1.服务出现FLAPPING状态时无法发出邮件报警信息
[1409537279] SERVICE ALERT: rs-07;Memory;CRITICAL;HARD;2;Connection refused by host
[1409537279] SERVICE FLAPPING ALERT: rs-07;Memory;STARTED; Service appears to have started flapping (28.2% change >= 20.0% threshold)

2.原因：flap_detection_enabled参数起作用，当服务在两种状态之间频繁切换时，为避免不停的发送报警，此参数用于抑制报警

define service{
name generic-service
active_checks_enabled 1
passive_checks_enabled 1
parallelize_check 1
obsess_over_service 1
check_freshness 0
notifications_enabled 1
event_handler_enabled 1
flap_detection_enabled 0 <--当服务在多个状态直接频繁切换时，抑制触发监控报警。使之不生效
failure_prediction_enabled 1
process_perf_data 1
retain_status_information 1
retain_nonstatus_information 1
is_volatile 0
check_period 24x7
max_check_attempts 3
normal_check_interval 10
retry_check_interval 2
contact_groups admins
notification_options w,u,c,r
notification_interval 60
notification_period 24x7
register 0
}