No valid host was found. There are not enough hosts available-----openstack建虛擬機直接報錯
目錄
一、問題現象：
本次環境中只有一個計算節點，創建虛擬機直接報錯，使用nova show 看到報錯如下圖：
"message": "No valid host was found. There are not enough hosts available.", "code": 500
二、解決思路：
1、查看計算節點的nova-compute 日志,發現如下日志：
2019-11-21 19:47:09.484 8 ERROR nova.scheduler.client.report [req-cbc37e88-16be-4b5b-be98-d889cd1b01dc - - - - -] [req-a5a6d438-3f63-49aa-9dd2-98d061b122b4] Failed to create resource provider record in placement API for UUID d878a164-6499-43d4-9772-b77107a1bb8c. Got 409: {"errors": [
{"status": 409, "request_id": "req-a5a6d438-3f63-49aa-9dd2-98d061b122b4", "detail": "There was a conflict when trying to complete your request.\n\n Conflicting resource provider name: compute1 already exists. ", "title": "Conflict"}
2019-11-21 19:47:09.485 8 ERROR nova.compute.manager [req-cbc37e88-16be-4b5b-be98-d889cd1b01dc - - - - -] Error updating resources for node compute1.: ResourceProviderCreationFailed: Failed to create resource provider compute1
發現ResourceProviderCreationFailed: Failed to create resource provider compute1 ，發現resource Provider 創建失敗。懷疑數據庫resource provider 表沒有建出來，繼續查看nova-nova-scheduler.log。
2、查看nova-scheduler.log
2019-11-21 20:18:43.360 29 INFO nova.filters [req-448bd5fa-ddc8-45d9-9b8b-a63bdb691335 e0111848d3904a7288df61cac5163f4f 9be97009f556459cb1814232dbedb4a3 - default default] Filter RetryFilter returned 0 hosts
2019-11-21 20:18:43.362 29 INFO nova.filters [req-448bd5fa-ddc8-45d9-9b8b-a63bdb691335 e0111848d3904a7288df61cac5163f4f 9be97009f556459cb1814232dbedb4a3 - default default] Filtering removed all hosts for the request with instance ID 'c9542c1c-191e-49f2-815a-fdcacc081af6'. Filter results: ['RetryFilter: (start: 0, end: 0)']
3、進數據查看數據庫表
mysql> use nova_api;
mysql[nova_api] > select * from resource_providers;
+---------------------+---------------------+----+--------------------------------------+----------+------------+----------+------------------+--------------------+
| created_at | updated_at | id | uuid | name | generation | can_host | root_provider_id | parent_provider_id |
+---------------------+---------------------+----+--------------------------------------+----------+------------+----------+------------------+--------------------+
| 2019-11-21 06:17:39 | 2019-11-21 06:17:41 | 3 | 16d1bd53-7919-4fef-9a11-a0e98c149823 | compute1 | 1 | NULL | 3 | NULL |
+---------------------+---------------------+----+--------------------------------------+----------+------------+----------+------------------+--------------------+
1 row in set (0.00 sec)
發現有數據。重新創建虛擬機，依然會發生報錯，
4、嘗試將compute節點從nova service-list中刪除，並重新加入到集群中
# 停掉compute節點的nova-compute 服務
nova service-delete <計算節點的uuid>
# 開啟計算節點的nova-compute服務，讓計算節點重新注冊
嘗試創建虛擬機，發現還是報錯。返回去，查看nova-compute的日志發現 There was a conflict when trying to complete your request.\n\n Conflicting resource provider name: compute1 already exists. 。提示矛盾。
5、再次進入數據庫，執行 select * from resource_providers;
mysql> use nova_api;
mysql[nova_api] > select * from resource_providers;
+---------------------+---------------------+----+--------------------------------------+----------+------------+----------+------------------+--------------------+
| created_at | updated_at | id | uuid | name | generation | can_host | root_provider_id | parent_provider_id |
+---------------------+---------------------+----+--------------------------------------+----------+------------+----------+------------------+--------------------+
| 2019-11-21 06:17:39 | 2019-11-21 06:17:41 | 3 | 16d1bd53-7919-4fef-9a11-a0e98c149823 | compute1 | 1 | NULL | 3 | NULL |
+---------------------+---------------------+----+--------------------------------------+----------+------------+----------+------------------+--------------------+
1 row in set (0.00 sec)
發現新注冊的計算節點，但是resource_providers的uuid 沒有發生變化，懷疑是注冊compute節點的時候，並沒有更新resource_providers，嘗試刪除resource_providers;
6、查找官網，找到了操作 resource_providers的openstack命令,執行如下操作。
相關文檔：https://docs.openstack.org/osc-placement/latest/cli/index.html
# 安裝osc-placement 軟件包，生成命令行工具
# 執行如下命令：
export OS_PLACEMENT_API_VERSION=1.10
openstack allocation candidate list --resource VCPU=1
# 查看當前resource provider
[root@control1 ~]# openstack resource provider list
+--------------------------------------+----------+------------+
| uuid | name | generation |
+--------------------------------------+----------+------------+
| 16d1bd53-7919-4fef-9a11-a0e98c149823 | compute1 | 2 |
+--------------------------------------+----------+------------+
# 停止計算節點nova-compute服務
# 從service 中刪除compute1
nova service-delete <uuid>
# 刪除當前resource provider
openstack resource provider delete 16d1bd53-7919-4fef-9a11-a0e98c149823
# 重啟nova-compute服務，讓其自動注冊
# 查看當前resource provider
[root@control1 ~]# openstack resource provider list
+--------------------------------------+----------+------------+
| uuid | name | generation |
+--------------------------------------+----------+------------+
| b32cd7b5-26c6-4998-97f1-79fa2315871b | compute1 | 2 |
+--------------------------------------+----------+------------+
# # 執行如下命令，驗證是否更新了數據
export OS_PLACEMENT_API_VERSION=1.10
openstack allocation candidate list --resource VCPU=1
執行創建雲主機，雲主機成功創建。