How much RAM does Cassandra need?

While Cassandra can be made to run on small servers for testing or development environments (including Raspberry Pis), a minimal production server requires at least 2 cores, and at least 8GB of RAM. Typical production servers have 8 or more cores and at least 32GB of RAM.

Is Apache Cassandra in-memory?

A fundamental limitation of Cassandra is that it is disk-based, not an in-memory database. This means that read performance is always capped by I/O specifications, ultimately restricting application performance and limiting the ability to attain an acceptable user experience.

Is Cassandra CPU intensive?

Cassandra is efficient for writes, but this is largely due to doing a structured merge sort during compaction, which is CPU intensive. Often the CPU becomes the limiting factor for writes.

How many Cassandra nodes do I need?

The minimal number should be 5, as a lower number (such as 3) will result in high stress on the machines during node failure (replication factor is 2 in this case, and each node will have to read 50\% of the data and write 50\% of data).

Does Cassandra need cache?

Key caching is enabled by default in Cassandra, and high levels of key caching are recommended for most scenarios. Cases for row caching are more specialized, but whenever it can coexist peacefully with other demands on memory resources, row caching provides the most dramatic gains in efficiency.

What is embedded Cassandra?

Basically, it starts Embedded Cassandra before test methods, has the ability to create structure and allows the developer to run CQL queries against production-like database without constantly starting the application, and without the need to have full API designed.

How do I create a quorum in Cassandra?

To set the consistency level for your current session, use the CONSISTENCY command from the cassandra shell (CQLSH). To see your current consistency level, just run CONSISTENCY; from the shell: ty@cqlsh> consistency; Current consistency level is ONE.

What is local quorum in Cassandra?

QUORUM – A majority (n/2 + 1) of the replicas must respond. ALL – All of the replicas must respond. LOCAL_QUORUM – A majority of the replicas in the local datacenter (whichever datacenter the coordinator is in) must respond. EACH_QUORUM – A majority of the replicas in each datacenter must respond.

How do I know my Cassandra heap size?

The easiest way to determine the optimum heap size for your environment is:

1. Set the maximum heap size in the cassandra-env.sh file to a high arbitrary value on a single node.
2. Enable GC logging.
3. Check the logs to view the heap used by that node and use that value for setting the heap size in the cluster:

How do I check my Cassandra heap?

You can use nodetool -u username -pw ********** info (if jmx is enabled ) command to get information about how much Heap and Off Heap Memory is used.

Is it possible to run Cassandra as a single node?

There is little point in running Cassandsra as a single node, although it is very helpful to do so to help you get up to speed on how it works. But to get the maximum benefit out of Cassandra, you would run it on multiple machines. Since it is a distributed database, Cassandra can (and usually does) have multiple nodes.

How do I create a three node Apache Cassandra cluster?

Let’s create a three node Apache Cassandra cluster. In order to create this cluster, you will need to have Docker and Docker Compose installed. Use Docker and Docker Compose installation documentation to get them both up and running on your machine.

Why choose Cassandra for your application?

Your application can write data to a Cassandra node on the U.S. west coast, and that data is automatically available in data centers at nodes in Asia and Europe. That has positive performance advantages – especially if you support a worldwide user base.

What is the architecture of Cassandra?

Cassandra also has a masterless architecture – any node in the database can provide the exact same functionality as any other node – contributing to Cassandra’s robustness and resilience. Multiple nodes can be organized logically into a cluster, or “ring”. You can also have multiple datacenters. Want more power? Add more nodes