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Why do two cinder-scheduler_fanout queues have no consumer?

asked 2015-09-24 09:35:56 -0500

DanielJ gravatar image

Hi everyone,

when I had a look at the RabbitMQ queues on my controller nodes, I was surprised seeing three cinder-scheduler_fanout queues. Two of them have no consumer leading to continuously increasing queue sizes. Each queue already requires more than 1 GB of memory. I have manually purged the queues but there are still new messages arriving.

The third queue receives messages, too but they are directly consumed.

In order to prevent the queues to run out of memory, I tried to identify which service is sending the messages to theses queues. But I had no luck. Does anyone of you has an idea which service is sending messages on these queues and how I can reconfigure it such that these queues are not used any more?

Cloud Setup

  • Openstack Juno on Ubuntu 14.04
  • 3 controller nodes
    • each running RabbitMQ
    • one controller running cinder-scheduler and cinder-api
  • 3 storage nodes
    • running a ceph cluster as storage backend
    • each runs a ceph monitor and a cinder-volume

Example Message Sent to Queues

"oslo.message": "{
    \"_context_domain\":            null, 
    \"_context_request_id\":        \"req-4b04bf3f-5efc-4cf3-84e2-8c594fa027a6\", 
    \"_context_quota_class\":       null, 
    \"_context_service_catalog\":   [], 
    \"_context_auth_token\":        null, 
    \"_context_user_id\":           null, 
    \"_context_is_admin\":      true, 
    \"version\":                \"1.0\", 
    \"_context_timestamp\":     \"2015-03-04T13:21:42.034252\", 
    \"_context_project_domain\":    null, 
    \"_context_user\":          null, 
    \"method\":             \"update_service_capabilities\", 
    \"_context_remote_address\":    null, 
    \"_context_roles\":         [\"admin\"], 
    \"args\":                   {
        \"service_name\":   \"volume\", 
        \"host\":           \"storage3@rbd-storage\", 
        \"capabilities\":       {
            \"volume_backend_name\":    \"RBD_STORAGE\", 
            \"free_capacity_gb\":       239266, 
            \"driver_version\":     \"1.1.0\", 
            \"total_capacity_gb\":      244822, 
            \"reserved_percentage\":    0, 
            \"vendor_name\":        \"Open Source\", 
            \"storage_protocol\":       \"ceph\"
    \"_unique_id\":             \"014c9c97b86b4c6b9eb8f7207af1ba5b\", 
    \"_context_project_name\":      null, 
    \"_context_read_deleted\":      \"no\", 
    \"_context_user_identity\":     \"- - - - -\", 
    \"_context_tenant\":            null, 
    \"_context_project_id\":        null, 
    \"_context_user_domain\":       null
"oslo.version":                 "2.0"


rootwrap_config = /etc/cinder/rootwrap.conf
api_paste_confg = /etc/cinder/api-paste.ini
volume_name_template = volume-%s
#verbose = True
#debug = true
auth_strategy = keystone
state_path = /var/lib/cinder
lock_path = /var/lock/cinder

rpc_backend = rabbit
rabbit_hosts = <rabbit1>,<rabbit2>,<rabbit3>
rabbit_password = <rabbit_password>
rabbit_userid = <rabbit_user>
rabbit_virtual_host = /
rabbit_durable_queues = False
rabbit_ha_queues = true

auth_strategy = keystone

my_ip = <myIP>
glance_host = <glanceHostIP>
glance_api_version = 2

backup_driver = cinder.backup.drivers.ceph
backup_ceph_conf = /etc/ceph/storage.conf
backup_ceph_user = cinder-backup
backup_ceph_chunk_size = 134217728
backup_ceph_pool = backups_storage
backup_ceph_stripe_unit = 0
backup_ceph_stripe_count = 0
restore_discard_excess_bytes = true
# the topic volume backup nodes listen on (string value)


volume_driver = cinder.volume.drivers.rbd.RBDDriver
rbd_pool = volumes_storage
rbd_ceph_conf = /etc/ceph/storage.conf
rbd_flatten_volume_from_snapshot = false
rbd_max_clone_depth = 5
rbd_store_chunk_size = 4
rados_connect_timeout = -1
rbd_user = <user>
rbd_secret_uuid = <uuid>

volume_driver = cinder.volume.drivers.rbd.RBDDriver
rbd_pool = volumes_compute
rbd_ceph_conf = /etc/ceph/storage.conf
rbd_flatten_volume_from_snapshot = false
rbd_max_clone_depth = 5
rbd_store_chunk_size = 4
rados_connect_timeout = -1
rbd_user = <user>
rbd_secret_uuid = <uuid>

auth_uri = <keystone>/v2.0
identity_uri = <keystoneIdentit>
admin_tenant_name = <tenantName>
admin_user = <userName>
admin_password = <userPassword>

connection = <databaseConnection>


fsid = <fsid>
mon_initial_members = storage1, storage2, storage3
mon_host = <host1>,<host2>,<host3>
auth_cluster_required = cephx
auth_service_required = cephx
auth_client_required = cephx
filestore_xattr_use_omap = true
public_network = <networkIP>
cluster_network = <networkIP>
osd_journal_size = 40000
mon_clock_drift_allowed = 1

keyring = <keyring>

keyring = <keyring>

keyring = <keyring>
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1 answer

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answered 2015-09-28 04:58:01 -0500

Tosugueur gravatar image

updated 2015-09-28 04:59:25 -0500

Hi. There are several points that I need to clarify:

  • Queues (like exchanges) are created by openstack services to consume messages from the exchanges (that are used to publish messages)
  • A Service do not publish messages directly into a queue (although it's possible but not recommended). It has to create an exchange where it can publish messages. Then, messages are routed based on the exchange type and, in to case of a topic exchange, the routing key.

So, instead of looking for the service that publishes messages, it would be better to look for the service that created these queues. In your case, it's probably Cinder. It tries to connect to all the rabbit nodes that you specified in the config file by creating queues in each rabbitmq server.

These queues may also be created in a previous installation but not deleted (which happens if a queue is set to Durable and rabbitmq is not reinstalled).

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During the OpenStack set up, the controller node executing Cinder changed several times without reinstalling rabbitmq. Thus these queues without consumers might have survived from the previous set up. Would a solution be in this case to simply delete these queues?

DanielJ gravatar imageDanielJ ( 2015-09-30 09:40:22 -0500 )edit

But why do queues like cinder-scheduler only occur once? How can I check whether a queue is set durable?

DanielJ gravatar imageDanielJ ( 2015-09-30 09:46:56 -0500 )edit

To ckeck the type of a queue you can use rabbitmq management plugin to do so: look for Features in the Queues panel and if it is set to D that means that the queue is Durable. There are many features: AD: auto-delete, D: durable, I: Internal, Combination of all of the previous features.

Tosugueur gravatar imageTosugueur ( 2015-11-18 04:22:53 -0500 )edit

I wouldn't recommend deleting a queue directly. Instead you can stop rabbitmq, reset it and re-start it. You can use these commands:
 $ sudo rabbitmqctl stop_app
 $ sudo rabbitmqctl reset
 $ sudo rabbitmqctl restart
Should be done before re-install of opens

Tosugueur gravatar imageTosugueur ( 2015-11-18 04:26:03 -0500 )edit

The parameters of these queues are: arguments: x-ha-policy: all auto-delete: true It seems, that they are not durable. The re-installation is no option since the cloud is already in use. My current workaround is a cron job that purges these queues every week.

DanielJ gravatar imageDanielJ ( 2015-11-19 02:02:02 -0500 )edit

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Asked: 2015-09-24 09:35:56 -0500

Seen: 941 times

Last updated: Sep 28 '15