NCP‐MCA_22 - itnett/FTD02H-N GitHub Wiki

Nutanix_Calm_Arrow_Scenarios_Mind_Map

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Based on the information I found, here is the clarification regarding the color of arrows in Nutanix Calm, specifically in relation to their creation, purpose, and potential testing on the NCP-MCA 6.5 exam.

Arrow Colors in Nutanix Calm Blueprints

Arrow Color Creation Purpose Example Use Case
Orange Automatically Generated by Calm Represents the order of execution of tasks within a profile action. Generated when a macro reference (e.g., @@{WebServer.address}@@) is used, indicating dependencies between tasks.
White Manually Drawn by User Represents logical dependencies between services. Used when you want to specify that one service should wait for another service to complete an action before starting.

Purpose and Usage of Arrows:

  1. Orange Arrows:

    • Creation: Automatically generated by Calm when it detects a dependency in your scripts or macros. For example, if the HAProxy service references the IP address of the WebServer (@@{WebServer.address}@@), Calm will automatically create an orange arrow from the WebServer service to the HAProxy service.
    • Purpose: These arrows define the order of execution of tasks in a blueprint. This ensures that tasks are executed in the correct sequence. The orange arrow tells Calm that one task cannot begin until another dependent task has finished.
    • Example Use Case: An orange arrow is created between "DB Start" and "App - Package Install," indicating that the application package installation cannot occur until the database is started and available.

  2. White Arrows:

    • Creation: Manually drawn by the user to define dependencies between services. These are added when more control is required over the task order than what the automatic system provides.
    • Purpose: White arrows indicate a dependency between services or tasks that Calm would not automatically infer from scripts or macros. It is used to create a specific order of operations.
    • Example Use Case: You manually draw a white arrow from the HAProxy service to the WebServer service to ensure that HAProxy does not start until the WebServer is up and running.

Potential Exam Testing on NCP-MCA 6.5

  1. Understanding Arrow Colors:

    • You might be asked to identify what different arrow colors represent in Calm blueprints, e.g., "What does an orange arrow signify?" or "How do white arrows differ from orange arrows in a Calm blueprint?"

  2. Creating Dependencies:

    • Questions may involve how to create or modify dependencies using arrows, such as "How would you ensure that a database service shuts down last in a multi-tier application?" This may involve drawing white arrows to manually set dependencies between services.

  3. Troubleshooting:

    • Scenarios where you might need to troubleshoot why a blueprint's tasks are not executing in the expected order. Understanding the difference between system-generated (orange) and user-defined (white) dependencies will be crucial.

By understanding these distinctions, you will better comprehend how Calm manages task orchestration and dependencies, which is a key skill tested in the NCP-MCA 6.5 exam. Make sure to practice scenarios where you use both types of arrows effectively to manage complex blueprints.

Here is a simplified mind map structure that focuses on explaining the difference between orange and white arrows in Nutanix Calm, aligned with the NCP-MCA 6.5 exam objectives:

Mind Map: Arrow Types and Their Significance in Nutanix Calm

1. Arrow Types

  • Orange Arrows
    • Description: Automatically Generated
    • Purpose: Represents the Order of Execution
    • Creation: Created by Macro References (e.g., Service.Property)
    • Example: Start the Web Server after the Database has initialized
  • White Arrows
    • Description: Manually Drawn
    • Purpose: Represents Logical Dependencies
    • Creation: Created by User-defined Dependencies between services
    • Example: Ensure the Database stops last to prevent downtime

2. Creation Methods

  • Orange Arrows: Automatic Generation
    • Trigger: Macro references in scripts (e.g., @@{DB.address}@@)
    • Scenario: Dependencies between tasks within services
  • White Arrows: Manual Drawing
    • Trigger: User creates a dependency manually
    • Scenario: Ensuring a specific service order not defined by macros

3. Purpose and Use Cases

  • Orange Arrows
    • Use: Automatically determine execution order
    • Exam Questions:
      • "What does an orange arrow indicate in a Calm blueprint?"
      • "How are orange arrows created in Nutanix Calm?"
  • White Arrows
    • Use: Provide manual control over task execution order
    • Exam Questions:
      • "How do you create a white dependency arrow in Calm?"
      • "What is the purpose of a white arrow in Calm?"

