openstack team mailing list archive

[Gabe Westmaas <gabe.westmaas@xxxxxxxxxxxxx>]

On 6/12/12 12:32 PM, "Jay Pipes" <jaypipes@xxxxxxxxx> wrote:

>On 06/12/2012 01:27 AM, Gabe Westmaas wrote:
>> In nova we use a request ID to to help in finding all logs associated
>>with
>> a particular request, and this has proven to be extremely useful when
>> debugging issues.  This should be taken a bit further, in two different
>> directions.
>>
>> First, I'd like to see the request ID stored along with the any faults
>> that are registered, and I'd like to see that request ID returned in the
>> fault data.  Returning it in the fault data can start as an extension
>>for
>> now, and that should be able to move forward into the API pretty easily.
>
>This is a no-brainer. ++
>
>> Second, I'd like to figure out how we can extend this concept to all the
>> openstack services.  I see two competing desires here.  First, we want
>>to
>> know about a particular request to a given service and second we want to
>> know about an overall transaction across all services.  So, for
>>example, a
>> single create server request may cause multiple requests to glance, and
>> depending on the issue, it would be great to both tie those together or
>> investigate separately.  To this end, I'd like to see both a request ID
>> and a transaction ID.  I'd like to see both these items in log, and I'd
>> like all OpenStack services to obey the rule that if the transaction ID
>>is
>> set, don't reset it to anything else, but always add a request ID.
>
>OK, so the request ID would be specific to a service (e.g. Nova, Glance,
>but not nova-api and nova-compute) and the transaction ID would be
>across all services?
>
>Or would the request ID change from nova-api to nova-scheduler to
>nova-compute?

I was definitely thinking the first of these two options, but I suppose we
should talk that out a little bit.  Seems like a likely line is when a new
HTTP call is made, the request-id is reset.  This allows us to disallow
passing in a request-id for all web services, which would lend itself well
to a common middleware.  That is to say, users of an API can pass in a
transaction ID (which means the transaction ID could originate from the
customer, if that's helpful to them) and the request id would always get
set to a random UUID any time it passed through this middleware.

Thus the request ID is the same from nova api to scheduler to compute to
network.  However, glance api and glance registry would each have unique
request IDs, but a common transaction ID.

>
>> Thoughts?  Do you buy the need for both a request ID and a transaction
>>ID?
>
>Sure. Just curious where you think the dividing line is -- the project
>(Nova, Glance) or the service/workers (nova-api, nova-compute, etc).
>
>Best,
>-jay
>
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