Requests take too long due to reverse DNS

[tomasol]

Hi. I am using jolokia 1.1.2 but I think this applies to latest HEAD as well:
When I issue curl requests from localhost, everything works fine.
When I connect from remote machine, each response has a noticable delay of ~5 seconds. I made a thread dump and it looks like address.getHostName() in JolokiaHttpHandler is taking most of that time - seems like a request for reverse DNS is made there. Is there a way to avoid this?

  java.lang.Thread.State: RUNNABLE 
at java.net.Inet6AddressImpl.getHostByAddr(Native Method) 
at java.net.InetAddress$1.getHostByAddr(InetAddress.java:898) 
at java.net.InetAddress.getHostFromNameService(InetAddress.java:583) 
at java.net.InetAddress.getHostName(InetAddress.java:525) 
at java.net.InetAddress.getHostName(InetAddress.java:497) 
at java.net.InetSocketAddress$InetSocketAddressHolder.getHostName(InetSocketAddress.java:82) 
at java.net.InetSocketAddress$InetSocketAddressHolder.access$600(InetSocketAddress.java:56) 
at java.net.InetSocketAddress.getHostName(InetSocketAddress.java:345) 
at org.jolokia.jvmagent.JolokiaHttpHandler.handle(JolokiaHttpHandler.java:119) 
at com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:77) 
at sun.net.httpserver.AuthFilter.doFilter(AuthFilter.java:83) 
at com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:80) 
at sun.net.httpserver.ServerImpl$Exchange$LinkHandler.handle(ServerImpl.java:668) 
at com.sun.net.httpserver.Filter$Chain.doFilter(Filter.java:77) 
at sun.net.httpserver.ServerImpl$Exchange.run(ServerImpl.java:640) 
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) 
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) 
at java.lang.Thread.run(Thread.java:722)

[rhuss]

I see you point but this is currently not possible.

The reason why a reverse DNS lookup happens is that the hostname can be configured in a policy file to restrict the access only from certain hosts. In the policy file you can set either the IP or the hostname.

In order to keep backwards compatibility the check against the hostname can not be removed by default but I could imagine to introduce a property noDnsReverseLookup to switch off this particular check (and anything which would do a reverse lookup, too.

[tomasol]

I agree with your proposal, thanks

[rhuss]

Fixed in 1.3.3