Workflows for orchestration in GCP - Step-by-Step Execution

Process Flow - Workflows for orchestration

Start Workflow

↓

Execute Step 1

↓

Check Step 1 Result

↓

Execute Step 2

↓

Check Step 2 Result

↓

Execute Step 3

↓

End Workflow

The workflow starts, executes steps in order, checks results, and handles errors before ending.

Execution Sample

GCP

start:
  call: http.get
  args:
    url: https://example.com/api
  result: response

next:
  switch:
    - condition: ${response.status_code == 200}
      next: success
    - condition: ${true}
      next: failure

This workflow calls an API, checks the response status, and branches based on success or failure.

Process Table

Step	Action	Input/Condition	Result	Next Step
1	Start Workflow	None	Workflow started	Execute Step 1
2	Execute Step 1	Call API https://example.com/api	Response status 200	Check Step 1 Result
3	Check Step 1 Result	response.status_code == 200	True	Execute Step 2
4	Execute Step 2	Process data from API	Data processed successfully	Check Step 2 Result
5	Check Step 2 Result	Processing success	True	Execute Step 3
6	Execute Step 3	Finalize workflow	Workflow finalized	End Workflow
7	End Workflow	None	Workflow completed successfully	None

💡 Workflow ends after all steps succeed without errors.

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
response.status_code	undefined	200	200	200	200
data.processed	false	false	true	true	true
workflow.state	started	step1_done	step2_done	step3_done	completed

Key Moments - 3 Insights

Why does the workflow check the response status after calling the API?

Because the workflow needs to decide the next step based on success or failure, as shown in execution_table row 3.

What happens if the response status is not 200?

The workflow would follow the failure branch to handle errors, but in this trace, it proceeds because the status is 200 (row 3).

How does the workflow know when to end?

It ends after the last step completes successfully, as shown in execution_table row 7.

Visual Quiz - 3 Questions

Look at the execution table, what is the response status after Step 1?

A 404

B 500

C 200

D undefined

💡 Hint

Check the 'Result' column in row 2 of the execution_table.

At which step does the workflow decide to proceed to Step 2?

A Step 1

B Step 3

C Step 5

D Step 4

💡 Hint

Look at the 'Next Step' column in row 3 of the execution_table.

If the API response status was 500, what would happen in the workflow?

A Handle Error after Step 1

B Proceed to Execute Step 2

C Skip Step 2 and Step 3

D End Workflow immediately

💡 Hint

Refer to the concept_flow where failure after Step 1 leads to error handling.

Concept Snapshot

Workflows run steps in order, checking results after each.
They branch on success or failure to handle errors.
Each step can call services or process data.
The workflow ends when all steps succeed or an error is handled.
Use conditions to control flow and ensure reliability.

Full Transcript

This visual execution shows how a Google Cloud Workflow runs steps one by one. It starts by calling an API, then checks if the response was successful. If yes, it processes data and finalizes the workflow. If any step fails, it handles errors accordingly. Variables like response status and workflow state update after each step. The workflow ends only after all steps succeed or an error is handled. This helps automate tasks reliably by controlling the flow based on results.