From 435fa22dd40b4860ec06d1074dc3c864f8968416 Mon Sep 17 00:00:00 2001
From: Marc Coury <gloriphobia@gmail.com>
Date: Fri, 7 May 2021 12:57:27 +0100
Subject: [PATCH] only retry sending a batch after an invalid sequence token
 once (#8)

* only retry sending a batch after an invalid sequence token once

* minor tweak

* Try editing github workflow yml

* try one more time to fix linter

* Update changelog
---
 .github/workflows/golangci-lint.yml |  4 ++--
 CHANGELOG.md                        |  6 ++++++
 cloudwatch_writer.go                | 15 ++++++++-------
 3 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/.github/workflows/golangci-lint.yml b/.github/workflows/golangci-lint.yml
index 94acc07..90026fc 100644
--- a/.github/workflows/golangci-lint.yml
+++ b/.github/workflows/golangci-lint.yml
@@ -22,6 +22,6 @@ jobs:
       - name: Report coverage
         run: bash <(curl -s https://codecov.io/bash) -t 50f54c52-6302-41a7-a8f7-9835c21b53f6
       - name: golangci-lint
-        uses: golangci/golangci-lint-action@v1
+        uses: golangci/golangci-lint-action@v2.3.0
         with:
-          version: v1.27
\ No newline at end of file
+          version: v1.35
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index c125806..4361a56 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,12 @@
 
 All notable changes to this project will be documented in this file. The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.2.4] - 2021-05-07
+
+### Fixed
+
+- Only allow one retry after an out of sequence token error.
+
 ## [0.2.3] - 2020-08-17
 
 ### Fixed
diff --git a/cloudwatch_writer.go b/cloudwatch_writer.go
index fa4a613..f23a3f6 100644
--- a/cloudwatch_writer.go
+++ b/cloudwatch_writer.go
@@ -163,7 +163,7 @@ func (c *CloudWatchWriter) queueMonitor() {
 
 	for {
 		if time.Now().After(nextSendTime) {
-			c.sendBatch(batch)
+			c.sendBatch(batch, 0)
 			batch = nil
 			batchSize = 0
 			nextSendTime.Add(c.getBatchInterval())
@@ -173,7 +173,7 @@ func (c *CloudWatchWriter) queueMonitor() {
 		if item == nil {
 			// Empty queue, means no logs to process
 			if c.isClosing() {
-				c.sendBatch(batch)
+				c.sendBatch(batch, 0)
 				// At this point we've processed all the logs and can safely
 				// close.
 				close(c.done)
@@ -193,7 +193,7 @@ func (c *CloudWatchWriter) queueMonitor() {
 		// Send the batch before adding the next message, if the message would
 		// push it over the 1MB limit on batch size.
 		if batchSize+messageSize > batchSizeLimit {
-			c.sendBatch(batch)
+			c.sendBatch(batch, 0)
 			batch = nil
 			batchSize = 0
 			nextSendTime = time.Now().Add(c.getBatchInterval())
@@ -203,7 +203,7 @@ func (c *CloudWatchWriter) queueMonitor() {
 		batchSize += messageSize
 
 		if len(batch) >= maxNumLogEvents {
-			c.sendBatch(batch)
+			c.sendBatch(batch, 0)
 			batch = nil
 			batchSize = 0
 			nextSendTime = time.Now().Add(c.getBatchInterval())
@@ -211,8 +211,9 @@ func (c *CloudWatchWriter) queueMonitor() {
 	}
 }
 
-func (c *CloudWatchWriter) sendBatch(batch []*cloudwatchlogs.InputLogEvent) {
-	if len(batch) == 0 {
+// Only allow 1 retry of an invalid sequence token.
+func (c *CloudWatchWriter) sendBatch(batch []*cloudwatchlogs.InputLogEvent, retryNum int) {
+	if retryNum > 1 || len(batch) == 0 {
 		return
 	}
 
@@ -227,7 +228,7 @@ func (c *CloudWatchWriter) sendBatch(batch []*cloudwatchlogs.InputLogEvent) {
 	if err != nil {
 		if invalidSequenceTokenErr, ok := err.(*cloudwatchlogs.InvalidSequenceTokenException); ok {
 			c.setNextSequenceToken(invalidSequenceTokenErr.ExpectedSequenceToken)
-			c.sendBatch(batch)
+			c.sendBatch(batch, retryNum+1)
 			return
 		}
 		c.setErr(err)