[nvo-techwg] A couple of questions on Support Interface for Logging
dtody at nrao.edu
Wed Dec 7 07:18:25 PST 2005
I agree with the concern about logging being tied into VOStore. Also,
it is not clear if a logging interface needs to be built into every
service instance, rather it might be associated with a server or site.
Some comments I posted after the NVO team meeting several weeks ago:
o The current proposal is that services upload log information
periodically to a central site. However, by definition services
respond to requests, so it is not clear if we should expect a
service to run indefinitely and act as a client.
o Rather than have each service do its only logging, it might make
more sense for a "site" or server to be responsible for logging.
For example, it will often be the case that a site/server will
support many services. One would like to be able to have the
services just send log messages to a central log daemon on the
local server. This could then communicate logging information
to the central harvesting site. In this case since we are not
talking about a service, a push approach would be reasonable.
o Whether or not logging should use VOStore(VOSpace) is an issue.
It has been suggested that VOStore should be used since the logs
are so large. However, logging is a low level capability, and
VOStore is a complex high level capability. It would seem to
violate good system design principles for a low level function
to depend upon higher level capabilities.
I agree that logging is important, both to instrument the system for
engineering purposes, and to monitor activity for funding purposes. But it
should be optional for individual service implementations. If logging is
provided by a separate centralized logging service, with messages being
sent from each service instance, then the only impact on the service
instance is support for an optional message channel to the logger.
On Wed, 7 Dec 2005, KevinBenson wrote:
> I had a few questions on the updated Support Interface.
> 1.) Logging now going to VOStore?
> This seems a little too much, both the server and client have to do
> complicated tasks: sending/retrieving files to and from VOStore, generating
> request id's, e-mail Notifications, either client or server will need to
> specify filenames in the VOStore, convert your results to csv. All seem to
> be a little complicated.
> I would prefer that we keep it simple can we just have it as synchronous
> and have it immediately returned. I suspect there is a lot of logging going
> on, but we should be able to return up to a month worth of data in a
> synchronous call. How about simply restricting in the spec the fromDate and
> toDate should not be more than a 30 days between the dates. And for the
> return of the data it can now be an actual simple xml schema of all your
> optional&required values.
> **The next question are really only if we kept the Logging interface simple
> with no VOStore.
> 2.) Will we need security on the logging?
> If we did keep it simple is there anything in the response that would
> require security? I can only possibly see clientIP. Be nice not to have
> security at all on Logging interface. Or is there other hidden reasons you
> might need authentication into the Logging interface.
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