4. Common Scenarios for Testing

  • Scenario 1: Understanding Arrow Meanings
    • Question: "What is the difference between orange and white arrows?"
    • Key Concept: Orange = Automatic; White = Manual
  • Scenario 2: Arrow Troubleshooting
    • Question: "Task order is incorrect; no arrows are present. What might be missing?"
    • Key Concept: Missing dependencies; add white arrows
  • Scenario 3: Dependency Management
    • Question: "How do you ensure the Load Balancer starts after the Web Server?"
    • Key Concept: Use white arrows to define service order
  • Scenario 4: Macro Dependency Identification
    • Question: "Which tasks cause orange arrows in a blueprint?"
    • Key Concept: Macros in scripts trigger orange arrows

5. Exam Tips and Strategies

  • Recognize Arrow Colors:
    • Orange = Automatic (execution order defined by system)
    • White = Manual (user-defined logical dependencies)
  • Understand Creation and Purpose:
    • Know the "how" and "why" for each arrow type
  • Troubleshooting Preparation:
    • Practice scenarios with missing or incorrect dependencies
  • Focus on Practical Application:
    • Use hands-on labs or practice tests to understand daily usage

How This May Be Tested in NCP-MCA 6.5:

  1. Understanding Arrow Colors:
    • You may be asked to distinguish between the two types of arrows in a blueprint and explain what they signify.
  2. Troubleshooting Scenarios:
    • You may be given a scenario where tasks are not executing in the desired order and asked to identify which type of arrow should be used to correct the issue.
  3. Arrow Creation Methods:
    • Questions could focus on how arrows are created automatically (via macros) or manually (via user action) in a Calm blueprint.
  4. Practical Application:
    • Expect questions that test your ability to manage dependencies and execution order in real-world blueprint configurations.

By familiarizing yourself with these concepts, you’ll be well-prepared to handle any questions related to arrows in Nutanix Calm blueprints during your NCP-MCA 6.5 exam.

Here's a table summarizing the most likely causes of failures in Nutanix Calm blueprints when there are white arrows (manual dependencies) versus orange arrows (automatic dependencies):

Arrow Type Failure Cause Description Example Scenario
Orange Arrows Incorrect Macro Usage If a macro reference is used incorrectly in scripts, Calm will not be able to generate the orange arrow for the correct order of execution. A macro like @@{DB.address}@@ is incorrectly formatted or placed in a script, causing the system to fail in establishing the order of execution between DB and App tasks.
Missing Macro Reference If a script that should contain a macro reference is missing it, Calm cannot automatically generate the correct execution order, leading to failure or unexpected behavior. The Package Install script in HAProxy lacks the @@{WebServer.address}@@ reference, so Calm does not know that WebServer must start before HAProxy.
Circular Dependencies via Macros If there are conflicting macro references that imply circular dependencies, Calm will not be able to determine a valid execution order and will raise an error. DB references App and vice versa through macros, causing a loop that prevents any task from starting.
Service Not Ready When a macro reference points to a property of a service that isn't fully initialized or operational, the task will fail because it relies on a non-existent or unready resource. The App service task references DB.address, but DB service is not yet initialized, leading to failure in retrieving the IP address.
White Arrows Incorrect Manual Dependencies If white arrows are drawn incorrectly, such that they do not reflect the logical dependency or task order, tasks may execute out of sequence and cause a failure. A white arrow indicates WebServer depends on HAProxy, but in reality, HAProxy should start after WebServer due to a missing IP dependency.
Missing Manual Dependencies If the user fails to draw necessary white arrows for critical tasks, services may start or stop in the wrong order, causing errors or unexpected downtime. A blueprint lacks a white arrow from App to DB, resulting in App starting before the database is ready, causing connection failures.
Circular Dependencies via White Arrows Manually drawn white arrows that form a circular dependency will cause Calm to recognize a loop, preventing any tasks from executing. DB has a white arrow pointing to App, and App has a white arrow pointing back to DB, creating an unresolvable loop in execution order.
Service Interruption or Downtime If white arrows are not properly defined, services might shut down or restart in an order that leads to application downtime or partial failure. WebServer stops before DB due to missing dependencies, leading to application errors while shutting down.
User Error in Defining Dependencies Incorrect use of white arrows to define non-essential dependencies can lead to unnecessary delays or task failures when they are executed. An unnecessary white arrow is drawn from Monitoring Service to Database Service, causing the monitoring to wait until the database is fully started, creating delays.
Misinterpretation of Dependency Order Users may misinterpret the logical order required for operations, creating white arrows that contradict the intended flow, causing failures or delays in the deployment. A dependency is defined such that the Backup task runs before the Data Sync task, when it should occur after the synchronization is complete.

