Configuring Watcher¶
This document is continually updated and reflects the latest available code of the Watcher service.
Service overview¶
The Watcher system is a collection of services that provides support to optimize your IAAS plateform. The Watcher service may, depending upon configuration, interact with several other OpenStack services. This includes:
- the OpenStack Identity service (keystone) for request authentication and to locate other OpenStack services
- the OpenStack Telemetry service (ceilometer) for consuming the resources metrics
- the OpenStack Compute service (nova) works with the Watcher service and acts as a user-facing API for instance migration.
The Watcher service includes the following components:
watcher-decision-engine
: runs audit on part of your IAAS and return an action plan in order to optimize resource placement.watcher-api
: A RESTful API that processes application requests by sending them to the watcher-decision-engine over RPC.watcher-applier
: applies the action plan.- python-watcherclient: A command-line interface (CLI) for interacting with the Watcher service.
- watcher-dashboard: An Horizon plugin for interacting with the Watcher service.
Additionally, the Bare Metal service has certain external dependencies, which are very similar to other OpenStack services:
- A database to store audit and action plan information and state. You can set the database back-end type and location.
- A queue. A central hub for passing messages, such as RabbitMQ.
Optionally, one may wish to utilize the following associated projects for additional functionality:
- watcher metering: an alternative to collect and push metrics to the Telemetry service.
Install and configure prerequisites¶
You can configure Watcher services to run on separate nodes or the same node. In this guide, the components run on one node, typically the Controller node.
This section shows you how to install and configure the services.
It assumes that the Identity, Image, Compute, and Networking services have already been set up.
Configure the Identity service for the Watcher service¶
Create the Watcher service user (eg
watcher
). The service uses this to authenticate with the Identity Service. Use theKEYSTONE_SERVICE_PROJECT_NAME
project (namedservice
by default in devstack) and give the user theadmin
role:$ keystone user-create --name=watcher --pass=WATCHER_PASSWORD \ --email=watcher@example.com \ --tenant=KEYSTONE_SERVICE_PROJECT_NAME $ keystone user-role-add --user=watcher \ --tenant=KEYSTONE_SERVICE_PROJECT_NAME --role=admin $ keystone user-role-add --user=watcher --tenant=admin --role=admin
or (by using python-openstackclient 1.8.0+)
$ openstack user create --password WATCHER_PASSWORD --enable \ --email watcher@example.com watcher \ --project=KEYSTONE_SERVICE_PROJECT_NAME $ openstack role add --project KEYSTONE_SERVICE_PROJECT_NAME \ --user watcher admin $ openstack role add --user watcher --project admin admin
You must register the Watcher Service with the Identity Service so that other OpenStack services can locate it. To register the service:
$ keystone service-create --name=watcher --type=infra-optim \ --description="Infrastructure Optimization service"
or (by using python-openstackclient 1.8.0+)
$ openstack service create --name watcher infra-optim \ --description="Infrastructure Optimization service"
Create the endpoints by replacing YOUR_REGION and
WATCHER_API_[PUBLIC|ADMIN|INTERNAL]_IP
with your region and your Watcher Service’s API node IP addresses (or FQDN):$ keystone endpoint-create \ --service-id=the_service_id_above \ --publicurl=http://WATCHER_API_PUBLIC_IP:9322 \ --internalurl=http://WATCHER_API_INTERNAL_IP:9322 \ --adminurl=http://WATCHER_API_ADMIN_IP:9322
or (by using python-openstackclient 1.8.0+)
$ openstack endpoint create --region YOUR_REGION watcher \ --publicurl http://WATCHER_API_PUBLIC_IP:9322 \ --internalurl http://WATCHER_API_INTERNAL_IP:9322 \ --adminurl http://WATCHER_API_ADMIN_IP:9322
Set up the database for Watcher¶
The Watcher service stores information in a database. This guide uses the MySQL database that is used by other OpenStack services.
