Exam Professional Cloud Network Engineer topic 1 question 31 discussion

Actual exam question from Google's Professional Cloud Network Engineer

Question #: 31
Topic #: 1

[All Professional Cloud Network Engineer Questions]

You are using a 10-Gbps direct peering connection to Google together with the gsutil tool to upload files to Cloud Storage buckets from on-premises servers. The on-premises servers are 100 milliseconds away from the Google peering point. You notice that your uploads are not using the full 10-Gbps bandwidth available to you. You want to optimize the bandwidth utilization of the connection.
What should you do on your on-premises servers?

A. Tune TCP parameters on the on-premises servers.
B. Compress files using utilities like tar to reduce the size of data being sent.
C. Remove the -m flag from the gsutil command to enable single-threaded transfers.
D. Use the perfdiag parameter in your gsutil command to enable faster performance: gsutil perfdiag gs://[BUCKET NAME].

Show Suggested Answer

Suggested Answer: A 🗳️

by ESP_SAP at Nov. 2, 2020, 4:22 a.m.

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ESP_SAP

Highly Voted 4 years, 3 months ago

Correct Answer is (A) As the question states that the RTT is 100ms thus low transfer rate is due to the TCP window size that is too small. And the solution is to increase the window size .

upvoted 11 times

AzureDP900

2 years, 2 months ago

yes, It is right A. Tune TCP parameters on the on-premises servers.

upvoted 1 times

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saraali

Most Recent 5 months, 3 weeks ago

Selected Answer: A

The correct option is A. The issue of underutilizing the available 10-Gbps bandwidth is often related to TCP configuration. By tuning TCP parameters, such as TCP window size and congestion control algorithms, you can optimize the connection for high-bandwidth, high-latency environments like your 100-ms round-trip time (RTT) peering connection. This adjustment allows gsutil to take better advantage of the available bandwidth.

upvoted 1 times

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vyomkeshbakshi

10 months, 3 weeks ago

Even if you are not aware of all the options, question is asked about what to do on the on prem servers. All other option includes cloud except A

upvoted 1 times

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pk349

2 years ago

A: The TCP window is the maximum number of bytes that can be sent before the ACK must be received. If either the sender or receiver are frequently forced to stop and wait for ACKs for previously sent packets, gaps in the data flow are created, which limits the maximum throughput of the connection.

upvoted 3 times

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GCP72

2 years, 5 months ago

Selected Answer: A

Correct Answer is A

upvoted 1 times

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Taliesyn

2 years, 8 months ago

I would roll with D, since gsutil kindly provides a tool to analyze performance issues.

upvoted 1 times

Taliesyn

2 years, 8 months ago

Ooopsie, read too fast, the answer states that gsutil perfdiag improves performance, which is wrong.

upvoted 2 times

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Luvero

3 years ago

A Like most modern operating systems, Linux now does a good job of auto-tuning the TCP buffers. In some cases, the default maximum Linux TCP buffer sizes are still too small. When this is the case, you can observe an effect called the Bandwidth Delay Product. The TCP window is the maximum number of bytes that can be sent before the ACK must be received. If either the sender or receiver are frequently forced to stop and wait for ACKs for previously sent packets, gaps in the data flow are created, which limits the maximum throughput of the connection.

upvoted 4 times

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