java.lang.ClassCastException with Cassandra version 4.1.2

[adithyagokhale]

Exporter reports too many of following exceptions with Cassandra version 4.1.2

Starting Cassandra exporter
JVM_OPTS:  -XX:MaxRAMFraction=2 -XX:+AlwaysPreTouch -Dorg.slf4j.simpleLogger.showDateTime=true -Dorg.slf4j.simpleLogger.dateTimeFormat="yyyy-MM-dd'T'HH:mm:ss" -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.port=5555 -Dcom.sun.management.jmxremote.local.only=false -Dnetworkaddress.cache.ttl=15
CASSANDRA_EXPORTER_CONFIG_host 127.0.0.1:7199
CASSANDRA_EXPORTER_CONFIG_listenPort 5556
Waiting for Cassandra JMX to start on  127.0.0.1:7199
Waiting for Cassandra JMX to start on  127.0.0.1:7199
Waiting for Cassandra JMX to start on  127.0.0.1:7199
Waiting for Cassandra JMX to start on  127.0.0.1:7199
Waiting for Cassandra JMX to start on  127.0.0.1:7199
Waiting for Cassandra JMX to start on  127.0.0.1:7199
Waiting for Cassandra JMX to start on  127.0.0.1:7199
OpenJDK 64-Bit Server VM warning: Option MaxRAMFraction was deprecated in version 10.0 and will likely be removed in a future release.
"2023-10-03T11:27:43" [main] INFO com.criteo.nosql.cassandra.exporter.Config - Loading yaml config from /tmp/config.yml
"2023-10-03T11:27:52" [main] INFO com.criteo.nosql.cassandra.exporter.JmxScraper - Scrap took 7180ms for the whole run
"2023-10-03T11:28:39" [main] INFO com.criteo.nosql.cassandra.exporter.JmxScraper - Scrap took 4279ms for the whole run
"2023-10-03T11:29:29" [main] INFO com.criteo.nosql.cassandra.exporter.JmxScraper - Scrap took 4396ms for the whole run
"2023-10-03T11:30:18" [main] INFO com.criteo.nosql.cassandra.exporter.JmxScraper - Scrap took 3602ms for the whole run
"2023-10-03T11:31:07" [main] INFO com.criteo.nosql.cassandra.exporter.JmxScraper - Scrap took 2299ms for the whole run
"2023-10-03T11:31:55" [main] ERROR com.criteo.nosql.cassandra.exporter.Main - Scrapper stopped due to uncaught exception
java.lang.ClassCastException: class java.lang.String cannot be cast to class java.lang.Number (java.lang.String and java.lang.Number are in module java.base of loader 'bootstrap')
        at com.criteo.nosql.cassandra.exporter.JmxScraper.updateMetric(JmxScraper.java:311)
        at com.criteo.nosql.cassandra.exporter.JmxScraper.lambda$run$12(JmxScraper.java:204)
        at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
        at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
        at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
        at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
        at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
        at java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948)
        at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
        at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
        at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
        at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
        at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
        at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
        at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:274)
        at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
        at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
        at java.base/java.util.HashMap$KeySpliterator.forEachRemaining(HashMap.java:1621)
        at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
        at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
        at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
        at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
        at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
        at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
        at com.criteo.nosql.cassandra.exporter.JmxScraper.run(JmxScraper.java:204)
        at com.criteo.nosql.cassandra.exporter.Main.start(Main.java:44)
        at com.criteo.nosql.cassandra.exporter.Main.main(Main.java:30)
"2023-10-03T11:31:57" [main] ERROR com.criteo.nosql.cassandra.exporter.Main - Scrapper stopped due to uncaught exception

Looks like it does not publish all the metrics due to this error. Can someone have a look at this ?

exporter uses SLF4J simple logger and there is no way to change the output log format. Is there a plan to support log4J ? This is needed to convert log messages into JSON for observability stack(EFK).