Key Points:

  • Orange Arrows are automatically generated by macro references in scripts and define the execution order based on these dependencies.
  • White Arrows are manually drawn by users to represent logical dependencies between tasks or services.

Likely Exam Focus Areas:

  1. Identify Failure Causes:
    • Recognize scenarios where missing or incorrect macros lead to failures with orange arrows.
    • Understand issues that arise from incorrectly drawn white arrows or missing manual dependencies.
  2. Troubleshoot Task Order Failures:
    • Determine the impact of missing dependencies or circular dependencies.
    • Explain why certain tasks failed due to dependency misconfiguration (either by orange or white arrows).

Here’s an explanation of how white and orange arrows impact and appear in Calm blueprints for different components, such as a multi-VM blueprint, database service, web server service, load balancing service, adding dependencies, Day 2 operations, and configuring and executing runbooks:

1. Impact of White and Orange Arrows in Calm Blueprints

White Arrows: Manual Dependencies

  • Purpose: White arrows in Calm blueprints are manually created by users to define logical dependencies between tasks or services.
  • Impact: These arrows ensure that specific services or tasks occur in a certain order to maintain the proper functioning of the application. For example, they can prevent a web server from starting before the database is ready.
  • How to Create: In the Calm blueprint interface, you can manually draw white arrows by selecting a task or service, clicking the "Create Dependency" icon, and then dragging to the dependent task or service.

Orange Arrows: Automatic Dependencies

  • Purpose: Orange arrows are automatically generated by Calm when it detects dependencies in the scripts, usually through the use of macros (like @@{Service.Property}@@).
  • Impact: These arrows show the execution order of tasks based on inherent dependencies between services. For instance, if the web server needs the database’s IP address to function, an orange arrow will show that the database must be initialized before the web server starts.
  • How to Create: Orange arrows are created automatically by Calm when it detects a macro reference in a task script. Users cannot directly create or modify these arrows.

2. Marketplace Blueprints and Multi-VM Blueprints

  • Marketplace Blueprints: These are pre-built blueprints available in the Calm Marketplace for common applications or services.

    • White Arrows: When customizing a Marketplace blueprint, you might need to manually draw white arrows to adjust the dependency order based on your specific environment or requirements.
    • Orange Arrows: Marketplace blueprints may already contain orange arrows if they use macro references to define dependencies automatically.

  • Multi-VM Blueprints: Blueprints designed to deploy multiple VMs (Virtual Machines) for different components of an application.

    • White Arrows: Ensure that VM dependencies (e.g., database VM before web server VM) are correctly managed to prevent application failures.
    • Orange Arrows: Automatically indicate the sequence in which tasks should run (e.g., set up the network interface on one VM before deploying another dependent VM).

3. Database Service, Web Server Service, Load Balancing Service

  • Database Service (DB):

    • White Arrows: You may manually set dependencies to ensure the database is up and running before any other dependent services (like a web server or application service).
    • Orange Arrows: Automatically created when the web server or other services reference the database's properties (like @@{DB.address}@@) in their scripts, showing that the DB service must start first.

  • Web Server Service:

    • White Arrows: Define the order in which the web server should start or stop in relation to other services (e.g., load balancer starts after the web server).
    • Orange Arrows: Automatically show the sequence if there are any script references to other services (e.g., @@{DB.address}@@ in the web server's configuration script).

  • Load Balancing Service:

    • White Arrows: Used to control the startup or shutdown order of the load balancer concerning other services (e.g., start load balancer after the web server is online).
    • Orange Arrows: Will be created if the load balancer configuration references properties of the web server or other services.

