increase number of consumer thread number in jmeter but got "Exception occurred while reading message from Kafka"

[mehrdad2000]

Hi
try this plugin https://github.com/rollno748/di-kafkameter in jmeter, but when i increased number of threads of consumer to 2 in jmeter got this error:

ERROR c.d.j.k.s.KafkaConsumerSampler: Exception occurred while reading message from Kafka java.util.ConcurrentModificationException: KafkaConsumer is not safe for multi-threaded access at org.apache.kafka.clients.consumer.KafkaConsumer.acquire(KafkaConsumer.java:2495) ~[kafka-clients-3.3.1.jar:?] at org.apache.kafka.clients.consumer.KafkaConsumer.acquireAndEnsureOpen(KafkaConsumer.java:2479) ~[kafka-clients-3.3.1.jar:?] at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:1227) ~[kafka-clients-3.3.1.jar:?] at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:1220) ~[kafka-clients-3.3.1.jar:?] at com.di.jmeter.kafka.sampler.KafkaConsumerSampler.getConsumerRecords(KafkaConsumerSampler.java:86) ~[di-kafkameter-1.3.jar:?] at com.di.jmeter.kafka.sampler.KafkaConsumerSampler.sample(KafkaConsumerSampler.java:68) [di-kafkameter-1.3.jar:?] at org.apache.jmeter.threads.JMeterThread.doSampling(JMeterThread.java:651) [ApacheJMeter_core.jar:5.6.2] at org.apache.jmeter.threads.JMeterThread.executeSamplePackage(JMeterThread.java:570) [ApacheJMeter_core.jar:5.6.2] at org.apache.jmeter.threads.JMeterThread.processSampler(JMeterThread.java:501) [ApacheJMeter_core.jar:5.6.2] at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:268) [ApacheJMeter_core.jar:5.6.2] at java.lang.Thread.run(Thread.java:829) [?:?]

FYI: if threads number of consumer equal to 1 it work correctly but only get 160 message per second.

Any idea?

[rollno748]

This is a known issue, multi threaded consumer on a single host is not recommended
Although, i can create a branch to try a approach to overcome this.