"); // Triggers the JVMs
3. Use nodes
Node node = vn.getNode();
...
C3D c3d = ProActive.newActive("C3D", param, node);
log ( ... "created at: " + node.name() + node.JVM() + node.host() );

48. Table of Contents ProActive Runtime Active Objects Model
Future Objects and Automatic Continuation
Active Objects Migration
Groups Communication
Abstract Deployment Model
Components Infrastructure
Security

49. Components based on Fractal Model

50. Distributed and Parallel Components
Group proxy
Group proxy A B C D

51. Components Infrastructure
JVM1
JVM2
mobility
asynchronism
component representative
component meta - objects
proxy
body
Stub_a b a

52. Components Infrastructure
JVM1
JVM2
mobility
asynchronism
component representative
component meta - objects
proxy
body b a

53. method calls are reified
Components Request
component representative
component meta - objects
method calls are reified
proxy
body b a

54. Table of Contents ProActive Runtime Active Objects Model
Future Objects and Automatic Continuation
Active Objects Migration
Groups Communication
Abstract Deployment Model
Components Infrastructure
Security

55. Security Non-functionnal security Hierarchical domains
located inside the meta-level, transparent for applications.
Hierarchical domains
Dynamic policy negotiation
Certification chain to identify users, JVMs, objects
User certificate => Application certificate => active object certificate
User private key used only once for generating application certificate
Security policies set by deployment descriptors

56. Request to an Active Object
Policy computation
Keys exchange
decrypt
encrypt
Security Manager
Security Manager
Request Receiver
Request Receiver
Request Sender
Request Sender
Body
Body
Reply Receiver
Reply Receiver
Reply Sender
Reply Sender
Service
Service
Proxy
Object
Object
Request path
Security mechanims