When writing client-server java software, you might be surprised about the performance. More specifically, it could be that you deploy on some systems where things run fast, on some other systems horrible slow and on yet others there seem to be intermittent pauses.
This can happen when the server is being accessed by IP address. It seems that on some systems (even different systems with the same OS) the reverse DNS lookup is done more often than on others. SO basically, on each call to the server, the systems want to know the hostname for the server. Sometimes this is cached, sometimes a reverse DNS lookup is performed.
Fortunately, the solution is quite easy, if you don’t want to install and maintain a DNS server for your network, you just have to adjust the hosts file (/etc/networking hosts on linux, %windir%\system32\drivers\etc\hosts on windows) to include a name (any name) for the IP address of the server. Unfortunately though you need to do this on each client system.