using systemtap to analyze performance and funconal problems · this is only a short (non...
TRANSCRIPT
Whatdoesmymachinereallydo?
UsingSystemtaptoanalyzeperformanceandfunc9onalproblems
Studentpresenta9on@CernSchoolofCompu9ng2009MalteNuhn<malte.nuhn(at)rwth‐aachen.de>
Thisisonlyashort(nontechnical)appe9zer.Alotoftechnicaldetailswerehidden
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MonitoringGrid‐Jobs
• LHCCompu9ngGrid• Workernodesthatexecutejobs
• 8jobspermachine,novirtualiza9on
• Ques9on:– Whattrafficisproducedbywhichjob?
Job1Job2Job3
Network ?8/26/09 3Systemtap‐CernSchoolofCompu9ng‐MalteNuhn
Networktrafficpernode:
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NetworkTraffi
c(M
byte/sec)
Time(sec)
Networktrafficpernode:
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NetworkTraffi
c(M
byte/sec)
Time(sec)
Wanttoknowmoredetails
Whyisitsodifficulttolookatthedetailsofmymachine?
• YouarerunningLinux• LinuxisOpenSource• Youevenownyourhardware
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Hmm...
©Constan<neShulyupin‐hCp://www.makelinux.net/kernel_map8/26/09 7Systemtap‐CernSchoolofCompu9ng‐MalteNuhn
ProbingtheKernel#1
Differentapproaches:Longtermstabilityvs.vividdevelopment8/26/09 8Systemtap‐CernSchoolofCompu9ng‐MalteNuhn
ProbingtheKernel#2
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Probingframework:Systemtap
• Systemtapisyourfriend:– Copeswithallthedanger– Providesasimplescrip9nglanguage– Translatesscriptsintoasecurekernelmodules– Providesmaintained„Tapsets“foreverydayuse!
– Myopinion:Itisnotjustanother„geek“toy!Linuxhasalwayslackedsuchatool!
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Networktrafficpernode:
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NetworkTraffi
c(M
byte/sec)
Time(sec)
Networktrafficpernode:
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NetworkTraffi
c(M
byte/sec)
Time(sec)
Networktrafficperjob:
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NetworkTraffi
c(M
byte/sec)
Time(sec)
Seeindividualjobs
Networktrafficperjob:
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NetworkTraffi
c(M
byte/sec)
Time(sec)
Seeindividualjobs
Detailednetworktrafficforonejob:
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NetworkTraffi
c(M
byte/sec)
Time(sec)
SeecontactedHosts
Summary:Systemtap
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Addi9onalinforma9on
Systemtap:• hhp://sourceware.org/systemtap/• hhp://www.redbooks.ibm.com/abstracts/redp4469.html
• #systemtaponirc.freenode.net
LinuxKernel:• hhp://kernelnewbies.org/
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