Logging suggestion

[Paul Harrison]

I think that I agree with Doug and Kevin on this - imposing a 
requirement for a logging interface on *every* service is a significant 
barrier to implementation, as this sort of interface does not fit easily 
with existing low level logging libraries, so some sort of adapter layer 
would have to be written in every service to gather and send the 
requested information.

Having a localised logging service that was able to accept log 
information in a number of ways that recognised the facilities of 
existing log libraries - e.g. in java log4j has serveral methods 
available for remote logging, that are not necessarily web services. The 
implementer of a web service could chose the easiest way to send the log 
information to the localised log collecting/storing server - and I think 
that push is more appropriate.

In this way there could be a small number of implementations of the log 
collecting server, which could then potentially do more complex actions 
such as periodically storing gathered logs in a vostore.


Doug Tody wrote:
> Hi Ani -
> 
> On Wed, 7 Dec 2005, Ani Thakar wrote:
> 
>> There are two different logging services that we are talking about here,
>> I think:
>>
>>     - site logging
>>     - VO logging
>>
>> The first is the logging service at a given site that may or may not
>> provide a query interface for users to view the logged data.  This logs
>> all the services at a given site (e.g. STScI).
>>
>> The second is the VO-wide log harvesting that collects the logs from all
>> the VO services in a VO domain (e.g. NVO).
>>
>> Which one do you mean by "centralized logging service"?
> 
> 
> The suggestion was that the VO logging interface and functionality not
> be provided by individual services, but by some centralized site logging
> service (specific to VO, not httpd logging or some such)) which the
> domain-wide VO log harvestor can access.
> 
> 
>> The logging interface in the support interfaces draft only deals with
>> the minimum that any site or service needs to do to get its log data
>> harvested to the VO logging VOStore.
>>
>> It's fine if each site has a central logging service that has a log
>> harvesting interface hanging off it that the VO log harvester can use to
>> retrieve log data from it periodically.  Each individual service does
>> not need to support a log harvesting interface.
> 
> 
> This is what was meant by a "centralized logging service" for a site.
> 
> 
> I still think it would be good if low level infrastructure capabilities 
> like
> service registration, logging, heartbeat, etc., could function 
> independently
> of complex high level data management functionality such as VOStore.
> 
>     - Doug
> 


-- 
Paul Harrison
ESO Garching
www.eso.org