Code review comment: well then don't pass incomplete data. metrics are serialized one at a time, so you can just remember during serialization the last metrics that fit into the buffer, and once you go over the limit go back to that. You can also use other interesting heuristics like dropping histograms first (since they are significantly larger).

Code before review:
public void onReceive(Object message) {
try {
if (message instanceof AddMetric) {
AddMetric added = (AddMetric) message;
String metricName = added.metricName;
Metric metric = added.metric;
AbstractMetricGroup group = added.group;
QueryScopeInfo info = group.getQueryServiceMetricInfo(FILTER);
if (metric instanceof Counter) {
counters.put((Counter) metric, new Tuple2<>(info, FILTER.filterCharacters(metricName)));
} else if (metric instanceof Gauge) {
gauges.put((Gauge<?>) metric, new Tuple2<>(info, FILTER.filterCharacters(metricName)));
} else if (metric instanceof Histogram) {
histograms.put((Histogram) metric, new Tuple2<>(info, FILTER.filterCharacters(metricName)));
} else if (metric instanceof Meter) {
meters.put((Meter) metric, new Tuple2<>(info, FILTER.filterCharacters(metricName)));
}
} else if (message instanceof RemoveMetric) {
Metric metric = (((RemoveMetric) message).metric);
if (metric instanceof Counter) {
this.counters.remove(metric);
} else if (metric instanceof Gauge) {
this.gauges.remove(metric);
} else if (metric instanceof Histogram) {
this.histograms.remove(metric);
} else if (metric instanceof Meter) {
this.meters.remove(metric);
}
} else if (message instanceof CreateDump) {
MetricDumpSerialization.MetricSerializationResult dump = serializer.serialize(counters, gauges, histograms, meters);
int realMsgSize = dump.serializedMetrics.length;
if (realMsgSize > maximumFramesize) {
String overSizeErrorMsg = "The metric dump message size : " + realMsgSize
+ " exceeds the maximum akka framesize : " + maximumFramesize + ".";
LOG.error(overSizeErrorMsg);
getSender().tell(new Status.Failure(new IOException(overSizeErrorMsg)), getSelf());
} else {
getSender().tell(dump, getSelf());
}
} else {
LOG.warn("MetricQueryServiceActor received an invalid message. " + message.toString());
getSender().tell(new Status.Failure(new IOException("MetricQueryServiceActor received an invalid message. " + message.toString())), getSelf());
}
} catch (Exception e) {
LOG.warn("An exception occurred while processing a message.", e);
}
}

Line under review: getSender().tell(new Status.Failure(new IOException(overSizeErrorMsg)), getSelf());

Code after addressing the review:
public void onReceive(Object message) {
try {
if (message instanceof AddMetric) {
AddMetric added = (AddMetric) message;
String metricName = added.metricName;
Metric metric = added.metric;
AbstractMetricGroup group = added.group;
QueryScopeInfo info = group.getQueryServiceMetricInfo(FILTER);
if (metric instanceof Counter) {
counters.put((Counter) metric, new Tuple2<>(info, FILTER.filterCharacters(metricName)));
} else if (metric instanceof Gauge) {
gauges.put((Gauge<?>) metric, new Tuple2<>(info, FILTER.filterCharacters(metricName)));
} else if (metric instanceof Histogram) {
histograms.put((Histogram) metric, new Tuple2<>(info, FILTER.filterCharacters(metricName)));
} else if (metric instanceof Meter) {
meters.put((Meter) metric, new Tuple2<>(info, FILTER.filterCharacters(metricName)));
}
} else if (message instanceof RemoveMetric) {
Metric metric = (((RemoveMetric) message).metric);
if (metric instanceof Counter) {
this.counters.remove(metric);
} else if (metric instanceof Gauge) {
this.gauges.remove(metric);
} else if (metric instanceof Histogram) {
this.histograms.remove(metric);
} else if (metric instanceof Meter) {
this.meters.remove(metric);
}
} else if (message instanceof CreateDump) {
MetricDumpSerialization.MetricSerializationResult dump = serializer.serialize(counters, gauges, histograms, meters);
dump = enforceSizeLimit(dump);
getSender().tell(dump, getSelf());
} else {
LOG.warn("MetricQueryServiceActor received an invalid message. " + message.toString());
getSender().tell(new Status.Failure(new IOException("MetricQueryServiceActor received an invalid message. " + message.toString())), getSelf());
}
} catch (Exception e) {
LOG.warn("An exception occurred while processing a message.", e);
}
}