On openstack wallaby version openstack server list result too slow :

| GET http://example.com:35357/v3                                             |  0.040385 |
| POST http://example.com:35357/v3/auth/tokens                                |   0.49567 |
| GET http://example.com:9292/                                                      |  0.011694 |
| GET http://example.com:8774/v2.1/servers/detail?all_tenants=True                  | 16.032512 |
| GET http://example.com:9292/v2/images                                             |  0.241679 |
| GET http://example.com:9292/v2/images?marker=b17469eb-4548-4fbb-b871-5880323a7a76 |  0.205339 |
| GET http://example.com:9292/v2/images?marker=eb00ee00-4401-4e59-bf92-602be2e45c4a |  0.204854 |
| GET http://example.com:9292/v2/images?marker=edf7d33a-286a-4a00-a8d8-4b0055d06093 |  0.203524 |
| GET http://example.com:9292/v2/images?marker=75ab289d-90ce-496c-97a4-6fdd247c862a |  0.215708 |
| GET http://example.com:9292/v2/images?marker=b4eaf24c-94dc-4f2f-bd54-3eecbf290d75 |   0.28073 |
| GET http://example.com:8774/v2.1/flavors/detail?is_public=None                    |  0.641211 |
| Total                                                                               | 18.573306

as you see nova api takes 16 seconds to load . I have one project with 1100 instance on it