When num of port mappings is substantial, the response time of List API so slow

[Han Guangyu]

Conditions：

I have a Victoria cluster with 1 controller node(also have
nova-compute service) and two compute node. ALL node boasts 128 CPU
cores and 512GB of memory.
I'm a super-user. I have this problem when trying the port forwarding feature.
I established 1500 port mappings for a single floating IP A. At this
point, the response time for the "List Floating IP Port Forwardings"
API[1] becomes remarkably slow, approaching a duration of 9 minutes.

[1] https://docs.openstack.org/api-ref/network/v2/index.html#list-floating-ip-port-forwardings

Step-by-step reproduction steps：

1. Create a floating ip

such as 10.10.16.10

2. At this time, the Port Forwarding List API response time is normal

```shell
floating_ip=10.10.16.10
openstack floating ip port forwarding list $floating_ip
```

3. create 1500 port forwarding for this floating ip

```shell
cat > creat-port-forwarding.sh << EOF
#!/bin/bash

floating_ip=10.10.16.10

source ./admin-openrc

for (( i=11001; i<11500; i++ )); do
        openstack floating ip port forwarding create --internal-ip-address 10.100.1.100 --port 72d49500-ba6e-4e82-bdc2-a72a836ef83e --internal-protocol-port \$i --external-protocol-port \$i --protocol tcp \$floating_ip
done
EOF

chmod +x create-port-forwarding.sh
./create-port-forwarding.sh
```

4. At this point, the response time for the "List Floating IP Port Forwardings"
API becomes remarkably slow, approaching a duration of 9 minutes.

```shell
floating_ip=10.10.16.10
openstack floating ip port forwarding list $floating_ip
```

Version:
Victoria
rpm install

[Christian Rohmann (christian-rohmann)]

Can you reproduce this with a current version of Neutron? Victoria is quite old. Having this appear also in the current code might encourage further analysis and writing a fix for this.

Is this a test environment and could you maybe enable debug logging see where the time is spent within the API? Maybe even down to the SQL queries?

Which ml2 are you using? Which plugins?

[Han Guangyu (han-guangyu)]

Ok, I will try to reproduce this with a current version of neutron. If have log, I will put deubg logging in this bug report.

I use openswitch now.

[Han Guangyu (han-guangyu)]

https://bugs.launchpad.net/neutron/+bug/1911462

This bug has been resolveed in Wallaby， close it