Difficulty: Easy
Estimated Time: 15 minutes

Cassandra 4.x full query logging enables you to get the exact CQL query strings used by your client applications. This information can be used for:

  • Analyzing poorly performing queries
  • Debugging queries that are producing incorrect results
  • Live traffic capture and replay
  • Troubleshooting/Debugging

In this scenario you will:

  • Enable and disable full query logging statically (in cassandra.yaml) and dynamically (using nodetool).
  • Learn features of the full query logging tool fqltool
  • Read and interpret full query logs

Full Query Logging

Step 1 of 5

Enable Full Query Logging via nodetool

In this step, you will enable full query logging via nodetool.

We've already started a single node Cassandra cluster for you in the background. When the command prompt appears in the terminal, the node is initialized and ready to go.

First, let's create a directory to store our full query log files:

mkdir /tmp/fqllogs

Now you can connect to the node using nodetool and enable full query logging, using the directory we just created as the path:

nodetool enablefullquerylog --path /tmp/fqllogs

To get a listing of the other options available on this command, execute the following:

nodetool help enablefullquerylog

Summary

In this step, you enabled full query logging dynamically on a running Cassandra node using nodetool and learned about the available options on the enablefullquerylog command.