func monitorFileDescriptor(done <-chan struct{}) {
ticker := time.NewTicker(5 * time.Second)
defer ticker.Stop()
for {
used, err := runtime.FDUsage()
if err != nil {
plog.Errorf("cannot monitor file descriptor usage (%v)", err)
return
}
fileDescriptorUsed.Set(float64(used))
limit, err := runtime.FDLimit()
if err != nil {
plog.Errorf("cannot monitor file descriptor usage (%v)", err)
return
}
if used >= limit/5*4 {
plog.Warningf("80%% of the file descriptor limit is used [used = %d, limit = %d]", used, limit)
}
select {
case <-ticker.C:
case <-done:
return
}
}
}
func init() {
rand.Seed(time.Now().UnixNano())
expvar.Publish(
"file_descriptor_limit",
expvar.Func(
func() interface{} {
n, _ := runtime.FDLimit()
return n
},
),
)
}