Flow Classifier Validation Error

[Jong-Geun Park]

Hi,
I have installed networking-sfc mitaka, but when I create the second port-chain, I faced a BadRequest Error as follow example;

BadRequest: Flow Classifier 81471676-b00f-4989-afaa-a33495c4a5a2 conflicts with Flow Classifier 1cf91d4d-6ca8-4ba3-ada6-4c00b72fd5ce in port chain 9c763348-d7f5-425f-859a-aad1d47ed0de.
Neutron server returns request_ids: ['req-47d4abd2-11f9-4ead-8b55-ddf865eb08ba']

From the source code(networking_sfc/db/sfc_db.py),
whenever a new port-chain is created, port-pair-groups and flow-classifiers should be validated whether they conflict with ones used in existing port-chains.

But, during flow classifier validation(function _validate_flow_classifiers),
only basic optional arguments(ether type, protocol, ip prefix and port range) are checked, so it causes the "flow classifier conflict error" with an existing one.

To resolve this bug, in _validate_flow_classifiers,
flowclassifier_basic_conflict need to be replaced with flow classifier_conflict function. (line number 257)

[Priya (priyaa)]

 Yes, it should check for other parameters also while validating the flow classifiers.

[Igor D.C. (igordcard)]

Looks like my ML message relates to this existing bug.
See http://lists.openstack.org/pipermail/openstack-dev/2017-January/109873.html.

More importantly, see http://eavesdrop.openstack.org/meetings/service_chaining/2017/service_chaining.2017-01-12-17.14.log.html for the IRC meeting where we discussed why this is actually not a bug, but expected behavior.

[Priya (priyaa)]

Yeah, understood this is an expected behavior. Thanks for the info.

[Bernard Cafarelli (bcafarel)]

That makes me think, we are at least 3 persons who got surprised by this behaviour, it could be worth adding a note somewhere in the documentation about that. I'll bring the question up at next meeting

[Igor D.C. (igordcard)]

+1

I'm also going to "work around it" for chains that have port pairs with correlation!=None, since the basic conflict check isn't required (and is a blocker) for that use case.

[murtazasolangi (amurtaza14)]

Also effected with same issue,
"Unable to create flow-classifier for service function chaining: The resource could not be found"

details as per this link: https://ask.openstack.org/en/question/101532/unable-to-create-flow-classifier-for-service-function-chaining-the-resource-could-not-be-found/#

Help will be highly appreciable.

Regards,
Ali