4. Adding Dependencies

  • Adding White Dependencies:

    • Use white arrows to manually set dependencies between different components or tasks to control the sequence of operations. This is crucial when you have tasks that depend on specific conditions (e.g., the database must be running before the web server starts).

  • Creating Dependencies Using Orange Arrows:

    • Orange arrows are created automatically when there are macro references in scripts (e.g., @@{WebServer.address}@@ in the load balancer's script), ensuring that dependent tasks execute in the correct order based on those references.

5. Day 2 Operations

  • What are Day 2 Operations?

    • Day 2 operations refer to tasks or actions performed on an application after it has been initially deployed (i.e., ongoing management tasks like scaling, upgrades, backups, etc.). Examples include:
      • Scaling In/Out: Increasing or decreasing the number of instances of a service.
      • Upgrading Software: Applying patches or new versions.
      • Backup and Restore: Taking backups and restoring applications/services.

  • Use of Arrows in Day 2 Operations:

    • White Arrows: Used to manually define dependencies for Day 2 actions to ensure operations are executed correctly (e.g., backup the database before upgrading).
    • Orange Arrows: Automatically generated when tasks reference dependencies through macros (e.g., ensuring a service is stopped before applying an upgrade).

6. Configuring and Executing Runbooks

  • What are Runbooks?

    • Runbooks are sets of automated tasks executed to perform repetitive or common tasks like backups, updates, scaling, etc.

  • Arrows in Runbooks:

    • White Arrows: Manually create dependencies between runbook tasks to ensure they execute in the correct order.
    • Orange Arrows: Automatically appear if there are macro dependencies within the scripts (e.g., task B depends on the output of task A).

Exam Focus Areas for NCP-MCA 6.5

  • Recognizing Arrow Types:
    • Understand the difference between white and orange arrows, their purpose, and how they are created (manually vs. automatically).
  • Troubleshooting Task Failures:
    • Given a failure scenario, determine if the issue is due to missing dependencies (missing white arrows) or incorrect macro references (missing orange arrows).
  • Designing Blueprints:
    • Know how to create blueprints that properly use both types of arrows to ensure a smooth deployment and operation of services.
  • Understanding Day 2 Operations:
    • Be familiar with how dependencies affect Day 2 operations, including the addition or removal of services, scaling, and updates.

Summary

  • Orange Arrows: Automatically generated, represent execution order, based on macro references.
  • White Arrows: Manually drawn, represent logical dependencies, defined by user requirements.
  • Key Focus: Know how to identify, use, and troubleshoot both types of arrows to ensure successful blueprint deployment and management.

To provide a comprehensive coverage of the troubleshooting topics for blueprints in the NCP-MCA 6.5 exam, focusing on all types of arrows (white and orange), dependencies, and relevant scenarios, we will explore various problem scenarios, potential issues, and solutions that could be tested in the exam.

Comprehensive Troubleshooting Guide for Blueprints in NCP-MCA 6.5

1. Understanding Arrow Types and Their Significance

  • Orange Arrows
    • Definition: Automatically generated by Nutanix Calm.
    • Purpose: Represents the order of execution of tasks, based on dependencies defined by macros.
    • Creation Method: Automatically created when a script contains a macro reference (e.g., @@{Service.Property}@@).
    • Common Issues: Incorrect or missing macro references, circular dependencies caused by conflicting macros, tasks executing in the wrong order.
  • White Arrows
    • Definition: Manually drawn by the user to define logical dependencies.
    • Purpose: Used to manually control the order of execution between tasks or services.
    • Creation Method: Manually drawn in the Calm blueprint editor by clicking the "Create Dependency" icon.
    • Common Issues: Incorrect manual dependencies, missing dependencies causing services to execute in the wrong order, circular dependencies due to improper manual configurations.

