From c529a081b15fc56e70f3259effbf0156c9a1bdd4 Mon Sep 17 00:00:00 2001
From: Antonio Lain <antonio.lain@temporal.io>
Date: Wed, 6 Mar 2024 13:09:47 -0800
Subject: [PATCH 1/2] Add eager workflow start sample

---
 .gitignore                     |  1 +
 README.md                      |  2 ++
 eager-workflow-start/README.md | 10 ++++++
 eager-workflow-start/main.go   | 59 ++++++++++++++++++++++++++++++++++
 4 files changed, 72 insertions(+)
 create mode 100644 eager-workflow-start/README.md
 create mode 100644 eager-workflow-start/main.go

diff --git a/.gitignore b/.gitignore
index fb369eea..ed980c9c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,3 +15,4 @@ vendor/
 # Executables produced by temporal-go-samples repo
 bin/
 .fossa.yml
+*~
diff --git a/README.md b/README.md
index 056bce9f..76a5ad96 100644
--- a/README.md
+++ b/README.md
@@ -140,6 +140,8 @@ Each sample demonstrates one feature of the SDK, together with tests.
 - [**Update**](./update): Demonstrates how to create a workflow that reacts
   to workflow update requests.
 
+- [**Eager Workflow Start**](./eager-workflow-start): Demonstrates how to start a workflow in eager mode, an experimental latency optimization.
+
 ### Dynamic Workflow logic examples
 
 These samples demonstrate some common control flow patterns using Temporal's Go SDK API.
diff --git a/eager-workflow-start/README.md b/eager-workflow-start/README.md
new file mode 100644
index 00000000..667671b2
--- /dev/null
+++ b/eager-workflow-start/README.md
@@ -0,0 +1,10 @@
+### Steps to run this sample:
+1) Run a [Temporal service](https://github.com/temporalio/samples-go/tree/main/#how-to-use) with eager workflow start enabled by a dynamic config value.
+```
+temporal server start-dev --dynamic-config-value system.enableEagerWorkflowStart=true
+```
+2) Run the following command to start the combined worker and example
+```
+go run eager-workflow-start/main.go
+```
+
diff --git a/eager-workflow-start/main.go b/eager-workflow-start/main.go
new file mode 100644
index 00000000..0d583e2c
--- /dev/null
+++ b/eager-workflow-start/main.go
@@ -0,0 +1,59 @@
+package main
+
+import (
+	"context"
+	"log"
+
+	"github.com/pborman/uuid"
+	"go.temporal.io/sdk/client"
+	"go.temporal.io/sdk/worker"
+
+	"github.com/temporalio/samples-go/helloworld"
+)
+
+const taskQueueName = "eager_wf_start"
+
+func main() {
+	// 1. Create the shared client.
+	c, err := client.Dial(client.Options{})
+	if err != nil {
+		log.Fatalln("Unable to create client", err)
+	}
+	defer c.Close()
+
+	// 2. Start the worker in a non-blocking manner before the workflow.
+	workerOptions := worker.Options{
+		OnFatalError: func(err error) { log.Fatalln("Worker error", err) },
+	}
+	w := worker.New(c, taskQueueName, workerOptions)
+	w.RegisterWorkflow(helloworld.Workflow)
+	w.RegisterActivity(helloworld.Activity)
+	err = w.Start()
+	if err != nil {
+		log.Fatalln("Unable to start worker", err)
+	}
+	defer w.Stop()
+
+	workflowOptions := client.StartWorkflowOptions{
+		ID:        "eager_wf" + uuid.New(),
+		TaskQueue: taskQueueName,
+
+		// 3. Set this flag to true to enable EWS.
+		EnableEagerStart: true,
+	}
+
+	// 4. Reuse the client connection.
+	we, err := c.ExecuteWorkflow(context.Background(), workflowOptions,
+		helloworld.Workflow, "Temporal")
+	if err != nil {
+		log.Fatalln("Unable to execute workflow", err)
+	}
+
+	// 5. Wait for workflow completion.
+	var result string
+	err = we.Get(context.Background(), &result)
+	if err != nil {
+		log.Fatalln("Unable to get workflow result", err)
+	}
+	log.Println("Workflow result:", result)
+}

From 22ecc06896de2cb5ae4b5651e830ef0b0c58d767 Mon Sep 17 00:00:00 2001
From: Antonio Lain <antonio.lain@temporal.io>
Date: Wed, 6 Mar 2024 21:20:13 -0800
Subject: [PATCH 2/2] Modify readme

---
 eager-workflow-start/README.md | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/eager-workflow-start/README.md b/eager-workflow-start/README.md
index 667671b2..0e35340a 100644
--- a/eager-workflow-start/README.md
+++ b/eager-workflow-start/README.md
@@ -1,4 +1,13 @@
+### Eager Workflow Start Sample
+
+Eager Workflow Start (EWS) is an experimental latency optimization with the goal of reducing the time it takes to start a workflow.
+
+When the starter and worker are collocated and aware of each other, they can interact while bypassing the server, saving a few time-intensive operations.
+
+Here we modify the `helloworld` sample, ensuring that starter and worker run in the same process, and share the client. Also, the request eager mode flag is set in the start workflow options.
+
 ### Steps to run this sample:
+
 1) Run a [Temporal service](https://github.com/temporalio/samples-go/tree/main/#how-to-use) with eager workflow start enabled by a dynamic config value.
 ```
 temporal server start-dev --dynamic-config-value system.enableEagerWorkflowStart=true