With stress tests completed, you might have identified the key areas for improvement. The broadest areas that you can categorize performance tuning into is the read and write performance area. Alternatively, there may be worries such as the I/O contention (compaction tuning) on servers. Apart from these, there may be several external factors to it, for example, slow disk, shared resources (such as shared CPU), and connectivity issues. We are not going to discuss external factors here. The assumption is that you will have sufficient resources allocated to the Cassandra servers. This section will discuss various tweaks to get Cassandra to start performing the best that it can within the given resources.