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The Abiquo API can be balanced amongst several servers to spread load and increase service capacity. As you know, Abiquo provides an HTML5 client application that runs on your browser that interacts with the API to operate the cloud.
So, as As the UI is a regular HTML app, there may be several options to balance both the UI and the API.
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This document covers a setup sample for an Abiquo UI and Abiquo API balanced cluster.
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API plus UI cluster
In this setup, we are spreading the load amongst a cluster of nodes running both API and UI. Please note that any API clustered setup REQUIRES using zookeeper to workZookeeper.
For the sake of simplicity, we are using a two node setup, but this is easily scalable to several nodes and using Apache web server as a load balancer.
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Assume the following IP addressing for our cluster nodes.
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Start by installing backend severs using the Server profile of the Abiquo ISO installer. This profile will install API and UI webapps, as well as the zookeeper Zookeeper daemon needed for API to work in a clustered configuration.
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Once you have both servers with the Server profile installed, keep in mind that you need to keep the abiquo.properties file synchronized on every node in the API cluster.
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First, for the API to function as a clustered API, you need to setup Zookeeper. You may want to can run Zookeeper in on the LoadBalancer node or in on a separate box, depending in your needs and/or preferencesas preferred.
Zookeeper requires JVM to run, ensure that JVM (Oracle or OpenJDK) is installed.
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The zookeeper package is installed using the "Server" profile of the Abiquo installer ISO. If it is not installed, you can do so typingBut if you need to install it manually, use:
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# yum -y install zookeeper |
Then , you need to add the following line in the [server] section of the abiquo.properties file in on all Abiquo API server nodes:
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Replace <zookeeper_ip> to match your environment. Also , add or modify the abiquo.server.api.location property to match the load balancer URL for the API service (shown below):
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abiquo.server.api.location = https://abiquo.example.com/api |
You will need to edit file Edit the files /opt/abiquo/tomcat/conf/Catalina/localhost/api.xml and /opt/abiquo/tomcat/conf/Catalina/localhost/m.xml and set the values for the MySQL kinton database connection:. Change the url, username and password attributes to match your environment.
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<Resource name="jdbc/abiquoDB" auth="Container" type="javax.sql.DataSource" initialSize="10" suspectTimeout="60" timeBetweenEvictionRunsMillis="30000" minEvictableIdleTimeMillis="60000" maxActive="100" minIdle="10" maxIdle="50" maxWait="10000" removeAbandoned="true" removeAbandonedTimeout="60" logAbandoned="true" username="mysql_user" password="user_password" driverClassName="com.mysql.jdbc.Driver" url="jdbc:mysql://mysql.example.com:3306/kinton?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8"/> |
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UI configuration
In a clustered UI setup, you will need to configure the LB as the API endpoint for each UI node. Edit /var/www/html/ui/config/client-config.json file and set the same config.endpoint property for each UI node. For example:
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LoadBalancer Apache node configuration
You need to make sure To ensure that Apache's required modules are loaded. Be sure to include , add the following lines in to your Apache config file:
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LoadModule proxy_module modules/mod_proxy.so LoadModule proxy_balancer_module modules/mod_proxy_balancer.so LoadModule proxy_ftp_module modules/mod_proxy_ftp.so LoadModule proxy_http_module modules/mod_proxy_http.so LoadModule proxy_connect_module modules/mod_proxy_connect.so LoadModule proxy_ajp_module modules/mod_proxy_ajp.so |
In On the LoadBalancer node running Apache, create a new config file in /etc/httpd/conf.d/api-balancer.conf with the following contents:
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Restart or reload your Apache server to apply the new configuration.
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Note that this config enables Apache's balancer-manager to get information on the balancer cluster and perform basic operations on it. If you want to disable it, just comment or remove the <Location /> mark. |
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Abiquo API Tomcat configuration
Make sure Ensure the jvmRoute parameter is different in on each host as because this parameter will be used by Apache tomcat to route requests to each host.
To do thatthis, edit the /opt/abiquo/tomcat/conf/server.xml file inside in the tomcat directory and edit modify the following values:
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<Engine name="Catalina" defaultHost="localhost" jvmRoute="node1"> |
You need to import the LoadBalancer's Apache SSL certificate and CA into the Java truststore in order to enable the API to complete SSL SSL connections to API endpoints. In case If you are using a self-signed certificate for testing purposes, it will be enough importing the SSL certificate
This will suffice. This should be done in on every node running the API webapp:
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# echo -n | openssl s_client -connect abiquo.example.com:443 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > abiquo.example.com.cert # /usr/java/default/bin/keytool -import -file abiquo.example.com.cert -keystore /path/to/cacerts # /usr/java/default/bin/keytool -import -trustcacerts -file /path/to/ca/ca.pem -alias CA_ALIAS -keystore /path/to/cacerts |
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Restart tomcat after the change to apply the new configuration.
Now, access your balancer at https://abiquo.example.com/ui/ or https://abiquo.example.com/api/ . Requests between the two backend nodes will be adequately balanced.
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Check the API balancing with the following curl command:
Make sure the href links returned by the curl API call point to the correct location. Otherwise, check your configuration again. |
Other setups
Configuration The sample configuration described in this document covers the setup of a balanced Abiquo API and Abiquo UI cluster but you can change node distribution and LoadBalancer configuration to provide different setups depending on your requirements.
For For example, you may want to provide separate nodes for Abiquo UI and Abiquo API or maybe you may want just to cluster Abiquo UI and provide a single and shared Abiquo API node, etc.
Also, this sample uses Apache to provide the Load Balancing functionality but this can be achieved with other HA / Load Balancing solutions such as HAProxy or other vendor hardware / software tools.