How to read cassandra FQL logs in java? - cassandra

Question

I have a bunch of cassandra FQL logs with the "cq4" extension. I would like to read them in Java, is there a Java class that those log entries can be mapped into?
These are the logs I see.
I want to read this with this code:
import net.openhft.chronicle.Chronicle;
import net.openhft.chronicle.ChronicleQueueBuilder;
import net.openhft.chronicle.ExcerptTailer;
import java.io.IOException;
public class Main{
public static void main(String[] args) throws IOException {
Chronicle chronicle = ChronicleQueueBuilder.indexed("/Users/pavelorekhov/Desktop/fql_logs").build();
ExcerptTailer tailer = chronicle.createTailer();
while (tailer.nextIndex()) {
tailer.readInstance(/*class goes here*/)
}
}
}
I think from the code and screenshot you can understand what kind of class I need in order to read log entries into objects. Does that class exist in some cassandra maven dependency?

Answer 1

You are using Chronicle 3.x, which is very old.
I suggest using Chronicle 5.20.123, which is the version Cassandra uses.
I would assume Cassandra has it's own tool for reading the contents of these file however, you can dump the raw messages with net.openhft.chronicle.queue.main.DumpMain

Answer 2

I ended up cloning cassandra's github repo from here: https://github.com/apache/cassandra
In their code they have the FQLQueryIterator class which you can use to read logs, like so:
SingleChronicleQueue scq = SingleChronicleQueueBuilder.builder().path("/Users/pavelorekhov/Desktop/fql_logs").build();
ExcerptTailer excerptTailer = scq.createTailer();
FQLQueryIterator iterator = new FQLQueryIterator(excerptTailer, 1);
while (iterator.hasNext()) {
FQLQuery fqlQuery = iterator.next(); // object that holds the log entry
// do whatever you need to do with that log entry...
}