Invert the flag & add fix doc

cmd/mtail/main.go

@@ -62,8 +62,8 @@ var (
 	logRuntimeErrors     = flag.Bool("vm_logs_runtime_errors", true, "Enables logging of runtime errors to the standard log.  Set to false to only have the errors printed to the HTTP console.")
 
 	// Ops flags.
-	pollInterval                = flag.Duration("poll_interval", 250*time.Millisecond, "Set the interval to poll all log files for list; must be positive, or zero to disable polling.  With polling mode, only the files found at mtail startup will be polled.")
-	pollLogInterval             = flag.Duration("poll_log_interval", 250*time.Millisecond, "Set the interval to poll all log files for data; must be positive, or zero to disable polling.  With polling mode, only the files found at mtail startup will be polled.")
+	pollInterval                = flag.Duration("poll_interval", 250*time.Millisecond, "Set the interval to poll each log file for data; must be positive, or zero to disable polling.  With polling mode, only the files found at mtail startup will be polled.")
+	pollLogInterval             = flag.Duration("poll_log_interval", 250*time.Millisecond, "Set the interval to find all matched log files for polling; must be positive, or zero to disable polling.  With polling mode, only the files found at mtail startup will be polled.")
 	expiredMetricGcTickInterval = flag.Duration("expired_metrics_gc_interval", time.Hour, "interval between expired metric garbage collection runs")
 	staleLogGcTickInterval      = flag.Duration("stale_log_gc_interval", time.Hour, "interval between stale log garbage collection runs")
 	metricPushInterval          = flag.Duration("metric_push_interval", time.Minute, "interval between metric pushes to passive collectors")
@@ -145,12 +145,12 @@ func main() {
 		trace.ApplyConfig(trace.Config{DefaultSampler: trace.ProbabilitySampler(1 / float64(*traceSamplePeriod))})
 	}
 	if *pollInterval == 0 {
-		glog.Infof("no poll interval specified; defaulting to 250ms poll")
+		glog.Infof("no poll log data interval specified; defaulting to 250ms poll")
 		*pollInterval = time.Millisecond * 250
 	}
 	if *pollLogInterval == 0 {
-		glog.Infof("no poll interval specified; defaulting to pollInterval")
-		*pollLogInterval = *pollInterval
+		glog.Infof("no poll log pattern interval specified; defaulting to 250ms poll")
+		*pollLogInterval = time.Millisecond * 250
 	}
 
 	ctx, cancel := context.WithCancel(context.Background())
@@ -183,8 +183,8 @@ func main() {
 		opts = append(opts, mtail.StaleLogGcWaker(staleLogGcWaker))
 	}
 	if *pollInterval > 0 {
-		logPatternPollWaker := waker.NewTimed(ctx, *pollInterval)
-		logStreamPollWaker := waker.NewTimed(ctx, *pollLogInterval)
+		logStreamPollWaker := waker.NewTimed(ctx, *pollInterval)
+		logPatternPollWaker := waker.NewTimed(ctx, *pollLogInterval)
 		opts = append(opts, mtail.LogPatternPollWaker(logPatternPollWaker), mtail.LogstreamPollWaker(logStreamPollWaker))
 	}
 	if *unixSocket == "" {

docs/Deploying.md

@@ -39,13 +39,13 @@ want to tail.  This includes named pipes.
 
 ### Polling the file system
 
-`mtail` polls every `--poll_interval`, or 250ms by default, the supplied `--logs` patterns for newly created or deleted log pathnames.
+`mtail` polls matched log files every `--poll_log_interval`, or 250ms by default, the supplied `--logs` patterns for newly created or deleted log pathnames.
 
-Known and active logs are read until EOF every 250ms by default.
+Known and active logs are read until EOF every `--poll_interval`, or 250ms by default.
 
 Example:
 ```
-mtail --progs /etc/mtail --logs /var/log/syslog --poll_interval 250ms
+mtail --progs /etc/mtail --logs /var/log/syslog --poll_interval 250ms --poll_log_interval 250ms
 ```