Exam Professional Cloud Architect All Questions

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Exam Professional Cloud Architect topic 1 question 86 discussion

Actual exam question from Google's Professional Cloud Architect

Question #: 86
Topic #: 1

[All Professional Cloud Architect Questions]

You have been engaged by your client to lead the migration of their application infrastructure to GCP. One of their current problems is that the on-premises high performance SAN is requiring frequent and expensive upgrades to keep up with the variety of workloads that are identified as follows: 20 TB of log archives retained for legal reasons; 500 GB of VM boot/data volumes and templates; 500 GB of image thumbnails; 200 GB of customer session state data that allows customers to restart sessions even if off-line for several days.
Which of the following best reflects your recommendations for a cost-effective storage allocation?

A. Local SSD for customer session state data. Lifecycle-managed Cloud Storage for log archives, thumbnails, and VM boot/data volumes.
B. Memcache backed by Cloud Datastore for the customer session state data. Lifecycle-managed Cloud Storage for log archives, thumbnails, and VM boot/data volumes.
C. Memcache backed by Cloud SQL for customer session state data. Assorted local SSD-backed instances for VM boot/data volumes. Cloud Storage for log archives and thumbnails.
D. Memcache backed by Persistent Disk SSD storage for customer session state data. Assorted local SSD-backed instances for VM boot/data volumes. Cloud Storage for log archives and thumbnails.

Show Suggested Answer

Suggested Answer: B 🗳️

by ffk at Oct. 30, 2019, 7:44 a.m.

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OSNG

Highly Voted 4 years, 7 months ago

B is correct. WHY NOT OTHERS. A: is wrong Local SSD in non-persistent therefore cannot be used for session state (as questions also need to save data for users who are offline for several days). C: Again Local SSD cannot be used for boot volume (because its Non-persistent again) and always used for temporary data storage. D: Same reason as C. WHY B? Left with B that's why, but the question is how to store Boot/Data volume on Cloud Storage? - Storing other type of data is easy but most comments were about boot volume. - Boot volume can be stored to Cloud Storage by creating an Custom Image. https://cloud.google.com/compute/docs/images/create-delete-deprecate-private-images#selecting_image_storage_location ---- Upvote if agree for the clarification of others ----

upvoted 114 times

rsamant

4 years, 1 month ago

Cloud Storage can be used to store image but it can't be used for boot.

upvoted 8 times

Davidik79

3 years, 3 months ago

"If you need to move your Compute Engine boot disk data outside of your Compute Engine project, you can export a boot disk image to Cloud Storage as a tar.gz file" Doc ref: https://cloud.google.com/compute/docs/images/export-image

upvoted 1 times

Ishu_awsguy

2 years, 11 months ago

Customer is migrating their apps , not only data. So B is wrong. App wont work with data volumes in compresses format on cloud storage ( obvious)

upvoted 2 times

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Chute5118

2 years, 11 months ago

Cloud Volumes Service has the ability to send volumes of the CVS service type to Google Cloud Object Storage for long-term backup and archive. This data-management feature complements volume snapshots, which provide access for development or test use cases that require short-term recovery https://cloud.google.com/architecture/partners/netapp-cloud-volumes/back-up

upvoted 1 times

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Manh

3 years, 10 months ago

it's B. the question is all about storing data. B is right answer

upvoted 2 times

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Ishu_awsguy

2 years, 11 months ago

How can u use cloud storage for VM boot/data volumnes ? B is wrong

upvoted 1 times

Ishu_awsguy

2 years, 11 months ago

All the options are debatable and have some flaw. But closes answer is B although it has a flaw mentioned above but is still better than other options

upvoted 3 times

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neversaynever

3 years, 5 months ago

Answer is D - boot volumes (not boot images) cannot come from Cloud Storage - so B is not the answer.

upvoted 5 times

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Ishu_awsguy

2 years, 11 months ago

Guys I think its a english error. The last line need to be read carefully Decouple the line after , and Vm boot/data volumes. I think they mean to use vm persistent disks for boot and data volumes. B is the answer

upvoted 2 times

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siumk

Highly Voted 5 years, 4 months ago

IMHO Answer is B: Memcache backed by Cloud Datastore https://cloud.google.com/appengine/docs/standard/python/memcache Compute Engine image can be stored in Cloud Storage https://cloud.google.com/solutions/image-management-best-practices 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.

upvoted 17 times

Ayzen

5 years, 2 months ago

The problem with B is that they are using SAN for data volumes of working VMs, not just to store templates/images. All answers here are quite bad. But I would go with D, as they are talking about several days of saving users' stale session data, which is something that can be accomplished with SSD.

upvoted 10 times

Bijesh

4 years, 8 months ago

@ayzen yes. IS cloud datastore optimized to handle such a data (200GB)

upvoted 1 times

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Toothpick

Most Recent 11 months, 3 weeks ago

None of these provide an effective method of storing boot/data volumes The correct approach would be to create persistent disk Drives for boot/data volumes directly and go with B or D for the remainder of requirements.

upvoted 2 times

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otts

1 year, 6 months ago

B is correct. the question lays emphasis on a cost-effective storage allocation, and persistent disks are costly than B (that rules out D)

upvoted 1 times

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e5019c6

1 year, 6 months ago

Selected Answer: D

This is a troublesome question... IMHO, it's D. I was between C & D, but seeing how they stored the customer session data as files, storing it in SQL would require refactoring, and maybe higher latencies. I'm against B because of the latency added by booting & loading data off Cloud Storage, since it adds network latency to the equation. BUT this is assuming the method of using cloud storage is via gcsfuse, that is, using the bucket as a HD. Now if the way of using it is via image of the disk that is loaded when the instance starts, that would be ok. And that's what I expected of option D, that it would load an image of the boot/data volume in it's non-persistent disks. No 'persistent' data would be stored in it, so anything lost when it's shutdown can be ignored.

upvoted 1 times

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AdityaGupta

1 year, 9 months ago

Selected Answer: D

D is correct answer because - Memcache backed by Persistent Disk SSD storage for customer session state data. - Persistent disk will ensure that Session data is preserved evern if not used for long time. - Assorted local SSD-backed instances for VM boot/data volumes. Provides faster boot up for VMs. (There is no requirement for persistent storage) - Cloud Storage for log archives and thumbnails. - For low cost and scalable solution.

upvoted 1 times

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ductrinh

1 year, 9 months ago

d wrong because of local ssd cannot use for boot image. its temporary and will be cleared if vm was suspended >> so chose b

upvoted 2 times

A21325412

1 year, 8 months ago

A lot of folks keep saying D is wrong because of "local SSD". It never mentioned "local" in option D. It said "Persistent Disk SSD". https://cloud.google.com/compute/docs/disks I would definitely choose D.

upvoted 2 times

A21325412

1 year, 8 months ago

My bad, I was focusing on the memcache. I would choose C. The "assorted local ssd" for VM boot/data volumes can't work, as Local SSDs are ephemeral, meaning it's lost if the VM instance is stopped or deleted.

upvoted 1 times

A21325412

1 year, 8 months ago

I think I'm tired. I meant to write Option B as the correct answer. Memcache backed by Cloud Datastore, etc.

upvoted 1 times

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Murtuza

1 year, 10 months ago

Local SSD means Ephemeral ( Temp Disk ) so do not confused with PERSISTENT disk ( Permanent Disk ). The data that you store on a local SSD persists only until the instance is stopped or deleted.

upvoted 1 times

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