DHCP port is changed when dhcp-agent restart

Bug #1420042 reported by Itsuro Oda on 2015-02-09
This bug affects 3 people
Affects Status Importance Assigned to Milestone

Bug Description

When dhcp-agent is restarted dhcp port may change. Obviously it causes problems since VMs don't notice this, old port may be reused, etc.

It is easy to reproduce.

before dhcp-agent restart)
$ neutron port-list --device_owner network:dhcp
| id | name | mac_address | fixed_ips |
| b72f0eb1-c1d1-4f36-a563-b4b9b5ccf562 | | fa:16:3e:f7:c3:c5 | {"subnet_id": "9071fca2-c87e-4bd5-a2c6-89c54883acac", "ip_address": ""} |

1) stop dhcp-agent
2) create port (ex. $ neutron port-create private)
3) start dhcp-agent

$ neutron port-list --device_owner network:dhcp
| id | name | mac_address | fixed_ips |
| 78653fa6-e153-41ab-b451-b40da6060415 | | fa:16:3e:b8:b6:d3 | {"subnet_id": "9071fca2-c87e-4bd5-a2c6-89c54883acac", "ip_address": ""} |

It occurs as follows:
1) network cache is initialized from state file with 'subnet empty'(!).
2) pending port-create-end RPC event is handled 'before the first sync_state'(!).
3) reload_allocations called and do 'disable' because subnet is empty.
  then release_dhcp_port RPC is issued and previous dhcp port is deleted.
4) new dhcp port is created when the first sync_state is executed.
note that network cache become normal at the first sync_state.

Itsuro Oda (oda-g) on 2015-02-09
tags: added: l3-ipam-dhcp
dql (duquanglong) on 2015-02-10
Changed in neutron:
assignee: nobody → dql (duquanglong)
Itzik Brown (itzikb1) wrote :

There is no service problem unless there are no ports left.
When an instance has to renew it's lease it sends requests for the old IP, after a few retires it sends a DHCP discovery and gets it from the 'new' DHCP server.

Changed in neutron:
status: New → Confirmed
Itsuro Oda (oda-g) wrote :


> When an instance has to renew it's lease it sends requests for the old IP,
> after a few retires it sends a DHCP discovery and gets it from the 'new' DHCP
> server.

DHCP client cannot communicate during that operation.
All clients will get this situation at next lease renewal.
It is problem.

Itzik Brown (itzikb1) wrote :

I also think it's a problem but IMHO it's not critical.
The instance will get the IP.

dql (duquanglong) on 2015-03-09
Changed in neutron:
status: Confirmed → In Progress
Changed in neutron:
importance: Undecided → Low
Changed in neutron:
status: In Progress → Fix Committed
Thierry Carrez (ttx) on 2015-06-24
Changed in neutron:
milestone: none → liberty-1
status: Fix Committed → Fix Released
Download full text (93.9 KiB)

Reviewed: https://review.openstack.org/196097
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=1cfed745d54a6ce9cb3dd4e6f454666d9e6676c2
Submitter: Jenkins
Branch: feature/qos

commit ba7d673d1ddd5bfa5aa1be5b26a59e9a8cd78a9f
Author: Kevin Benton <email address hidden>
Date: Thu Jun 25 18:31:38 2015 -0700

    Remove duplicated call to setup_coreplugin

    The test case for vlan_transparent was calling setup_coreplugin
    before calling the super setUp method which already calls
    setup_coreplugin. This was causing duplicate core plugin fixtures
    which resulted in patching the dhcp periodic check twice.

    Change-Id: Ide4efad42748e799d8e9c815480c8ffa94b27b38
    Partial-Bug: #1468998

commit e64062efa3b793f7c4ce4ab9e62918af4f1bfcc9
Author: Kevin Benton <email address hidden>
Date: Thu Jun 25 18:29:37 2015 -0700

    Remove double mock of dhcp agent periodic check

    The test case for the periodic check was patching a target
    that the core plugin fixture already patched out. This removes
    that and exposes the mock from the fixture so the test case
    can reference it.

    Change-Id: I3adee6a875c497e070db4198567b52aa16b81ce8
    Partial-Bug: #1468998

commit 25ae0429a713143d42f626dd59ed4514ba25820c
Author: Kevin Benton <email address hidden>
Date: Thu Jun 25 18:24:10 2015 -0700

    Remove double fanout mock

    The test_mech_driver was duplicating a fanout mock already setup
    in the setUp routine.

    Change-Id: I5b88dff13113d55c72241d3d5025791a76672ac2
    Partial-Bug: #1468998

commit 993771556332d9b6bbf7eb3f0300cf9d8a2cb464
Author: Kevin Benton <email address hidden>
Date: Thu Jun 25 17:55:16 2015 -0700

    Remove double callback manager mocks

    setup_test_registry_instance() in the base test case class gives
    each test its own registry by mocking out the get_callback_manager.
    The L3 agent test cases were duplicating this.

    Partial-Bug: #1468998
    Change-Id: I7356daa846524611e9f92365939e8ad15d1e1cd8

commit 0be1efad93734f11cd63fb3b7bd2983442ce1268
Author: Kevin Benton <email address hidden>
Date: Thu Jun 25 16:57:30 2015 -0700

    Remove ensure_dirs double-patch

    test_spawn_radvd called mock.patch on ensure_dirs after the
    setup method already patched it out. This causes issues when
    mock.patch.stopall() is called because the mocks are stored
    as a set and are unwound in a non-deterministic fashion.[1]
    So some of the time they will be undone correctly, but others
    will leave a monkey-patched in mock, causing the ensure_dir
    test to fail.

