So, there's a difference between "how much RAM is in the box", and "how much RAM is allocated to the JVM".
The latter is where Azul Zing requires a lot of RAM to operate, as I understand it.
The recommended RAM for the JVM heap running Cassandra is 8GB, and 4GB isn't uncommon in the cloud. Netflix uses 12GB, and is contemplating going back to 8GB (they made that decision awhile ago, and things have changed since then).
I have boxes that run JVM heaps as low as 2GB just fine. It really just depends on how you're using it. (I've heard of people using 256MB heaps with Cassandra.)
The latter is where Azul Zing requires a lot of RAM to operate, as I understand it.
The recommended RAM for the JVM heap running Cassandra is 8GB, and 4GB isn't uncommon in the cloud. Netflix uses 12GB, and is contemplating going back to 8GB (they made that decision awhile ago, and things have changed since then).
I have boxes that run JVM heaps as low as 2GB just fine. It really just depends on how you're using it. (I've heard of people using 256MB heaps with Cassandra.)