Add dependency from simplemetrics.
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
</dependency>
+ <dependency>
+ <groupId>org.hdrhistogram</groupId>
+ <artifactId>HdrHistogram</artifactId>
+ </dependency>
<dependency>
<!-- TODO Vespa 8: stop providing org.json:json -->
<groupId>org.json</groupId>