In MySQL, create a
watcher
database that is accessible by thewatcher
user. Replace WATCHER_DBPASSWORD with the actual password:$ mysql -u root -p mysql> CREATE DATABASE watcher CHARACTER SET utf8; mysql> GRANT ALL PRIVILEGES ON watcher.* TO 'watcher'@'localhost' \ IDENTIFIED BY 'WATCHER_DBPASSWORD'; mysql> GRANT ALL PRIVILEGES ON watcher.* TO 'watcher'@'%' \ IDENTIFIED BY 'WATCHER_DBPASSWORD';
Configure the Watcher service¶
The Watcher service is configured via its configuration file. This file
is typically located at /etc/watcher/watcher.conf
.
You can easily generate and update a sample configuration file named watcher.conf.sample by using these following commands:
$ git clone git://git.openstack.org/openstack/watcher
$ cd watcher/
$ tox -econfig
$ vi etc/watcher/watcher.conf.sample
The configuration file is organized into the following sections:
[DEFAULT]
- General configuration[api]
- API server configuration[database]
- SQL driver configuration[keystone_authtoken]
- Keystone Authentication plugin configuration[watcher_clients_auth]
- Keystone auth configuration for clients[watcher_applier]
- Watcher Applier module configuration[watcher_decision_engine]
- Watcher Decision Engine module configuration[oslo_messaging_rabbit]
- Oslo Messaging RabbitMQ driver configuration[ceilometer_client]
- Ceilometer client configuration[cinder_client]
- Cinder client configuration[glance_client]
- Glance client configuration[nova_client]
- Nova client configuration[neutron_client]
- Neutron client configuration
The Watcher configuration file is expected to be named
watcher.conf
. When starting Watcher, you can specify a different
configuration file to use with --config-file
. If you do not specify a
configuration file, Watcher will look in the following directories for a
configuration file, in order:
~/.watcher/
~/
/etc/watcher/
/etc/
Although some configuration options are mentioned here, it is recommended that you review all the available options so that the watcher service is configured for your needs.
The Watcher Service stores information in a database. This guide uses the MySQL database that is used by other OpenStack services.
Configure the location of the database via the
connection
option. In the following, replace WATCHER_DBPASSWORD with the password of yourwatcher
user, and replace DB_IP with the IP address where the DB server is located:[database] ... # The SQLAlchemy connection string used to connect to the # database (string value) #connection=<None> connection = mysql://watcher:WATCHER_DBPASSWORD@DB_IP/watcher?charset=utf8
Configure the Watcher Service to use the RabbitMQ message broker by setting one or more of these options. Replace RABBIT_HOST with the IP address of the RabbitMQ server, RABBITMQ_USER and RABBITMQ_PASSWORD by the RabbitMQ server login credentials
[DEFAULT] # The messaging driver to use, defaults to rabbit. Other drivers # include qpid and zmq. (string value) #rpc_backend = rabbit # The default exchange under which topics are scoped. May be # overridden by an exchange name specified in the transport_url # option. (string value) control_exchange = watcher ... [oslo_messaging_rabbit] # The username used by the message broker (string value) rabbit_userid = RABBITMQ_USER # The password of user used by the message broker (string value) rabbit_password = RABBITMQ_PASSWORD # The host where the message brokeris installed (string value) rabbit_host = RABBIT_HOST # The port used bythe message broker (string value) #rabbit_port = 5672
Watcher API shall validate the token provided by every incoming request, via keystonemiddleware, which requires the Watcher service to be configured with the right credentials for the Identity service.
In the configuration section here below:
replace IDENTITY_IP with the IP of the Identity server
replace WATCHER_PASSWORD with the password you chose for the
watcher
userreplace KEYSTONE_SERVICE_PROJECT_NAME with the name of project created for OpenStack services (e.g.
service
)[keystone_authtoken] # Authentication type to load (unknown value) # Deprecated group/name - [DEFAULT]/auth_plugin #auth_type = <None> auth_type = password # Authentication URL (unknown value) #auth_url = <None> auth_url = http://IDENTITY_IP:35357 # Username (unknown value) # Deprecated group/name - [DEFAULT]/username #username = <None> username=watcher # User's password (unknown value) #password = <None> password = WATCHER_PASSWORD # Domain ID containing project (unknown value) #project_domain_id = <None> project_domain_id = default # User's domain id (unknown value) #user_domain_id = <None> user_domain_id = default # Project name to scope to (unknown value) # Deprecated group/name - [DEFAULT]/tenant-name #project_name = <None> project_name = KEYSTONE_SERVICE_PROJECT_NAME
Watcher’s decision engine and applier interact with other OpenStack projects through those projects’ clients. In order to instantiate these clients, Watcher needs to request a new session from the Identity service using the right credentials.