    1. http://bugs.python.org/issue21239

    Closes-Bug: #1467908
    Change-Id: I321b5fed71dc73bd19b5099311c6f43640726cd4

commit 0a2238e34e72c17ca8a75e36b1f56e41a3ece74e
Author: Sukhdev Kapur <email address hidden>
Date: Thu Jun 25 15:11:28 2015 -0700

    Fix tenant-id in Arista ML2 driver to support HA router

    When HA router is created, the framework creates a network and does
    not specify the tenant-id. This casuse Arista ML2 driver to fail.
    This patch sets the tenant-id when it is not passed explicitly by
    by the network_create() call from the HA r...

tags: added: in-feature-qos
tags: added: kilo-backport-potential

Change abandoned by Kyle Mestery (<email address hidden>) on branch: feature/pecan
Review: https://review.openstack.org/196701
Reason: This is lacking the functional fix [1], so I'll propose a new merge commit which includes that one.

[1] https://review.openstack.org/#/c/196711/

Download full text (171.5 KiB)

Reviewed: https://review.openstack.org/196920
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=7f759c077f8f860c13db92d2ea6b353ef6b70900
Submitter: Jenkins
Branch: feature/pecan

commit 8123144fadd7c5d5e6e56a76ea860512619a2cf6
Author: Moshe Levi <email address hidden>
Date: Sun Jun 28 14:37:14 2015 +0300

    Fix Consolidate sriov agent and driver code

    This patch add mising __init to mech_sriov/mech_driver/
    and update the setup.cfg to the new agent entrypoint

    Trivial Fix

    Change-Id: I53a527081feb78472f496675bbb3c5121d38a14a

commit 8942fccf02e6e179d47582fdb2792a1ca972da21
Author: Assaf Muller <email address hidden>
Date: Mon Jun 29 11:38:51 2015 -0400

    Remove failing SafeFixture tests

    The fixtures 1.3 release attempted to fix the fixtures resource
    leak issue, but failed to do so completely. Our own SafeFixture
    is still needed: The 1.3 release broke our SafeFixture tests,
    but not the usage of SafeFixture itself. This patch removes
    those failing tests for now to unbreak the gate. Jakub reported
    a bug on fixtures 1.3:

    We will continue to use SafeFixture until that bug is fixed
    in fixtures, at which point we will be able to require
    fixtures > 1.3.

    Change-Id: I59457c3bb198ff86d5ad55a1e623d008f0034b8f
    Closes-Bug: #1469734

commit 71dffb0a2c1720cd8233a329d32958a0160dd6f5
Author: Kevin Benton <email address hidden>
Date: Mon Jun 29 08:27:41 2015 +0000

    Revert "Removed test_lib module"

    This reverts commit 9a6536de6e1a7fe9b2552adc142e254426b82b6f.

    We pulled all of the plugins out of the tree, many of which still inherit
    from neutron test classes. This change then stated that we no longer
    support testing other plugins. I think this is a bit premature and should
    have been discussed under the subject
    "Neutron plugins can't use neutron plugin unit tests" or something

    Change-Id: I68318589f010b731574ea3bfa8df98492bab31fc

commit b20fd81dbd497e058384a0af065dd0f1fdc4c728
Author: Jakub Libosvar <email address hidden>
Date: Fri Jun 5 14:32:51 2015 +0000

    Refactor NetcatTester class

    Following capabilities were added:
       - used transport protocol is passed as a constant instead of bool
       - src port for testing was added
       - connection can be established explicitly
       - change constructor parameters of NetcatTester

    As a part of removing bool for protocol definition
    get_free_namespace_port() was also modified to match the behavior.

    Change-Id: Id2ec322e7f731c05a3754a65411c9a5d8b258126

commit 83e37980dcd0b2bad6d64dd2cb23bcd2891cafca
Author: jingliuqing <email address hidden>
Date: Sat Jun 27 13:41:54 2015 +0800

    Use REST rather than ReST

    Change-Id: I06c9deaab58c5ec13bfeec39fb8fd4b1fe21f42d

commit 1b60df85ba3ad442c2e4e7e52538e1b9a1bf9378
Author: Kevin Benton <email address hidden>
Date: Thu Jun 25 18:34:38 2015 -0700

    Add a double-mock guard to the base test case

    Use mock to patch mock with a check to prevent multiple active
    patches to the...

tags: added: in-feature-pecan

Reviewed: https://review.openstack.org/196708
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=68459f99edc2f71a5f6357c7e5594afa5883a9ea
Submitter: Jenkins
Branch: stable/kilo

commit 68459f99edc2f71a5f6357c7e5594afa5883a9ea
Author: dql <email address hidden>
Date: Mon Mar 9 12:52:11 2015 +0800

    fix DHCP port changed when dhcp-agent restart

    When DHCP server is started, the periodic task is running
    before loading cache state.The method port_update_end
    need to use the cache information, but the cache information
    has not been loaded.

    Change-Id: I0d1da11bb559b7f0f9d4428b82573fb26916a933
    Closes-Bug: #1420042
    (cherry picked from commit 3d2543d710c7071ffeb5c9857ac30a4d95695a7b)

tags: added: in-stable-kilo
Thierry Carrez (ttx) on 2015-10-15
Changed in neutron:
milestone: liberty-1 → 7.0.0
To post a comment you must log in.
This report contains Public information  Edit
Everyone can see this information.

Other bug subscribers

Remote bug watches

Bug watches keep track of this bug in other bug trackers.