1. Agent Teams in Grid Resource Brokering and Management (preliminary considerations)

2. Introduction The Grid  what?  why? Local Grid  in a laboratory / company Global Grid  the P2P nightmare  nodes appear and disappear  node load can change radically  no problem for SETI@HOME  problem when you need QoS SLA

3. Agents in grids today B. Di Martino and O. Rana  static and mobile agents in the system (MAGDA)  agents visit sites to find resources (services) visits based on exchanges of messages with nodes executes a task or a part of it  AGLETS-based / no economic model S. Manvi et. al.  attempt at adding economic model  single agent moves, negotiates, executes  heavily based on mobility

4. Comments / reminders Mobility can be costly  there is no free lunch Single resource provider  difficult to assure QOS / SLA Economic model is “necessary” (Buyya, 2000) Proposed solution  agent teams  “one for all and all for one”

5. Assumptions Agents work in teams Each team has a team leader (local master – Lmaster) Incoming Workers can join any team based on their criteria of joining Teams can accept workers based on their own criteria of acceptance Each Worker can (if needed) play role of Lmaster Decisions about joining and accepting will utilize contract net protocol and multi-criterial analysis Yellow-page method for matchmaking (provided by the CIC agent)  other approaches possible

6. Use case diagram of the system

7. Structure of a work-team Each team has an Lmaster and a mirror Lmaster (LMirror)  if only one agent  Lmaster  next incoming agent becomes Lmirror  LMirror becomes Lmaster if Lmaster fails Lmaster keeps its role as long as it can handle the workload If LMirror “disappears” Lmaster appoints one of slaves to be a mirror Lmaster and LMirror check each other existence in regular intervals Each subsequent agent becomes a worker

8. Finding team to... Lagent checks with the CIC who  it can join  does the work it needs Lagent sends representatives to negotiate Lagent makes decision  which team to join  which team will do the job Lagent collects data to be used (in the future) in MCDM

9. CIC architecture:#1 task-per-thread paradigm CICAgent picks requests from the JADE-provided message queue and enqueues them into the request queue

10. CIC architecture #2 local CICDbAgents the CIC agent picks requests form the JADE message queue and enqueues them into the internal request queue each CICDbAgent completes one task (request) at a time upon completion, results are sent back to the CICAgent

11. CIC architecture #3 database agents are located on remote machines contributing additional computational power and allowing CICDbAgents to work without stealing resources from the CICAgent

12. About experiments 4 Querying Agents (QA), requesting the CIC to perform SPARQL resource queries Each QA was running concurrently on separate machine, and was sending 2,500 requests and receiving query-results All experimental runs were coordinated by the Test Coordinator Agent (TCA). Before each test, remote JADE agent containers were restarted to provide equal environment conditions 11 AMD Athlon 2500+, 512MB RAM machines running Gentoo Linux and JVM 1.4.2. Computers were interconnected with a 100Mbit LAN

13. Experimental results – different CIC architectures multi-threaded (pull) multi-agent with local CICDbAgents (push) multi-agent with distributed CICDbAgents (push) 10,000 queries

14. Architecture with CIC Internal Agent (CICIA)

15. Final comparisons Left panel – remote agents with and without CICIA – throughput Right panel – remote agents vs. threads – processing time

16. Resource ontology :Computer :a owl:Class. :hasCPU :a owl:ObjectProperty; rdfs:range :CPU; rdfs:domain :Computer. :CPU :a owl:Class. :hasCPUFrequency :a owl:DataProperty; rdfs:comment "in GHz"; rdfs:range xsd:float; rdfs:domain :CPU. :hasCPUType :a owl:ObjectProperty; rdfs:range :CPUType; rdfs:domain :CPU. :CPUType :a owl:Class. Intel :a :CPUType. AMDAthlon :a :CPUType. :hasMemory :a owl:DatatypeProperty; rdfs:comment "in MB"; rdfs:range xsd:float; rdfs:domain :Computer. :hasUserDiskQuota :a owl:DatatypeProperty; rdfs:comment "in MB"; rdfs:range xsd:float; rdfs:domain :Computer. :LMaster :a owl:Class; :hasContactAID :a owl:ObjectProperty; rdfs:range xsd:string; rdfs:domain :LMaster. :hasUserDiskQuota :a owl:DatatypeProperty; rdfs:comment "in MB"; rdfs:range xsd:float; rdfs:domain :Computer.

17. Sample resource description :LMaster3 :hasContactAID "monster@e-plant:1099/JADE"; :hasWorker :PC2929. :PC2929 :a :Computer; :hasCPU [ a :CPU; :hasCPUType :Intel; :hasCPUFrequency "3.7"; ] ; :hasUserDiskQuota "400"; :hasMemory "512".

18. SPARQL query PREFIX : SELECT ?contact WHERE { ?lmaster :hasContactAID ?contact; :a :LMaster; :hasWorker [ :a :Computer; :hasCPU [ a :CPU; :hasCPUType :Intel; :hasCPUFrequency ?freq; ]; :hasUserDiskQuota ?quota; :hasMemory ?mem; ]. FILTER (?freq >= 3.2) FILTER (?quota >= 350) FILTER (?mem >= 256) }

19. LMaster  CIC interactions

20. End of Agents in Grid Part QUESTIONS? Looking for collaborators  papers available at: http://agentlab.swps.edu.pl