Exploring JMX with jmxterm

Check out the jmxterm repository / Download jmxterm from http://wiki.cyclopsgroup.org/jmxterm/

Launch:

java -jar ~/Downloads/jmxterm-1.0.0-uber.jar --url localhost:30002

You can pass the jmx host/port directly, or use the open command once jmxterm launches.

Once connected, use domains to list available domains

$>domains
#following domains are available
JMImplementation
com.sun.management
io.confluent.ksql.metrics
io.confluent.rest
java.lang
java.nio
java.util.logging
kafka.admin.client
kafka.consumer
kafka.producer
kafka.streams
[...]

Switch to a particular domain:

$>domain io.confluent.ksql.metrics
#domain is set to io.confluent.ksql.metrics

List the available MBeans in a the selected domain (you can also run this without choosing a domain first, to see every MBean, but it's a long list):

$>beans
#domain = io.confluent.ksql.metrics:
io.confluent.ksql.metrics:id=_confluent-ksql-confluent_rmoff_01query_CSAS_GOOD_RATINGS_0-11,key=ratings,type=consumer-metrics
io.confluent.ksql.metrics:id=_confluent-ksql-confluent_rmoff_01query_CSAS_GOOD_RATINGS_0-6904389f-5901-4b89-b331-53a6933d8ce0-StreamThread-4-producer,key=good_ratings,type=producer-metrics
io.confluent.ksql.metrics:type=kafka-metrics-count
io.confluent.ksql.metrics:type=ksql-engine-query-stats

Switch to a particular bean of interest:

$>bean io.confluent.ksql.metrics:type=ksql-engine-query-stats
#bean is set to io.confluent.ksql.metrics:type=ksql-engine-query-stats

List the available attributes:

$>info
#mbean = io.confluent.ksql.metrics:type=ksql-engine-query-stats
#class name = org.apache.kafka.common.metrics.JmxReporter$KafkaMbean
# attributes
%0   - bytes-consumed-total (double, r)
%1   - error-rate (double, r)
%2   - messages-consumed-avg (double, r)
%3   - messages-consumed-max (double, r)
%4   - messages-consumed-min (double, r)
%5   - messages-consumed-per-sec (double, r)
%6   - messages-consumed-total (double, r)
%7   - messages-produced-per-sec (double, r)
%8   - num-active-queries (double, r)
%9   - num-idle-queries (double, r)
%10  - num-persistent-queries (double, r)
#there's no operations
#there's no notifications
$>

Read the value of an attribute:

$>get messages-consumed-total
#mbean = io.confluent.ksql.metrics:type=ksql-engine-query-stats:
messages-consumed-total = 251329.0;

Note that jmxterm support tab-completion for all the commands, which makes it much easier to use.

Robin Moffatt

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Yorkshire, UK