NotFoundException on MirrorSourceConnector

[fvaleri]

When testing MM2 integration with metrics reporter I'm getting NotFoundException on MirrorSourceConnector for some time after deploy. I wonder if we should handle this.

$ kubectl exec my-cluster-broker-0 -- curl -s http://$(kubectl get po $(kubectl get po | grep mm2 | awk '{print $1}') -o custom-columns=IP:status.podIP --no-headers):9404/metrics
An Exception occurred while scraping metrics: org.apache.kafka.connect.errors.NotFoundException: No status found for task my-cluster->my-cluster-tgt.MirrorSourceConnector-3
	at org.apache.kafka.connect.runtime.AbstractHerder.taskStatus(AbstractHerder.java:391)
	at org.apache.kafka.connect.runtime.Worker$ConnectorStatusMetricsGroup.lambda$null$2(Worker.java:2308)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:178)
	at java.base/java.util.concurrent.ConcurrentHashMap$ValueSpliterator.forEachRemaining(ConcurrentHashMap.java:3612)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
	at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921)
	at java.base/java.util.stream.ReduceOps$5.evaluateSequential(ReduceOps.java:258)
	at java.base/java.util.stream.ReduceOps$5.evaluateSequential(ReduceOps.java:248)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.base/java.util.stream.ReferencePipeline.count(ReferencePipeline.java:709)
	at org.apache.kafka.connect.runtime.Worker$ConnectorStatusMetricsGroup.lambda$taskStatusCounter$3(Worker.java:2309)
	at org.apache.kafka.connect.runtime.ConnectMetrics$MetricGroup.lambda$addValueMetric$0(ConnectMetrics.java:318)
	at org.apache.kafka.common.metrics.KafkaMetric.metricValue(KafkaMetric.java:81)
	at io.strimzi.kafka.metrics.kafka.KafkaCollector.collect(KafkaCollector.java:90)
	at io.strimzi.kafka.metrics.PrometheusCollector.collect(PrometheusCollector.java:61)
	at io.prometheus.metrics.model.registry.MultiCollector.collect(MultiCollector.java:26)
	at io.prometheus.metrics.model.registry.PrometheusRegistry.scrape(PrometheusRegistry.java:72)
	at io.prometheus.metrics.exporter.common.PrometheusScrapeHandler.scrape(PrometheusScrapeHandler.java:112)
	at io.prometheus.metrics.exporter.common.PrometheusScrapeHandler.handleRequest(PrometheusScrapeHandler.java:53)
	at io.prometheus.metrics.exporter.httpserver.MetricsHandler.handle(MetricsHandler.java:43)
	at jdk.httpserver/com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:95)
	at jdk.httpserver/sun.net.httpserver.AuthFilter.doFilter(AuthFilter.java:82)
	at jdk.httpserver/com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:98)
	at jdk.httpserver/sun.net.httpserver.ServerImpl$Exchange$LinkHandler.handle(ServerImpl.java:855)
	at jdk.httpserver/com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:95)
	at jdk.httpserver/sun.net.httpserver.ServerImpl$Exchange.run(ServerImpl.java:831)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base/java.lang.Thread.run(Thread.java:840)