func watchLogStats(stats *statsd.StatsdBuffer, logC chan dnsLogEntry, logs []chan dnsLogEntry) {
for {
stats.Gauge("incoming_log_depth", int64(len(logC)))
for i, logChan := range logs {
stats.Gauge(strconv.Itoa(i)+".log_depth", int64(len(logChan)))
}
time.Sleep(3)
}
}
//background task to clear out stale entries in the conntable
//one of these gets spun up for every packet handling thread
//takes a pointer to the contable to clean, the maximum age of an entry and how often to run GC
func cleanDnsCache(conntable *map[uint16]dnsMapEntry, maxAge time.Duration,
interval time.Duration, threadNum int, stats *statsd.StatsdBuffer) {
for {
time.Sleep(interval)
//max_age should be negative, e.g. -1m
cleanupCutoff := time.Now().Add(maxAge)
if stats != nil {
stats.Gauge(strconv.Itoa(threadNum)+".cache_size", int64(len(*conntable)))
}
for key, item := range *conntable {
if item.inserted.Before(cleanupCutoff) {
log.Debug("conntable GC(" + strconv.Itoa(threadNum) + "): cleanup query ID " + strconv.Itoa(int(key)))
delete(*conntable, key)
if stats != nil {
stats.Incr(strconv.Itoa(threadNum)+".cache_entries_dropped", 1)
}
}
}
}
}