2. Common Blueprint Scenarios and Troubleshooting Tips

Scenario 1: Marketplace Blueprints and Multi-VM Blueprints
  • Common Issues:
    • Orange Arrows:
      • Issue: Missing orange arrows between tasks or services.
      • Cause: Missing macro references in the blueprint scripts.
      • Solution: Ensure that all necessary macros are present in the scripts. For example, if a web server requires the database's IP address, include @@{DB.address}@@ in the web server's script.
    • White Arrows:
      • Issue: Incorrect order of service execution due to missing or improperly placed white arrows.
      • Cause: Manual dependencies were not defined correctly between services (e.g., web server starts before the database is ready).
      • Solution: Manually draw white arrows to ensure the correct service order. For example, draw a white arrow from the database service to the web server service.
Scenario 2: Database Service, Web Server Service, Load Balancing Service
  • Common Issues:
    • Orange Arrows:
      • Issue: Database service tasks are not completing before the web server tasks start.
      • Cause: Missing macro references or incorrect usage in the web server’s scripts (e.g., missing @@{DB.address}@@).
      • Solution: Add the correct macro references to the web server scripts to create the required orange arrow for execution order.
    • White Arrows:
      • Issue: Load balancer starts before the web server, causing routing errors.
      • Cause: Manual dependencies were not correctly defined.
      • Solution: Add a white arrow from the web server service to the load balancer service to ensure the web server starts first.
Scenario 3: Adding Dependencies
  • Common Issues:
    • Orange Arrows:
      • Issue: No orange arrows appear even when dependencies are required.
      • Cause: Scripts lack the necessary macro references to create dependencies.
      • Solution: Check and add appropriate macros to the scripts to establish dependencies (e.g., @@{ServiceA.address}@@ in Service B).
    • White Arrows:
      • Issue: Misconfigured dependencies leading to incorrect service startup order.
      • Cause: White arrows were incorrectly drawn or missed.
      • Solution: Review and adjust the manually drawn white arrows to ensure the correct dependency order.
Scenario 4: Day 2 Operations
  • Common Issues:
    • Orange Arrows:
      • Issue: Day 2 operation tasks fail to execute in the correct order.
      • Cause: Dependencies defined by macros are missing or incorrectly implemented.
      • Solution: Ensure that macros are correctly implemented to create dependencies between tasks (e.g., scaling or upgrading tasks).
    • White Arrows:
      • Issue: Backup operation runs after an upgrade, leading to inconsistencies.
      • Cause: Incorrect manual dependency setup (white arrows).
      • Solution: Manually create white arrows to ensure backup tasks run before upgrade tasks.
Scenario 5: Configuring and Executing Runbooks
  • Common Issues:
    • Orange Arrows:
      • Issue: Runbook tasks fail to execute in the expected order.
      • Cause: Missing macro references or errors in the scripts.
      • Solution: Review runbook scripts to ensure correct macros are used for dependencies.
    • White Arrows:
      • Issue: Runbook tasks are executed out of sequence.
      • Cause: Missing or incorrect manual dependencies (white arrows).
      • Solution: Add white arrows to enforce the correct task execution order in the runbook.

3. Specific Troubleshooting Scenarios with Potential Exam Questions

Scenario Potential Issue Solution Exam Question Example
Orange Arrow Missing Macro references missing in the blueprint script. Add necessary macros (e.g., @@{DB.address}@@) to establish automatic dependencies. "Why is the orange arrow not appearing between DB and Web Server services?"
White Arrow Misconfiguration Manual dependencies are incorrectly drawn or missing, causing the wrong task order. Redraw the white arrows to correctly define dependencies between services. "How would you fix the issue where the web server starts before the database is ready?"
Circular Dependencies with Orange Arrows Conflicting macro references create a circular dependency loop. Remove or correct conflicting macros to eliminate the circular dependency. "What is causing a circular dependency error between DB and App services?"
Incorrect Day 2 Operation Sequence Dependencies not properly defined, leading to Day 2 tasks executing out of order (e.g., backup after upgrade). Use white arrows to manually define the correct order for Day 2 operations. "How can you ensure that backup operations always run before upgrades in a Calm blueprint?"
Runbook Task Order Failure Tasks in a runbook are executing incorrectly due to missing dependencies. Add white arrows to define the correct task sequence in the runbook. "What steps should you take to ensure that tasks in a runbook execute in the desired order?"
Execution Order Errors in Marketplace Blueprints The execution order in a pre-built blueprint from the Marketplace is incorrect for the user’s environment. Modify the blueprint by adding or adjusting white arrows to create the required task sequence. "How do you modify a Marketplace blueprint to ensure correct execution order for your specific environment?"
Service Startup Failures in Multi-VM Blueprints Services fail to start in the correct order in a multi-VM deployment. Add appropriate white arrows to manually control the startup sequence or ensure macros are correctly used in scripts. "How can you control the startup order of multiple VMs in a Calm blueprint?"

