Merge pull request #4389 from influxdb/hh_extra_segs

Don't add a new segment every HH purge check

CHANGELOG.md

@@ -18,6 +18,7 @@
 - [#4291](https://github.com/influxdb/influxdb/pull/4291): Added ALTER DATABASE RENAME. Thanks @linearb
 
 ### Bugfixes
+- [#4389](https://github.com/influxdb/influxdb/pull/4389): Don't add a new segment file on each hinted-handoff purge cycle.
 - [#4166](https://github.com/influxdb/influxdb/pull/4166): Fix parser error on invalid SHOW
 - [#3457](https://github.com/influxdb/influxdb/issues/3457): [0.9.3] cannot select field names with prefix + "." that match the measurement name
 - [#4225](https://github.com/influxdb/influxdb/pull/4225): Always display diags in name-sorted order

services/hh/queue.go

@@ -173,9 +173,8 @@ func (l *queue) PurgeOlderThan(when time.Time) error {
 	l.mu.Lock()
 	defer l.mu.Unlock()
 
-	// Add a new empty segment so old ones can be reclaimed
-	if _, err := l.addSegment(); err != nil {
-		return err
+	if len(l.segments) == 0 {
+		return nil
 	}
 
 	cutoff := when.Truncate(time.Second)
@@ -188,6 +187,16 @@ func (l *queue) PurgeOlderThan(when time.Time) error {
 		if mod.After(cutoff) || mod.Equal(cutoff) {
 			return nil
 		}
+
+		// If this is the last segment, first append a new one allowing
+		// trimming to proceed.
+		if len(l.segments) == 1 {
+			_, err := l.addSegment()
+			if err != nil {
+				return err
+			}
+		}
+
 		if err := l.trimHead(); err != nil {
 			return err
 		}