apache+tomcat 연동 에러

아파치2.x와 tomcat5.5 mod_jk2를 사용하는데
아래의 에러가 발생하면서 tomcat연결이 안되는 현상이 가끔 발생하는데
해결 방법이있을까요?

[error] workerEnv.processCallbacks() Error reading reply
[error] ajp13.service() ajpGetReply recoverable error 120000
[error] channelApr.open() attempt to connect to 127.0.0.1:8009 (127.0.0.1) failed 111
[error] ajp13.connect() failed ajp13:localhost:8009
[error] ajp13.service() failed to connect endpoint errno=9 Bad file descriptor
[error] ajp13.service() Error forwarding ajp13:localhost:8009 1 1