4. Best Practices for Exam Preparation

  • Understand Arrow Types:
    • Be clear on the differences between orange and white arrows, how they are created, and their specific purposes.
  • Practice Troubleshooting Scenarios:
    • Use hands-on labs to practice configuring dependencies and handling common troubleshooting scenarios.
  • Focus on Real-World Examples:
    • Work through practical examples involving multiple services (e.g., database, web server, load balancer) to understand how arrows affect execution.
  • Review Day 2 Operations and Runbooks:
    • Understand how to manage and troubleshoot Day 2 operations and runbooks using both arrow types.
  • Prepare for Dependency Management:
    • Be ready to answer questions about how to manage dependencies in various blueprint configurations, especially when dealing with multiple services or tasks.

By mastering these troubleshooting concepts and scenarios, you'll be well-prepared to handle questions related to dependencies, task execution order, and blueprint management on the NCP-MCA 6.5 exam.

Explanation: Can Arrows Be Inside Tasks and to/from an App/Service/VM?

1. Types of Arrows in Calm Blueprints

In Nutanix Calm, arrows represent dependencies and the order of operations within a blueprint. There are two types of arrows commonly used:

  • Orange Arrows: Automatically generated based on macro references within scripts. These arrows represent the execution order of tasks.
  • White Arrows: Manually drawn to create logical dependencies between services or tasks, ensuring that certain actions occur before or after others.

2. Arrows Inside Tasks and Between App/Service/VM

  • Arrows Inside Tasks:

    • Orange Arrows: Can effectively appear "inside" tasks when tasks reference properties or outputs of other services using macros. For example, if Task A in Service 1 needs the IP address of a VM in Service 2 (@@{Service2.address}@@), an orange arrow will automatically connect the two tasks to show this dependency.
    • White Arrows: Cannot be drawn directly "inside" tasks. However, they can connect two tasks within or across services by drawing from one service task to another in the Calm blueprint canvas.

  • Arrows Between Apps/Services/VMs:

    • Orange Arrows: Automatically created when a dependency is established between tasks in different services or VMs, using macros. This shows that one service or VM must complete a certain task before another service or VM can begin.
    • White Arrows: Manually drawn to indicate dependencies between entire services or VMs, ensuring that one must be fully operational or shut down before another begins its task.

3. Practical Example Scenarios with Arrows

Let's break down how these arrows would work in different scenarios, as mentioned in your example.

Scenario: Multi-VM Blueprint with Database Service, Web Server Service, Load Balancing Service

  • Example Components:

    • Database Service (DB Service)
    • Web Server Service (Apache)
    • Load Balancing Service (HAProxy)

  • Arrows Usage:

