Definition: Event Propagation Notification: –Publisher declares & then subscribe –Conditional, more structure, standards focused, dynamic –Zero to many, message oriented middleware, asynch Callbacks: –Subscriber wants information –Conditional, Adhoc structure, specific function/data –Very loosely defined structure, Opaque data –One to one, ‘static’ configuration, Sync & two way Two aspects/model of the same thing? –GL: Subscribe to monitoring events

What is happening to my job? Why: –Has it got sufficient resources? –Has it gone wrong? –User or application defined? Logging: –MyJobLog or TheirContainerLog? Clients of ‘central’ notification system Who stores the logs (may be needed for future analysis) May involve more than just the client & server –e.g. 3 rd party transfer debugs. Security & access Ownership of information Service interface to access stored logs Log lifetime –Events need to correlated: Across sites: Different Administrators & Timezones Invocations: Comparison between the one that worked & today’s that didn’t Environment: Library upgrade, new software –Events need to be classification: Type & level & dynamically alter configuration during runs

Technology/Implementation WS-BaseFaults: –Tries to standardise… –Fault Types: HTTP SOAP Wanted: Standard elements for common stuff: stack, hostname, message delivered, … Axis: Commons-logging Java API Implementations: log4j, SmartFrog, Netlogger (??) –Need to change logging during the run. LOGGING EVERYWHERE!

Deployment/Operational Client Notification through firewalls –Firewall: Assume outgoing connections OK! –Firewall: Probably block incoming connections Realtime: Tunnel through firewall to client server, e.g. IM Delivery: Collect from server rekay (store & fore), e.g. –SMTP through firewall Client needs to run a service –Heavyweight –Application may be single threaded and poll external event store

Debugging Correlation: –Logging of failed past runs –Environment of past runs –Current operational status & behaviour? Datamining to investigate issues –Performance –Intrusion –Failure

What’s Missing? XML Logging Definition Agreement on definitions –The O word OGSA logging