CERN IT Department

CH-1211 Geneva 23

Switzerlandwww.cern.ch/

it

A proposal for improving Job Reliability Monitoring

GDB2nd April 2008

CERN IT Department

CH-1211 Genève 23

Switzerlandwww.cern.ch/

it

InternetServices

Problem Statement

• We would like to be able to gather job state transitions from all jobs submitted in WLCG resources– EGEE

• RB + WMS submitted jobs• Jobs submitted directly to a CE (via condor_g)

– OSG• Jobs on a OSG CE for WLCG VOs

– Nordugrid• ARC CE

• Use this to calculate resource reliability– And use for debugging e.g. Dashboards

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CERN IT Department

CH-1211 Genève 23

Switzerlandwww.cern.ch/

it

InternetServices

Principles

• Only gather this information once– Propagate to interested parties

• Using existing systems and expertise where possible– Don’t try and deploy components on every

WMS/RB/L&B/CE/…– Get ‘cooked’ data from the systems

• Hook up with Pilot Jobs– Linkage between pilot and experiment jobs as a

‘state change’• ‘Job Wrapper tests’ fit in here too

– They’re just another state change3

CERN IT Department

CH-1211 Genève 23

Switzerlandwww.cern.ch/

it

InternetServices

Current situation - Gridview

• Currently mines L&B log files, and sends them via R-GMA

• Loses many records• Hacks to ‘finish’ unfinished jobs after 24

hours– Inaccurate results

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CERN IT Department

CH-1211 Genève 23

Switzerlandwww.cern.ch/

it

InternetServices

Current situation - Dashboard

• Jobs reported via experiment frameworks– Gathers from many sources – Imperial College

XML files, job submission tools, monAlisa reporting from jobs, R-GMA

• But some missing information for condor_g jobs– info between submission and user job starting on

WN– Job aborted

• Some work done (Sergey Belov/Dubna) on reporting state changes inside condor_g

Presentation title - 5

CERN IT Department

CH-1211 Genève 23

Switzerlandwww.cern.ch/

it

InternetServices

Proposal

• Use WLCG Monitoring infrastructure (MSG) for collecting and transporting the data– Messaging system– Standard message formats

• Work with expert groups to instrument the job submission systems

• Visualization by Gridview + Dashboards

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CERN IT Department

CH-1211 Genève 23

Switzerlandwww.cern.ch/

it

InternetServices

Effort

• Provide some effort to do the instrumentation– Coordination – WLCG Monitoring (D Rodrigues)– Messaging system integration - Gridview– EGEE WMS – L&B , Gridview– Condor-G – Condor team, Dashboard team– OSG CE – through OSG participation in the Joint

Monitoring Group (OSG Operations (Rob Quick), measurements & metrics (Brian Bockelman)

Presentation title - 7

CERN IT Department

CH-1211 Genève 23

Switzerlandwww.cern.ch/

it

InternetServices

EGEE

• L&B Notifications means we don’t have to run components mining L&B logfiles– Consumer of notifications can be remote

• L&B is stated to scale for our needs– Tested at >1m records/day– Testing of integrating with notifications underway

by gridview team• Message formats already defined

– Old log mining approach will all be moved to messaging system to free GridView from R-GMA dependency

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CERN IT Department

CH-1211 Genève 23

Switzerlandwww.cern.ch/

it

InternetServices

condor_g

• condor_g submitter instrumented to create L&B messages– Done by a separate listener process that is

started by condor_g– Limited subset of condor_g state changes will be

sent• Listener/reporter can use different transport

for reporting– Currently monalisa as a transport layer– Will migrate to WLCG messaging system

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CERN IT Department

CH-1211 Genève 23

Switzerlandwww.cern.ch/

it

InternetServices

EGEE Architecture

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CERN IT Department

CH-1211 Genève 23

Switzerlandwww.cern.ch/

it

InternetServices

OSG

• Gratia is used to transport messages inside OSG

• A Gratia-MSG Bridge could be implemented– Similar to the RSV bridge used for OSG

availability• Plan to include discussion in the upcoming

EGEE-OSG-WLCG design meeting in Madison at the end of May– Hope to further collaborate with OSG on the

infrastructure for the analysis of the collected data, dashboards etc.

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CERN IT Department

CH-1211 Genève 23

Switzerlandwww.cern.ch/

it

InternetServices

Nordugrid

• Nordugrid– Currently only Nordugrid Job info is via ATLAS

production DB– How do we get information from the CE?

• Will look to implement a similar bridge if needed– Need to work through the technical details with

the experts– Discussion yet to start…

Presentation title - 12

CERN IT Department

CH-1211 Genève 23

Switzerlandwww.cern.ch/

it

InternetServices

Pilot Jobs

• L&B client resides on every worker node• Can be used to submit additional messages

to L&B for a job– Timestamps +environment for Job Wrapper

start/end– Timestamp of handover to user job– Linkage of pilot job to experiment job ID– …

• Benefit is that it’s all in one coherent data structure for a given job

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CERN IT Department

CH-1211 Genève 23

Switzerlandwww.cern.ch/

it

InternetServices

Summary

• Propose a more coherent approach to mining job state changes– Uses expert knowledge where possible to ‘cook’

the data into a useful structure• Fits the principles of the WLCG monitoring

activity– Use common message system components– Split the work across the relevant teams

• What have we missed?– Your feedback essential…

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