CMS MessageLogger Service: Establishing File and Stream Destinations

import FWCore.ParameterSet.Config as cms
process = cms.Process("MessageLoggerExample")
process.load("FWCore.MessageLogger.MessageLogger_cfi")
process.MessageLogger = cms.Service("MessageLogger",
       destinations   = cms.untracked.vstring(
                                                'detailedInfo'
                                               ,'critical'
                                               ,'cerr'
                    ),
       critical       = cms.untracked.PSet(
                        threshold = cms.untracked.string('ERROR') 
        ),
       detailedInfo   = cms.untracked.PSet(
                      threshold  = cms.untracked.string('INFO') 
       ),
       cerr           = cms.untracked.PSet(
                       threshold  = cms.untracked.string('WARNING') 
        )
)


# set the number of events
process.maxEvents = cms.untracked.PSet(
    input = cms.untracked.int32(200)
)
 
process.myAnalysisModule = cms.EDAnalyzer('ModuleThatIssuesMessages')
process.p = cms.Path(process.myAnalysisModule)

If messages are issued prior to the initiation of the MessageLogger service, the configuration of these destinations will not yet have occurred. Such messages will be sent to cerr.

-- SudhirMalik - 30-Aug-2011