slow performance after automatic network architecture upgrade

[jh26]

We got the following message from GCP about our database:

Dear Cloud SQL user,

Your instance production-0 is scheduled to undergo a network architecture upgrade on March 9, 2025 at 05:00:00 UTC. The Cloud SQL instance mentioned in this notification is running on the old network architecture and will be automatically upgraded to the new network architecture

The instance now shows as being under the "new network architecture".

The problem is that we are seeing significantly worse performance this week that we were prior to the upgrade.

For example, here is our daily performance check for the past two weeks:

2025-03-13 recent_cases >= 4 : 78.79% (8,265 out of 10,490)
2025-03-12 recent_cases >= 4 : 79.34% (8,474 out of 10,681)
2025-03-11 recent_cases >= 4 : 78.35% (9,276 out of 11,839)
2025-03-10 recent_cases >= 4 : 78.07% (9,228 out of 11,820)
..
..
2025-03-07 recent_cases >= 4 : 0.78% (70 out of 9,014)
2025-03-06 recent_cases >= 4 : 1.06% (112 out of 10,565)
2025-03-05 recent_cases >= 4 : 1.98% (220 out of 11,088)
2025-03-04 recent_cases >= 4 : 1.61% (185 out of 11,491)
2025-03-03 recent_cases >= 4 : 1.31% (153 out of 11,670)

This is a 10x increase in the number of slow DB queries. What was an acceptable level before is now a real problem for us.

There have been no changes in our application, database schema, or database configuration. Just the automatic architecture migration.

Can someone give me some ideas of where to start looking for the cause of this?

thanks!

[Joy_S]

Hi @jh26,

Welcome to Google Cloud Community!

One possible reason for this issue is the extra IP space Cloud SQL is using for private IP instances. With the recent network upgrade, if you have two or more private IP instances in the same region, Cloud SQL temporarily takes up an additional /24 subnet range from your Private Services Access (PSA) IP allocation. This is just a temporary adjustment to support the transition and won’t be a permanent change.

In the meantime, if you continue to experience slow DB queries, you may contact Google Cloud Support. They can investigate your specific project and account for any underlying issues. 

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