Merge pull request #1 from bradchoate/master

An update to prevent an infinite loop

.gitignore

@@ -0,0 +1 @@
+/influxdb-relay

README.md

@@ -47,6 +47,7 @@ Usage of influxdb-relay:
   -listen-addr="127.0.0.1:4444": Local address for the UDP listener
   -max-line-length=256: Maximum line length for line protocol, in bytes
   -target-url="http://127.0.0.1:8086/write?db=example": URL where recieved data should be written
+  -attempt-limit=10: Maximum number of times to retry failed influxdb requests (0=infinite)
 ```
 
 License

main.go

@@ -19,6 +19,9 @@ var targetURL = flag.String(
 var listenAddrStr = flag.String(
 	"listen-addr", "127.0.0.1:4444", "Local address for the UDP listener",
 )
+var attemptLimit = flag.Int(
+	"attempt-limit", 10, "Maximum number of times to retry failed influxdb requests (0=infinite)",
+)
 
 func main() {
 	flag.Parse()
@@ -62,9 +65,9 @@ func main() {
 		SendBufferQueue: sendBufferQueue,
 	}
 	writer := &Writer{
-		SendBufferQueue:   sendBufferQueue,
-		TargetURL:         *targetURL,
-		RecvBufferQueue:   recvBufferQueue,
+		SendBufferQueue: sendBufferQueue,
+		TargetURL:       *targetURL,
+		RecvBufferQueue: recvBufferQueue,
 	}
 
 	go reader.Run()

writer.go

@@ -29,7 +29,17 @@ func (w *Writer) Run() {
 		msg := <-w.SendBufferQueue
 
 		// We'll keep trying to send this message until we succeed
+		// or get tired of trying
+		tries := 0
 		for {
+			tries += 1
+
+			// we tried, really hard, but let's be serious...
+			if tries == *attemptLimit {
+				log.Println("gave up writing to backend after", tries, "attempts")
+				break
+			}
+
 			contentReader := bytes.NewReader(msg.Content)
 
 			resp, err := client.Post(
@@ -40,10 +50,17 @@ func (w *Writer) Run() {
 				time.Sleep(2 * time.Second)
 				continue
 			}
+
 			// InfluxDB docs say that only 204 exactly is truly successful,
 			// and in fact 200 OK is not successful. Strange, but okay...
 			if resp.StatusCode != 204 {
 				log.Println("backend write returned", resp.Status)
+				if resp.StatusCode == 400 {
+					// invalid request; no amount of retries will
+					// reform malformed data
+					break
+				}
+
 				time.Sleep(2 * time.Second)
 				continue
 			}