infso-ri-508833 enabling grids for e-science gridice: a monitoring service for grid systems sergio...

INFSO-RI-508833

Enabling Grids for E-sciencE

www.eu-egee.org

GridICE: a monitoring service for Grid SystemsSergio AndreozziINFN (Italy)[email protected]

TERENA Networking Conference 2005, 8 June

TNC2005, Poznan, 8 june 2005 2


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OUTLINE

• What is a Grid• What is Monitoring

– terms and concepts– the process of monitoring

• Use cases for a Grid Monitoring System• GridICE

– Architecture– Screenshots



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What is a Grid

• Virtualization of users and resources

Site A Site B

Grid system

• Mapping virtual resources to physical resources

• Mapping virtual users to physical users



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What is a Grid

Grid Systems:

• enable the secure sharing of resources (e.g., execution

environments for jobs, storage areas, databases)

• Shared resources

– Can be geographically dispersed

– Can be heterogeneous

– Can belong to different administrative domains

– Their composition can dynamically change

– Can be accessed by remote users



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What is MonitoringTerms and Concepts

• Grid Monitoring– the activity of measuring significant grid resources

related parameters – in order to

analyze usage, behavior and performance of the grid detect and notify

• fault situations• contract violations (SLA)• user-defined events



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What is MonitoringTerms and Concepts

• Measurement: the process by which numbers or symbols are assigned to feature of an entity in order to describe them according to clearly defined rules

• Event: collection of timestamped data associated with the attribute of an entity [2]

• Event schema (or simply schema): defines the typed structure and semantics of all events so that, given an event type, one can find the structure and interpret the semantics of the corresponding event [2]



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The four main phases of monitoring

Generation

Distributing

Presenting

Pro

cessin

g

sensors enquiring entities and encoding the measurements according to a schema (active/passive, intrusive/non-intrusive)

transmission of the events from the source to any interested parties (data delivery model: push vs. pull; periodic vs. aperiodic; unicast vs. l-to-N)

Processing and abstract the number of received events in order to enable a the consumer to draw conclusions about the operation of the monitored system

e.g., filtering according to some predefined criteria, or summarising a

group of events



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Use cases for Grid monitoring

• Virtual Organization:1. visualize at various aggregation levels the actual set of

resources accessible to its members;

2. Assess how Grid mapping functionalities from virtual to physical resources and users meet the members’ demands

3. analyze data retrospectively to understand how to improve the effectiveness of VO applications running in a Grid, as the target machine for different executions of the same application can vary over time



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Use cases for Grid monitoring

• Site Administrator:– Visualize the managed Grid services in order to see how they

are being used/performing (possibly divided by VO)

• User:– Is my job “working” (e.g., consuming CPU?)

• Grid Operation Center:– Status of Grid services (e.g., WMS, Service Discovery, CE, SE)– Free/busy resources per site/per VO at a given time– Timely notification about fault situations



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GridICE: architectural insight



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Monitoring: generating events

• generation of events:– Sensors: typically perl scripts or c programs– Schema:

GLUE Schema v.1.1 + GridICE extension• System related (e.g., CPU load, CPU Type, Memory size)

• Grid service related (e.g., CE ID, queued jobs)

• Network related (e.g., Packet loss) [5]

• Job usage (e.g., CPU Time, Wall Time)

– All sensors are executed in a periodic fashion



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Monitoring: distributing

• distribution of events:– Hierarchical model

Intra-site: by means of the local monitoring service • default choice, LEMON (http://www.cern.ch/lemon)

Inter-site: by offering data through the Grid Information Service Final Consumer: depending on the client application

– Mixed data delivery model Intra-site: depending on the local monitoring service (push for

lemon) Inter-site: depending on the GIS (current choice, MDS 2.x, pull) Final consumer: pull (browser/application), push (publish/subscribe

notification service)