    • Orange Arrows:
      • Creation: Generated automatically when a task in one service references a property of another. For example, in the HAProxy load balancing service, if the script includes a macro like @@{WebServer.address}@@, an orange arrow will appear from the Web Server service to the Load Balancer service to indicate that the load balancer task depends on the Web Server’s IP address.
      • Purpose: To ensure that tasks in dependent services execute in the correct order (e.g., database starts before the web server, which starts before the load balancer).
    • White Arrows:
      • Creation: Manually drawn to define explicit dependencies between services or tasks. For example, you might draw a white arrow from the Web Server service to the HAProxy service to ensure that HAProxy does not start until the web server is up and running.
      • Purpose: To enforce a specific sequence or dependency logic that isn't automatically defined by macro references.
Scenario: Adding Dependencies
  • Adding Dependencies:
    • You might need to add dependencies between the Load Balancer (HAProxy) and Web Server services.
    • White Arrows:
      • How to Add: Click the “Create Dependency” icon on the Calm blueprint canvas, then draw from the HAProxy service to the Web Server service.
      • Result: A white arrow appears, indicating that the load balancer service must wait for the web server service to be ready.
    • Orange Arrows:
      • If any script in HAProxy contains @@{WebServer.address}@@, an orange arrow is automatically created to represent that HAProxy tasks cannot execute until the web server’s IP is assigned.
Scenario: Day 2 Operations
  • Day 2 Operations:
    • Definition: These are actions taken after an application is deployed, such as scaling, updating, or restarting services.
    • Arrows:
      • Orange Arrows: Automatically appear when tasks in Day 2 operations use macros referencing other services or tasks (e.g., scaling a service based on the current load of another service).
      • White Arrows: Used to manually ensure that certain Day 2 operations are executed in the right order (e.g., backup tasks before upgrade tasks).
Scenario: Configuring and Executing Runbooks
  • Runbooks:
    • Definition: A collection of tasks or scripts that automate routine operational procedures.
    • Arrows:
      • Orange Arrows: Automatically connect tasks that depend on outputs or properties of previous tasks, using macros.
      • White Arrows: Manually added to control the execution flow of the tasks in the runbook, ensuring tasks execute in a defined order.

Summary: Exam Focus on Arrow Types in Calm Blueprints

  • Can Arrows Be Inside Tasks?:

    • Yes, orange arrows can effectively connect tasks "inside" services or between services when scripts use macros.
    • White arrows are not "inside" tasks but connect tasks or services to establish a specific order or dependency manually.

  • Common Exam Questions:

    • What do orange arrows indicate in Calm blueprints?
    • How do you create and use white arrows in a Calm blueprint?
    • How would you troubleshoot a failed deployment where no orange arrows are present?
    • What is the impact of missing white arrows in a multi-VM blueprint?

By understanding these different scenarios and how arrows are used to manage dependencies and order of operations, you will be well-prepared for the NCP-MCA 6.5 exam.

According to the official Nutanix documentation, the arrows in Calm blueprints represent dependencies and the order of execution for tasks and services:

Arrow Colors in Calm Blueprints

  1. Orange Arrows:

    • Creation: Automatically generated by the system.
    • Purpose: Indicate the order of execution based on macro references within tasks.
    • Example Use Case: When a task in a blueprint script references a property from another service (e.g., @@{DB.address}@@ in the "App Package Install"), the orange arrow automatically indicates that the "App Package Install" task cannot run until the DB service is up and running. This ensures that tasks execute in the correct order.
    • Testing on NCP-MCA 6.5:
      • You may be asked to identify what orange arrows signify in a Calm blueprint or to recognize how they are created and used.
      • Possible questions: "What does an orange arrow indicate?" or "How are orange arrows generated in Nutanix Calm?"

  2. White Arrows:

    • Creation: Manually drawn by the user.
    • Purpose: Represent logical dependencies between services, where the execution order is explicitly defined by the user.
    • Example Use Case: To manually specify that a load balancer (e.g., HAProxy) should only start after the web server is running, you draw a white arrow from the web server service to the HAProxy service. This ensures proper startup or shutdown sequences.
    • Testing on NCP-MCA 6.5:
      • You may need to understand how to create a white dependency arrow or to explain their purpose in a blueprint.
      • Possible questions: "How do you create a white dependency arrow?" or "What is the purpose of a white arrow?"

Arrows Inside Tasks and Between Services/VMs

Arrows can be used inside tasks to show dependencies between actions within a single service or VM. They can also be used between applications, services, or VMs to indicate dependencies or execution order.

  • Exercise Context: For example, when creating a load-balancing service, you might define a sequence where the HAProxy service starts after the web server service is up, using arrows to represent this dependency. This setup is critical when configuring services like multi-VM blueprints, database services, web server services, or any service that requires specific startup or shutdown sequences.

Official Materials Summary

The official Nutanix materials provide detailed guidance on how to use these arrows to define the correct execution order and dependencies within a Calm blueprint. They emphasize using orange arrows for automatically generated task dependencies based on macros, and white arrows for manually defining service dependencies where required .

For further details, please refer to: