PCA-Assorted

Question 1

What is the default limit on API calls per second in BigQuery, and what can we do if we need faster ingestion ?

Answer 1

100 API calls per second. Use PubSub for faster ingestion, possibly with Dataflow if deduplication/ ordering is a concern.

Question 2

How do we temporarily allow some users to upload data to a Google Cloud Store bucket, if they do NOT have google accounts.

Answer 2

Signed URLs give the users time limited read/ read-write access for any bearer of the URL, even without a google account.

Question 3

What is the fastest kind of a disk i can attach to a Compute VM which will not disappear when the VM is stopped.

Answer 3

Persistent SSD.
Note:
Local SSD disappears on stopping/ deleting VM
SSD is faster than the regular disks

Question 4

What is the difference between labels and tags placed on a Compute VM ?

Answer 4

Tags are placed for firewalls / network configuration.
Labels are used for billing and cost management.

Question 5

Which user is the startup script on a VM run as ?

Answer 5

root.
Note: startup scripts are run after creating all users for whom SSH access is configured in metadata

Question 6

What are Persistent Connections in AppEngine

Answer 6

AppEngine supports persistent connections using WebSockets that last to an hour. Used for stock quotes, continuous location updates and like.

Note:
If the device stops/ disconnects, the connection is lost like any other connection.

Question 7

Can a Cloud Function be written in any programming language ?

Answer 7

No, supported platforms are - Node.js, Python, Go, Java, .NET Core, and Ruby

Question 8

What is the max time limit a Cloud Function must finish in ?

Answer 8

~9 minutes

Question 9

Can Cloud Run store state ?

Answer 9

Not strictly - because it is not guaranteed the next call is served by the same instance, but instances can have global variables that can be used to create caches of costly to initialize objects that are lazy populated.

Question 10

Can a Cloud Function store some state ?

Answer 10

No - A Cloud Function has no app context. It will need to store state externally, or AppEngine may be used

Question 11

Can DataPrep connect to an online source outside GCP or SaaS service ?

Answer 11

No - data must be stored in GCP to be cleaned using DataPrep

Question 12

We have a running Compute VM. How do we deploy a MIG duplicating this one VM ?

Answer 12

Create Snapshot -> Create Image -> Instance Template -> MIG
Instance template can be created only from an image, not directly from a snapshot. A MIG needs to be created from a template, not image

Question 13

What GCP resources can be created without a VPC ?

Answer 13

Most managed GCP resources - Store buckets, Cloud Run, Cloud Functions can be created without VPC.
** Compute VM and GKE cluster need a VPC **

Question 14

How do you configure a Compute VM to access Storage so that it can download it’s initial scripts from Cloud Storage ?

Answer 14

Enable Private Google Access on the subnet.

Question 15

Name 2 services that scale to 0, and 2 that do not

Answer 15

Compute VM and GKE do NOT scale to zero since they are unmanaged services.

Most managed services such as Cloud functions, Cloud Run and AppEngine (Standard) scale to zero.

Note: AppEngine (Flexible) does NOT scale to zero.

Question 16

A log that records all changes made in the database

Answer 16

Binary log / Transaction Log

Question 17

A service to schedule events, which will call the configured event handler - App Engine, HTTP Endpoint, PubSub

Answer 17

Cloud Scheduler