To add an engine to a cluster, connect it to the shared database. Then, configure the
load balancer to send traffic to it.
Before you begin
- These steps are appropriate for engines that you install with IBM® UrbanCode™ Deploy and use to connect to non-OpenStack clouds. To set up clusters of OpenStack engines that you use
to connect to OpenStack clouds, see the OpenStack documentation.
- Set up a cluster of engines, including setting up a load balancer and shared database.
See Setting up clusters of engines.
- Each engine must run the same version of IBM UrbanCode Deploy.
About this task
You can add many engine nodes to the cluster as you need.
Procedure
- On the new node, install the engine as described in Installing engines. For the public address of the system, specify the IP address of the load balancer. For
the Keystone server, use the same Keystone server that you would use if you were
installing a single engine.
- After you install the engine, stop the Heat services.
- If you use an engine that is provided with IBM UrbanCode Deploy version
6.2.1.1 or later, configure the engine for the cluster by running a script. The script configures the Heat engine on this node to use the shared MariaDB database and
RabbitMQ service that you installed for the cluster of Heat engine servers. The script is provided
with the installation media for the Heat engine. You can run this script on only a Red Hat
Enterprise Linux (RHEL) version 7 server. Run the script by
using the following
command:
/extracted_location/ibm-ucd-patterns-install/engine-install/resources/tools/ha/add-engine2cluster.sh
-a allowed_uris
-d database_url
-k keystone_host
-r rabbitmq_host
In
this command, extracted_location is the location of the installation files, and
you must provide a value for each option.Option |
Description |
-a |
Set the authorized Keystone URIs. Separate each URI with a comma. For example,
http://first_keystone:5000/v3,http://second_keystone:5000/v2.0 |
-d |
Set the URL of the Heat engine MariaDB database. For example,
jdbc:mariadb://heat:heat@engine-database.example.com:3306/heat?charset=utf8 |
-k |
Set the Keystone host. For example, engine-database.example.com |
-r |
Set the RabbitMQ host. For example, engine-database.example.com |
- If you use an engine that is provided with versions of IBM UrbanCode Deploy before
6.2.1.1, configure the engine for the cluster by completing the following steps. The steps configure the Heat engine on this node to use the shared MySQL database and RabbitMQ
service that you installed for the cluster of Heat engine servers. These commands are for RHEL
version 6 servers.
- Stop the MySQL database and prevent it from starting at system startup by running the following
commands:
service mysqld stop
chkconfig mysqld off
The
engine does not require this service because it must use the shared engine database. If the cluster
node does not require MySQL for any other purpose, you can uninstall MySQL from the cluster
node.
- Open the /etc/heat/heat.conf file in a text editor.
- In the /etc/heat/heat.conf file, if you are connecting to a Keystone
engine other than the default Keystone engine for the cloud, find the
allowed_auth_uris property, and add the complete URL to the Keystone server to
the property value. For example, if the engine connects to clouds at
cloud1.example.com and cloud2.example.com, the property might look
like the following
example:
allowed_auth_uris=http://cloud1.example.com:5000/v2.0,http://cloud2.example.com:5002/v2
- Find the sql_connection property, and change it to the location of the
shared engine database. For example, if the shared engine database has the host name
engine-database.example.com, the property looks as
follows:
sql_connection=mysql://heat:heat@engine-database.example.com:3306/heat?charset=utf8
- Find the auth_host property, and update it to point to the load balancer
host name, as in the following example:
auth_host=ucd-patterns.example.com
- Find the rabbit_host property, and update it to point to the host name of
the shared engine database, as in the following example:
rabbit_host=engine-database.example.com
- Stop the RabbitMQ service:
service rabbitmq-server stop
- Prevent the RabbitMQ service from starting on system startup:
chkconfig rabbitmq-server off
- Open the /etc/keystone/keystone.conf file in a text editor.
- In the /etc/keystone/keystone.conf file, find the
connection parameter and update it to use shared engine database, as in the
following example:
connection=mysql://keystone:keystone@engine-database.example.com:3306/keystone?charset=utf8
- Start the Heat services by running the following commands:
cd /etc/init.d
for s in $(ls openstack*); do service $s start; done
for s in $(ls openstack*); do service $s status; done
- If you configured the engine by using a script, for only the first engine in the cluster,
complete the following steps:
- Synchronize the Keystone server and Heat engine databases. Run the following
commands:
keystone-manage db_sync
heat-manage db_sync
- To initialize the OpenStack endpoints for the engine cluster, run the
configure-os-services.sh script. Run the script by using the following
command:
/extracted_location/ibm-ucd-patterns-install/engine-install/resources/tools/ha/configure-os-services.sh
- Configure the load balancer to send traffic on the following ports to the new engine
node:
- 5000
- 35357
- 8004
- 8000
- 8003
For example, if you are using HAProxy, the configuration file might have code that
is similar to the following snippets. In this code example, it is assumed that the engine
nodes have these host names: engine1.example.com,
engine2.example.com, and
engine3.example.com.frontend keystone_api
bind *:5000
default_backend keystone_api_back
frontend keystone_admin
bind *:35357
default_backend keystone_admin_back
frontend heat_api
bind *:8004
default_backend heat_api_back
frontend heat_cfn
bind *:8000
default_backend heat_cfn_back
frontend heat_cloudwatch
bind *:8003
default_backend heat_cloudwatch_back
backend keystone_api_back
balance roundrobin
server enginenode1 engine1.example.com:5000 check
server enginenode2 engine2.example.com:5000 check
server enginenode3 engine3.example.com:5000 check
option httpchk
backend keystone_admin_back
balance roundrobin
server enginenode1 engine1.example.com:35357 check
server enginenode2 engine2.example.com:35357 check
server enginenode3 engine3.example.com:35357 check
option httpchk
backend heat_api_back
balance roundrobin
server enginenode1 engine1.example.com:8004 check
server enginenode2 engine2.example.com:8004 check
server enginenode3 engine3.example.com:8004 check
option httpchk
backend heat_cfn_back
balance roundrobin
server enginenode1 engine1.example.com:8000 check
server enginenode2 engine2.example.com:8000 check
server enginenode3 engine3.example.com:8000 check
option httpchk
backend heat_cloudwatch_back
balance roundrobin
server enginenode1 engine1.example.com:8003 check
server enginenode2 engine2.example.com:8003 check
server enginenode3 engine3.example.com:8003 check
option httpchk
- Restart the HAProxy service:
service haproxy restart
- On the new engine node, run the following commands to verify that the engine is
running:
source ˜/clientrc
heat stack-list
keystone endpoint-list
The
endpoints that the keystone endpoint-list command returns must refer to
the load balancer and not the engine node.
- Verify that the load balancer is sending traffic to the new node. For example, if HAProxy is installed on a system with the host
name ucd-patterns.example.com, you can go to the following URL to see the
status of the nodes:
http://ucd-patterns.example.com:1936/haproxy?stats
Results
The engine is part of the cluster.