Gateway service metric name contain hbase rowkey led to frequently full gc

Our Gateway Server frequently full gc in a few days. I dumped jvm heap and analyzed dump file with mat tool. I found some leak suspects about jmx metric, These leaks occurs in class org.apache.knox.gateway.services.metrics.impl.DefaultMetricsService. 

This is the analysis result generated by MAT

This is detail of problem Suspect 3

I found that many metrics which starting with service contain hbase rowkey by using visualVM tool. These metrics were generted when I used get api to query data from hbase. I think that name of service metric should not contain rowkey.

This is an example of metric name, the query command is 

curl -ik -u xx:xx   \
 -H "Accept: text/xml"  \
 -X GET \
 'https://localhost:8443/gateway/sandbox/hbase/demo/row[1-9]' 

The reason for this problem is that client and service metric both call the InstrUtils.getServiceResourcePath function to get resource path , but the parameters they use are different when build metric name. Suppose the request url is https://localhost:8443/gateway/sandbox/hbase/demo/row9. When building a client metric name, the parameter of the calling InstrUtils.getServiceResourcePath function is httpServletRequest.getPathInfo(), httpServletRequest.getPathInfo() value is /hbase/demo/row9. When building a service metric name, the parameter of the calling InstrUtils.getServiceResourcePath function is RequestLine.getUri(), RequestLine.getUri() value is /demo/row9. The purpose of InstrUtils.getServiceResourcePath is to obtain the first two elements of path. So service metric name contains rowkey.

I think that we should only obtain the first elements of path, when building service metric name.

The effect after applying the  pr791