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Example deployment in LCG2



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GridICE Architecture

Resource

Site Publisher

Sensor

event collector

event provider

consumer

publisher

WAN

LAN

publishers

Lemon srv

Lemon agt

LDAP Client

MDS GRIS

scripts

HTTP:HTML/XMLNS

GridICE on LCG 2

logical components

roles

GridICE Server

Consumer

WAN

xML: pull,aperiodic,unicastNS: push,aperiodic,unicast

Browser

Data delivery model

pull,periodic,unicast

push,periodic,unicast

application

consumers



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GridICE on gLite

Resource

Site Publisher

Sensor

event collector

event provider

consumer

publisher

WAN

LAN

publishers

Lemon srv

Lemon agent

CEMon

scripts

HTTP:HTML/XMLNS

GridICE on gLite

logical components

roles

GridICE Server

Consumer

WAN

xML: pull,aperiodic,unicastNS: push,aperiodic,unicast

Browser

Data delivery model

pull,periodic,unicast

push,periodic,unicast

RGMA

application

consumers

MDS2

consumers

G



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GridICE Server

Persistent storage

Discovery Consumers Scheduler

XSLT->HTML

XML abstraction

XML Notification S.Charts

components that need to be revised when migrating to gLite

[6]



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GridICE >> Site View >> General



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GridICE >> Site View >> Host Summary



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Running/waiting jobs for a VO



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Current release status

– Integrated and deployed with LCG 2.x– Last server release v.1.8.0.rc1– Last sensor release v.1.5.1.pl2– Installed servers are monitoring Grid resources in the scope of:

Grid.it GILDA LCG LCG South-West federation LCG South-East federation SEE-GRID E-grid project CMS experiment ATLAS experiment



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Next steps

• Avoid proliferation of sensors (especially for intrusive ones)– Planned integrated with metering system of DGAS (Grid

accounting)

• Dealing with site policies as regards privacy of log files– Sensors should provide mechanisms to allow sites to push the

data of interest

• Enable security of monitoring data– in particular, VO and role based authorization at the producer

levels (e.g., the VO manager of CMS can read all info about the jobs that are running by CMS users)

• Dealing with heterogeneous producer interfaces• Provide a more flexible job monitoring mechanism



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CONCLUSION

• Monitoring of Grid systems is a complex activity in metering, distributing and presenting

• GridICE has been designed on the basis of the requirements collected by a wide variety of users

• The experience in production environments is positive

• New challenges for the evolution in the context of gLite are harmonization of metering, security and dealing with multiple producers



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References

[1] S. Andreozzia, N. De Bortoli, S. Fantinel, A. Ghiselli, G. L. Rubini, G. Tortone, M. C. Vistoli GridICE: a monitoring service for Grid systems, Future Generation Computer System 21 (2005) 559–571

[2] B. Tierney, R. Aydt, D. Gunter, W. Smith, M. Swany, V. Taylor, R. Wolski, A Grid Monitoring Architecture, GFD-I.7

[3] S. Zanikolas, R. Sakellariou, A taxonomy of grid monitoring systems, Future Generation Computer Systems 21 (2005) 163–188

[4] M. Franklin, S. Zdonik, “Data In Your Face”: Push Technology in Perspective, ACM SIGMOD ’98, Seattle, WA, USA

[5] S. Andreozzi, A. Ciuffoletti, A. Ghiselli, C. Vistoli. Monitoring the connectivity of a Grid. Proceedings of the 2nd International Workshop on Middleware for Grid Computing (MGC 2004) in conjunction with the 5th ACM/IFIP/USENIX International Middleware Conference, Toronto, Canada, October 2004.

[6] S. Andreozzi, N. De Bortoli, S. Fantinel, G.L. Rubini, G. Tortone. Design and Implementation of a Notification Model for Grid Monitoring Events. CHEP04, Interlaken (CH), Sep 2004

Dissemination: http://grid.infn.it/gridice

infso-ri-508833 enabling grids for e-science gridice: a monitoring service for grid systems sergio...

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