Cassandra AWS System Memory Guidelines
System Memory Guidelines for Cassandra AWS
Basic guidelines for AWS Cassandra
Do not use less than 8GB of memory for the JVM. The more RAM the better. Use G1GC. SSTable are first stored in memory and then written to disk sequentially. The larger the SSTable the less scanning that needs to be done while reading and determining if a key is in an SSTable using a bloom filter. In the EC2 world this equates to an m4.xlarge (16GB of memory), and you need some memory for the OS, specifically the IO buffers. The i2.xlarge and d2.xlarge are the smallest in their family and exceed the min memory requirement (and then some).