是時候從可用性組中刪除數據庫了嗎？哪個？

在修補作為可用性組一部分的我的一台伺服器時，作為輔助伺服器，我遇到了一些問題 - 真正的問題是可用性組中的一個虛擬伺服器的主機 - 短暫的磁碟空間不足一兩分鐘。

對於這個問題，問題是什麼並不重要。

事實是：

1. 我在可用性組上有 2 台機器，失去了輔助機器。
2. 可用性組參與複製，我收到以下錯誤消息：

複製的事務正在等待下一次日誌備份或鏡像夥伴趕上

通過啟動以下跟踪標誌解決了這個問題：

DBCC TRACEON(1448,-1)

3. 我找到了一些關於我的可用性組的資訊，根據以下腳本，我可以看到一台伺服器已關閉：

從 sys.dm_hadr_cluster_members 中選擇 *

SELECT
gs.primary_replica as 'Primary Server',
DB_NAME(dd.database_id) as 'Database Name',
secondary_recovery_health_desc as 'Secondary Server Health Status',
synchronization_state_desc as 'Synchronization State',
database_state_desc as 'Database State',
--suspend_reason_desc as 'Suspended Reason',
--last_sent_time as 'Last Data Send Time',
--last_received_time as 'Last Data Received TIme',
--last_hardened_time as 'Last Hardened Time',
--last_redone_time as 'Last Redone Time',
--log_send_queue_size as 'Log Send Queue Size',
--log_send_rate as 'Log Send Rate',
--redo_queue_size as 'Redo Queue Size',
--redo_rate as 'Rate of Redo',
--filestream_send_rate as 'Filestream Send Rate',
last_commit_time as 'Last Commit Time',
low_water_mark_for_ghosts as 'Low Water Mark for Ghosts'
FROM sys.dm_hadr_availability_group_states as gs
left outer JOIN sys.dm_hadr_database_replica_states as dd ON gs.group_id = dd.group_id
ORDER BY gs.primary_replica DESC, DB_NAME(dd.database_id) DESC

這個問題上的 always On 腳本也沒有告訴我太多

問題：

我在事務日誌中落後了多少，趕上了一個永遠不會回來的副本？

我需要資訊來解決這個問題：

我應該從可用性組中刪除數據庫嗎？

或者我應該建構一個新伺服器，將其添加到可用性組，等待日誌趕上？

在這種情況下，我決定從可用性組中刪除數據庫。為此，我使用了以下腳本：

-- https://blog.pythian.com/list-of-sql-server-databases-in-an-availability-group/
-- How do we know that this instance is part of Availability Group(s):
SELECT
AG.name AS [Name],
ISNULL(agstates.primary_replica, '') AS [PrimaryReplicaServerName],
ISNULL(arstates.role, 3) AS [LocalReplicaRole]
FROM master.sys.availability_groups AS AG
LEFT OUTER JOIN master.sys.dm_hadr_availability_group_states as agstates
   ON AG.group_id = agstates.group_id
INNER JOIN master.sys.availability_replicas AS AR
   ON AG.group_id = AR.group_id
INNER JOIN master.sys.dm_hadr_availability_replica_states AS arstates
   ON AR.replica_id = arstates.replica_id AND arstates.is_local = 1
ORDER BY [Name] ASC

-- https://blog.pythian.com/list-of-sql-server-databases-in-an-availability-group/
-- How do we get some information about the databases in the Availability Group:
SELECT
AG.name AS [AvailabilityGroupName],
ISNULL(agstates.primary_replica, '') AS [PrimaryReplicaServerName],
ISNULL(arstates.role, 3) AS [LocalReplicaRole],
dbcs.database_name AS [DatabaseName],
ISNULL(dbrs.synchronization_state, 0) AS [SynchronizationState],
ISNULL(dbrs.is_suspended, 0) AS [IsSuspended],
ISNULL(dbcs.is_database_joined, 0) AS [IsJoined],
remove_database='USE [master]' + char(13) + 'ALTER AVAILABILITY GROUP ' + quotename(AG.name ) + char(13) + 'REMOVE DATABASE ' + quotename(dbcs.database_name) + char(13)
FROM master.sys.availability_groups AS AG
LEFT OUTER JOIN master.sys.dm_hadr_availability_group_states as agstates
  ON AG.group_id = agstates.group_id
INNER JOIN master.sys.availability_replicas AS AR
  ON AG.group_id = AR.group_id
INNER JOIN master.sys.dm_hadr_availability_replica_states AS arstates
  ON AR.replica_id = arstates.replica_id AND arstates.is_local = 1
INNER JOIN master.sys.dm_hadr_database_replica_cluster_states AS dbcs
  ON arstates.replica_id = dbcs.replica_id
LEFT OUTER JOIN master.sys.dm_hadr_database_replica_states AS dbrs
  ON dbcs.replica_id = dbrs.replica_id AND dbcs.group_database_id = dbrs.group_database_id
ORDER BY AG.name ASC, dbcs.database_name

引用自：https://dba.stackexchange.com/questions/224693