1. Introduction
Nodetool is a command-line utility that is used to manage and monitor a Cassandra cluster. At the moment, it is included as part of the Cassandra distribution. It can be used to perform various tasks such as repairing and compressing data, flushing memtables, and taking and restoring snapshots. In this short article we'll list some basic Nodetool commands that are used with Cassandra.
2. Basic Nodetool commands
The most common Nodetool commands are:
- "nodetool status" - checking the status of the cluster
- "nodetool describekeyspaces" - used for displaying the available keyspaces and tables
- "nodetool info" -displaying information about the nodes in the cluster
- "nodetool repair" - used for repairing data on a node
- "nodetool flush" - flushing memtables to disk
- "nodetool snapshot" - taking a snapshot of the data on a node
- "nodetool restore" - restoring a snapshot to a node
Nodetool can be run on any node in the cluster and can be used to perform operations on a specific node or on the entire cluster. It is a useful tool for managing and maintaining a Cassandra cluster and is often used by database administrators to perform routine tasks and troubleshoot issues.
If you're running Cassandra cluster in Docker and you want to access Nodetool, you need to use docker exec like this:
docker exec -it cassandra1 nodetool status
This command will return the status of the nodes in the Cassandra cluster.
For the more detailed list of Nodetool commands, check the official Nodetool commands webpage.
Conclusion
Nodetool is one of the basic utilities of Cassandra distribution and not used with other database systems. If you are working with a different database system, you will need to use a different tool that is specific to that system. For example, MySQL has a command-line utility called mysqladmin that provides similar functionality, and MongoDB has a utility called mongodb that provides similar functionality.