[Freeswitch-users] Getting 503 Service Unavailable while enable record_session

Hi Guys, I am using record_session applications on one of my live server, which have 100 concurrent calls are running. When i enable using dialplan then calls are dropping and getting most of call "503 Service Unavilable", so it means record_session generating load on freeswitch. I am using FreeSWITCH Version 1.4.21+git~20150901T202622Z~a223dd0236~64bit (git a223dd0 2015-09-01 20:26:22Z 64bit). Can any one please suggest me is it bug of Freeswitch ? -- Thanks, Bhavik Patel