yahoo-eng-team team mailing list archive

[Daniel Alvarez <1739798@xxxxxxxxxxxxxxxxxx>]

Public bug reported:

When a network is deleted, its segments are also deleted [0]. For each
segment, it will notify about resources.SEGMENT and events.AFTER_DELETE
[1] which will turn out in calling update_network_postcommit [2].

This should be avoided since drivers expect their postcommit methods to
be called with no open sessions to the database. There should be
separate callbacks for segments so that there's no transactions opened
to the database in any of the postcommit calls.

We detected this in networking-ovn driver because we're attempting to
bump revision numbers in a separate table in Neutron database when a
network is updated but we can't commit that change to the database
because there's already an open session on a network delete operation.
This may be affecting other drivers as well.

[0] https://github.com/openstack/neutron/blob/6cdd079f8f3e6994734fa806b3c819cecb5f521a/neutron/services/segments/db.py#L315
[1] https://github.com/openstack/neutron/blob/6cdd079f8f3e6994734fa806b3c819cecb5f521a/neutron/services/segments/db.py#L178
[2] https://github.com/openstack/neutron/blob/6cdd079f8f3e6994734fa806b3c819cecb5f521a/neutron/plugins/ml2/plugin.py#L1917

** Affects: neutron
     Importance: Undecided
         Status: New

** Description changed:

- When a network is delete, its segments are also deleted [0]. For each
+ When a network is deleted, its segments are also deleted [0]. For each
  segment, it will notify about resources.SEGMENT and events.AFTER_DELETE
  [1] which will turn out in calling update_network_postcommit [2].
  
  This should be avoided since drivers expect their postcommit methods to
  be called with no open sessions to the database. There should be
  separate callbacks for segments so that there's no transactions opened
  to the database in any of the postcommit calls.
  
  We detected this in networking-ovn driver because we're attempting to
  bump revision numbers in Neutron database when a network is updated but
  we can't commit that change to the database because there's already an
  open session. This may be affecting other drivers as well.
  
  [0] https://github.com/openstack/neutron/blob/6cdd079f8f3e6994734fa806b3c819cecb5f521a/neutron/services/segments/db.py#L315
  [1] https://github.com/openstack/neutron/blob/6cdd079f8f3e6994734fa806b3c819cecb5f521a/neutron/services/segments/db.py#L178
  [2] https://github.com/openstack/neutron/blob/6cdd079f8f3e6994734fa806b3c819cecb5f521a/neutron/plugins/ml2/plugin.py#L1917

** Description changed:

  When a network is deleted, its segments are also deleted [0]. For each
  segment, it will notify about resources.SEGMENT and events.AFTER_DELETE
  [1] which will turn out in calling update_network_postcommit [2].
  
  This should be avoided since drivers expect their postcommit methods to
  be called with no open sessions to the database. There should be
  separate callbacks for segments so that there's no transactions opened
  to the database in any of the postcommit calls.
  
  We detected this in networking-ovn driver because we're attempting to
- bump revision numbers in Neutron database when a network is updated but
- we can't commit that change to the database because there's already an
- open session. This may be affecting other drivers as well.
+ bump revision numbers in a separate table in Neutron database when a
+ network is updated but we can't commit that change to the database
+ because there's already an open session on a network delete operation.
+ This may be affecting other drivers as well.
  
  [0] https://github.com/openstack/neutron/blob/6cdd079f8f3e6994734fa806b3c819cecb5f521a/neutron/services/segments/db.py#L315
  [1] https://github.com/openstack/neutron/blob/6cdd079f8f3e6994734fa806b3c819cecb5f521a/neutron/services/segments/db.py#L178
  [2] https://github.com/openstack/neutron/blob/6cdd079f8f3e6994734fa806b3c819cecb5f521a/neutron/plugins/ml2/plugin.py#L1917

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https://bugs.launchpad.net/bugs/1739798

Title:
  update_network_postcommit is being called from
  delete_network_precommit with an open session

Status in neutron:
  New

Bug description:
  When a network is deleted, its segments are also deleted [0]. For each
  segment, it will notify about resources.SEGMENT and
  events.AFTER_DELETE [1] which will turn out in calling
  update_network_postcommit [2].

  This should be avoided since drivers expect their postcommit methods
  to be called with no open sessions to the database. There should be
  separate callbacks for segments so that there's no transactions opened
  to the database in any of the postcommit calls.

  We detected this in networking-ovn driver because we're attempting to
  bump revision numbers in a separate table in Neutron database when a
  network is updated but we can't commit that change to the database
  because there's already an open session on a network delete operation.
  This may be affecting other drivers as well.

  [0] https://github.com/openstack/neutron/blob/6cdd079f8f3e6994734fa806b3c819cecb5f521a/neutron/services/segments/db.py#L315
  [1] https://github.com/openstack/neutron/blob/6cdd079f8f3e6994734fa806b3c819cecb5f521a/neutron/services/segments/db.py#L178
  [2] https://github.com/openstack/neutron/blob/6cdd079f8f3e6994734fa806b3c819cecb5f521a/neutron/plugins/ml2/plugin.py#L1917

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