From 891a7a2a8dca0ef624ba769aac3c49211cc0a55e Mon Sep 17 00:00:00 2001
From: vlastahajek <vlastimil.hajek@bonitoo.io>
Date: Tue, 5 May 2020 13:44:36 +0200
Subject: [PATCH] docs: Doc and examples for WriteApi.Errors()

---
 CHANGELOG.md     |  2 +-
 README.md        | 52 ++++++++++++++++++++++++++++++++++++++++++++++++
 examples_test.go | 35 ++++++++++++++++++++++++++++++++
 3 files changed, 88 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7a378ec8..d1c01e48 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,9 +6,9 @@
 1. [#108](https://github.com/influxdata/influxdb-client-go/issues/108) Fix default retry interval doc
 1. [#110](https://github.com/influxdata/influxdb-client-go/issues/110) Allowing empty (nil) values
 
-
 ### Documentation
  - [#112](https://github.com/influxdata/influxdb-client-go/pull/112) Clarify how to use client with InfluxDB 1.8+
+ - [#115](https://github.com/influxdata/influxdb-client-go/pull/115) Doc and examples for reading write api errors 
 
 ## 1.1.0 [2020-04-24]
 ### Features
diff --git a/README.md b/README.md
index 9677fed0..2a10fd19 100644
--- a/README.md
+++ b/README.md
@@ -181,6 +181,58 @@ func main() {
     client.Close()
 }
 ```
+
+### Reading async errors
+[Error()](https://github.com/influxdata/influxdb-client-go/blob/master/write.go#L24) method returns a channel for reading errors which occurs during async writes. This channel is unbuffered and it 
+must be read asynchronously otherwise will block write procedure:
+
+```go
+package main
+
+import (
+    "fmt"
+    "math/rand"
+    "time"
+
+    "github.com/influxdata/influxdb-client-go"
+)
+
+func main() {
+    // Create client
+    client := influxdb2.NewClient("http://localhost:9999", "my-token")
+    // Get non-blocking write client
+    writeApi := client.WriteApi("my-org", "my-bucket")
+    // Get errors channel
+    errorsCh := writeApi.Errors()
+    // Create go proc for reading and logging errors
+    go func() {
+        for err := range errorsCh {
+            fmt.Printf("write error: %s\n", err.Error())
+        }
+    }()
+    // write some points
+    for i := 0; i < 100; i++ {
+        // create point
+        p := influxdb2.NewPointWithMeasurement("stat").
+            AddTag("id", fmt.Sprintf("rack_%v", i%10)).
+            AddTag("vendor", "AWS").
+            AddTag("hostname", fmt.Sprintf("host_%v", i%100)).
+            AddField("temperature", rand.Float64()*80.0).
+            AddField("disk_free", rand.Float64()*1000.0).
+            AddField("disk_total", (i/10+1)*1000000).
+            AddField("mem_total", (i/100+1)*10000000).
+            AddField("mem_free", rand.Uint64()).
+            SetTime(time.Now())
+        // write asynchronously
+        writeApi.WritePoint(p)
+    }
+    // Force all unwritten data to be sent
+    writeApi.Flush()
+    // Ensures background processes finishes
+    client.Close()
+}
+```
+
 ### Blocking write client 
 Blocking write client writes given point(s) synchronously. It doesn't have implicit batching. Batch is created from given set of points.
 
diff --git a/examples_test.go b/examples_test.go
index c6635059..2885249a 100644
--- a/examples_test.go
+++ b/examples_test.go
@@ -75,6 +75,41 @@ func ExampleWriteApi() {
 	client.Close()
 }
 
+func ExampleWriteApi_errors() {
+	// Create client
+	client := influxdb2.NewClient("http://localhost:9999", "my-token")
+	// Get non-blocking write client
+	writeApi := client.WriteApi("my-org", "my-bucket")
+	// Get errors channel
+	errorsCh := writeApi.Errors()
+	// Create go proc for reading and logging errors
+	go func() {
+		for err := range errorsCh {
+			fmt.Printf("write error: %s\n", err.Error())
+		}
+	}()
+	// write some points
+	for i := 0; i < 100; i++ {
+		// create point
+		p := influxdb2.NewPointWithMeasurement("stat").
+			AddTag("id", fmt.Sprintf("rack_%v", i%10)).
+			AddTag("vendor", "AWS").
+			AddTag("hostname", fmt.Sprintf("host_%v", i%100)).
+			AddField("temperature", rand.Float64()*80.0).
+			AddField("disk_free", rand.Float64()*1000.0).
+			AddField("disk_total", (i/10+1)*1000000).
+			AddField("mem_total", (i/100+1)*10000000).
+			AddField("mem_free", rand.Uint64()).
+			SetTime(time.Now())
+		// write asynchronously
+		writeApi.WritePoint(p)
+	}
+	// Force all unwritten data to be sent
+	writeApi.Flush()
+	// Ensures background processes finishes
+	client.Close()
+}
+
 func ExampleQueryApi_query() {
 	// Create client
 	client := influxdb2.NewClient("http://localhost:9999", "my-token")