Enabling SSL is highly recommended on live systems, as it protects sensitive information, like passwords, to be sent plain over the Internet, making it readable by eavesdroppers. If the Tomcat server is directly used from the Internet, to enable SSL / HTTPS you first have to enable (un-comment) the https connector in the file <tomcat_home>/conf/server.xml

<Connector port="443" maxHttpHeaderSize="8192"
    maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
    enableLookups="false" disableUploadTimeout="true"
    acceptCount="100" scheme="https" secure="true"
    clientAuth="false" sslProtocol="TLS" />

Generate a key with the keytool from Java:

$JAVA_HOME/bin/keytool -genkey -alias tomcat -keyalg RSA -keystore /path/to/my/keystore

After executing this command, you will first be prompted for the keystore password. Passwords are *case sensitive*. You will also need to specify the custom password in the server.xml configuration file, as described later. Next, you will be prompted for general information about this Certificate, such as company, contact name, and so on. This information will be displayed to users who attempt to access a secure page in your application, so make sure that the information provided here matches what they will expect. Finally, you will be prompted for the key password, which is the password specifically for this Certificate (as opposed to any other Certificates stored in the same keystore file). You MUST use the same password here as was used for the keystore password itself. (Currently, the keytool prompt will tell you that pressing the ENTER key does this for you automatically). If everything was successful, you now have a keystore file with a Certificate that can be used by your server.

The default memory heap size of Tomcat is very low. You can augment this in the following way:

Windows

In the bin directory of Tomcat create (if it doesn't exist) a file called setenv.bat, edit this file and add the following line:

set JAVA_OPTS=-Xms128m -Xmx512m -XX:MaxPermSize=128M

Linux

In the bin directory of Tomcat create (if it doesn't exist) a file called setenv.sh, edit this file and add the following line:

JAVA_OPTS="-Xms128m -Xmx512m -XX:MaxPermSize=128M"

Clustering is useful both for scaling (serving more requests) and for high availability (if a server crashes, the application continues to run). The main reason for configuring a cluster in Tomcat is to replicate HTTP sessions. Cyclos, however, doesn't use Tomcat sessions, but handles them internally. This way, there is no special Tomcat configuration to support a Cyclos cluster.

The Cyclos application, however, needs some small configurations to enable clustering. Cyclos uses Hazelcast to synchronize aspects (such as caches) between cluster servers. To enable clustering, find in cyclos.properties the line containing cyclos.clusterHandler, and set it to hazelcast.

Some extra configuration can be performed in the WEB-INF/classes/hazelcast.xml file. Basically, if the local network runs more than a single Cyclos instance, the group needs to be configured. Configure all files belonging to the same group with the same group name and password. It is also possible to change the default multicast to TCP/IP communication. Just comment the <multicast> tag and uncomment the <tcp-ip> tag, setting up the hosts / ports which will be part of the cluster. For a TCP/IP cluster, Hazelcast needs the host name / port of at least one node already in a cluster (it is not necessary to set all other nodes on each node).

To setup high-availability at database (Postgresql) level, please, refer to this document.