We migrated from PDNS (Authorative) v4.1.X to v4.9.

We noticed that the PDNS API is not working properly with /api/v1/servers/localhost/zones
it just times out.

Running the same curl command in the old version (4.1) works as expected taking under 1 minute.
We ran other api calls just to be sure is not a connectivity issue and they worked as expected.

This makes PDA unusable, as it relays on GET localhost/zones, to sync its UI...

So to summarize:

• On PDNS v4.1
  • curl -H 'X-API-Key: <apikey>' http://127.0.0.1:8081/api/v1/servers/localhost/zones/domain1.com --> OK
  • curl -H 'X-API-Key: <apikey>' http://127.0.0.1:8081/api/v1/servers/localhost/zones --> OK (under 1 minute)
• On PDNS v4.9
  • curl -H 'X-API-Key: <apikey>' http://127.0.0.1:8081/api/v1/servers/localhost/zones/domain1.com --> OK
  • curl -H 'X-API-Key: <apikey>' http://127.0.0.1:8081/api/v1/servers/localhost/zones --> ERROR (Times out after 10 minutes, also sometimes crashes the whole VM)

We have around 300k domains managed by this PDNS server.

Conducted several more tests:
Test 1:
On the Rocky Linux 9 -->

• Downgraded from 4.9 down to 4.7 within rocky linux OS.
• Pointed to the migrated DB and a snapshot before the schema change.
  It didn't work in any case

Test 2:
On the CentOS 7 -->

• Installed PDNS 4.9. Pointed to the migrated DB and a snapshot before the schema change. It didn't work in any case- - Downgraded PDNS from 4.9 down to 4.2. None minor version worked
• Installed PDNS 4.1.14 --> with this one worked (both pointing to the old/non-schema-migrated and new database)

Environment

• Installed through yum (https://repo.powerdns.com/repo-files/centos-auth-49.repo)
• OS: PDNS4.9 in Rocky Linux 9, PDNS 4.1 in Centos 7
• Backend used: Mysql 8 (RDS aurora.mysql specifically). We ran the old version where the /zones call works connecting to same DB after the DB schema was upgraded and it worked too
• HW Specs: 2vCPU, 4gb RAM (aws - t3.medium) | 2gb SWAP, same specs for both pdns servers (4.9 and 4.1)

Issue Type and Service

• Program: Authoritative
• Issue type: Bug report

Expected behaviour

for the PDNS api to call to http://127.0.0.1:8081/api/v1/servers/localhost/zones to respond under 5 minutes

Actual behaviour

The request timesout (sometimes even crashes the VM)

Other information

This worked perfectly on version 4.1