Solution Concepts Flashcards
How do you use - Using clusters for large-scale technical computing in the cloud
The concepts and technologies underlying cluster computing have developed over the past few decades, and are now mature and mainstream. Migrating the software stack to Google Cloud can add a few wrinkles, but also offers a number of opportunities to decrease cost and alleviate existing bottlenecks in today’s high-performance computing environments. This guide provides an overview of the technologies, the challenges, and the current crop of solutions for running computational clusters on Google Cloud.
Cluster computing aggregates and coordinates a collection of machines to work together to solve a task. Clusters typically have a single head node (sometimes called a master node), some number of compute nodes, and possibly a few other specialty nodes. The head node is the brains of the system and is responsible for:
Registering compute nodes into the system.
Monitoring the nodes.
Allocating jobs to particular nodes.
A cluster is composed of a head node and a set of compute nodes.
How can you design resilient systems with GCP?
A resilient system is a system that can withstand a certain amount of failures or disruptions without interrupting your service or affecting your users’ experience using your service. While Compute Engine makes every effort to prevent such disruptions, certain events are unpredictable, and it’s best to be prepared for these events.
Types of failures
Unexpected single VM failure
Unexpected single VM failures can be due to hardware or system failure. You can mitigate these events by using persistent disks and startup scripts to save your data and re-enable software after you restart the VM.
Unexpected single VM reboot
At some point in time, you might experience an unexpected single VM failure and reboot. Unlike an unexpected single VM failure, Compute Engine automatically reboots your VM after it fails. To help mitigate these events, back up your data, use persistent disks, and use startup scripts to quickly re-configure software.
Zone or region failures
Zone and region failures are rare failures that can cause all of your VMs in a given zone or region to be inaccessible or fail. To mitigate these failures, create diversity across regions and zones and implement load balancing. You should also back up your data or replicate your persistent disks across multiple zones.
Tips for designing resilient systems
To help mitigate VM failures, design your application to be resilient against failures, network interruptions, and unexpected disasters. A resilient system gracefully handles failures, for example, by redirecting traffic from an inaccessible VM to a live VM or by automating tasks on reboot.
Here are some general tips to help you design a resilient system against failures.
Use live migration
Use zone-specific internal DNS names
Create groups of VMs
Use load balancing
Use startup and shutdown scripts
Back up your data
What are best practices for using images?
mage management best practices
This solution provides in-depth guidance on how to manage Compute Engine images. Images provide the base operating environment for applications that run in Compute Engine, and they are critical to ensuring your application deploys and scales quickly and reliably. You can also use images to archive application versions for disaster recovery or rollback scenarios.
Understanding images
An image in Compute Engine is a cloud resource that provides a reference to an immutable disk. That disk representation is then encapsulated using a few data formats.
Understanding images.
An image is a bundle of the raw bytes used to create a prepopulated hard disk. Written on any formatted disk is a partition table that points to one or more partitions that contain data. For an image to be bootable, it must contain the following:
A partition table: either a master boot record or GUID partition table
A bootable partition
For a disk to be imported as a Compute Engine image, the disk’s bytes must be written to a file named disk.raw.
After the complete sequence of bytes from the disk are written to the file, the file is archived using the tar format and then compressed using the GZIP format. You can then upload the resulting *.tar.gz file to Cloud Storage and register it as an image in Compute Engine, as shown in the preceding diagram. After you register an image, you can use it to create exact replicas of the original disk in any region of Google Cloud. The newly registered images are often used as boot volumes for Compute Engine instances.
What are allow vs deny policies?
Allow policies allow members specific roles tied to a resource.
Only 1 policy per resource.
What is an IAM Policy
IAM Policy
An IAM policy defines and enforces what roles are granted to which identities. Each role attached to an identity is a binding.
Policy has a set of bindings.
This policy is attached to a resource. If we had 20 Compute Engine instances, they will each have one IAM policy. Importantly, if you assign the policy to a GCP project, the user gains the specified roles across the project.