In the configuration section here below:
replace IDENTITY_IP with the IP of the Identity server
replace WATCHER_PASSWORD with the password you chose for the
watcher
userreplace KEYSTONE_SERVICE_PROJECT_NAME with the name of project created for OpenStack services (e.g.
service
)[watcher_clients_auth] # Authentication type to load (unknown value) # Deprecated group/name - [DEFAULT]/auth_plugin #auth_type = <None> auth_type = password # Authentication URL (unknown value) #auth_url = <None> auth_url = http://IDENTITY_IP:35357 # Username (unknown value) # Deprecated group/name - [DEFAULT]/username #username = <None> username=watcher # User's password (unknown value) #password = <None> password = WATCHER_PASSWORD # Domain ID containing project (unknown value) #project_domain_id = <None> project_domain_id = default # User's domain id (unknown value) #user_domain_id = <None> user_domain_id = default # Project name to scope to (unknown value) # Deprecated group/name - [DEFAULT]/tenant-name #project_name = <None> project_name = KEYSTONE_SERVICE_PROJECT_NAME
Configure the clients to use a specific version if desired. For example, to configure Watcher to use a Nova client with version 2.1, use:
[nova_client] # Version of Nova API to use in novaclient. (string value) #api_version = 2 api_version = 2.1
Create the Watcher Service database tables:
$ watcher-db-manage --config-file /etc/watcher/watcher.conf create_schema
Start the Watcher Service:
$ watcher-api && watcher-decision-engine && watcher-applier
Configure Nova compute¶
Please check your hypervisor configuration to correctly handle instance migration.
Configure Measurements¶
You can configure and install Ceilometer by following the documentation below :
- http://docs.openstack.org/developer/ceilometer
- http://docs.openstack.org/kilo/install-guide/install/apt/content/ceilometer-nova.html
The built-in strategy ‘basic_consolidation’ provided by watcher requires “compute.node.cpu.percent” and “cpu_util” measurements to be collected by Ceilometer. The measurements available depend on the hypervisors that OpenStack manages on the specific implementation. You can find the measurements available per hypervisor and OpenStack release on the OpenStack site. You can use ‘ceilometer meter-list’ to list the available meters.
For more information: http://docs.openstack.org/developer/ceilometer/measurements.html
Ceilometer is designed to collect measurements from OpenStack services and from other external components. If you would like to add new meters to the currently existing ones, you need to follow the documentation below:
The Ceilometer collector uses a pluggable storage system, meaning that you can pick any database system you prefer. The original implementation has been based on MongoDB but you can create your own storage driver using whatever technology you want. For more information : https://wiki.openstack.org/wiki/Gnocchi
Configure Nova Notifications¶
Watcher can consume notifications generated by the Nova services, in order to build or update, in real time, its cluster data model related to computing resources.
Nova publishes, by default, notifications on notifications
AMQP queue
(configurable) and versioned_notifications
AMQP queue (not
configurable). notifications
queue is mainly used by ceilometer, so we can
not use it. And some events, related to nova-compute service state, are only
sent into the versioned_notifications
queue.
By default, Watcher listens to AMQP queues named watcher_notifications
and versioned_notifications
. So you have to update the Nova
configuration file on controller and compute nodes, in order
to Watcher receives Nova notifications in watcher_notifications
as well.
In the file
/etc/nova/nova.conf
, update the section[oslo_messaging_notifications]
, by redefining the list of topics into which Nova services will publish events[oslo_messaging_notifications] driver = messaging topics = notifications,watcher_notificationsRestart the Nova services.
Workers¶
You can define a number of workers for the Decision Engine and the Applier.
If you want to create and run more audits simultaneously, you have to raise the number of workers used by the Decision Engine:
[watcher_decision_engine]
...
# The maximum number of threads that can be used to execute strategies
# (integer value)
#max_workers = 2
If you want to execute simultaneously more recommended action plans, you have to raise the number of workers used by the Applier:
[watcher_applier]
...
# Number of workers for applier, default value is 1. (integer value)
# Minimum value: 1
#workers = 1