一般用途服務層級 - Azure SQL DatabaseGeneral purpose service tier - Azure SQL Database

注意

VCore 為基礎的購買模型中的一般用途服務層級, 在以 DTU 為基礎的購買模型中稱為「標準」服務層級。The general-purpose service tier in the vCore-based purchasing model is called the standard service tier in the DTU-based purchasing model. 如需以虛擬核心為基礎的購買模型與以 DTU 為基礎的購買模型的比較,請參閱 Azure SQL Database 購買模型和資源For a comparison of the vCore-based purchasing model with the DTU-based purchasing model, see Azure SQL Database purchasing models and resources.

Azure SQL Database 是以會針對雲端環境調整的 SQL Server 資料庫引擎架構為基礎,以確保 99.99% 的可用性 (即使在基礎結構失敗的情況下)。Azure SQL Database is based on SQL Server database engine architecture adapted for the cloud environment in order to ensure 99.99% availability even in the cases of infrastructure failures. Azure SQL Database 中使用三個服務層級,每個服務層級具有不同的架構模型。There are three service tiers that are used in Azure SQL Database, each with different architectural models. 這些服務層級為:These service tiers are:

  • 一般用途General purpose
  • 業務關鍵Business critical
  • 超大規模Hyperscale

一般用途服務層級的架構模型是以計算和儲存體的分隔為基礎。The architectural model for the general-purpose service tier is based on a separation of compute and storage. 此架構模型仰賴 Azure Blob 儲存體的高可用性和可靠性,可以透明的方式複寫資料庫檔案,並保證當基礎結構發生失敗時也不會遺失資料。This architectural model relies on high availability and reliability of Azure Blob storage that transparently replicates database files and guarantees no data loss if underlying infrastructure failure happens.

下圖顯示標準架構模型中具有分隔計算和儲存體層的四個節點。The following figure shows four nodes in standard architectural model with the separated compute and storage layers.

分隔計算與儲存體

在一般用途服務層的架構模型中, 有兩個層級:In the architectural model for the general-purpose service tier, there are two layers:

  • 無狀態計算層,執行 sqlservr.exe 流程並且僅包含暫時性和快取資料 (例如計畫快取、緩衝集區、列儲存集區)。A stateless compute layer that is running the sqlservr.exe process and contains only transient and cached data (for example – plan cache, buffer pool, column store pool). 此無狀態 SQL Server 節點是由 Azure Service Fabric 操作,可初始化流程、控制節點的健康情況,並在必要時執行故障轉移至其他位置。This stateless SQL Server node is operated by Azure Service Fabric that initializes process, controls health of the node, and performs failover to another place if necessary.
  • 具狀態資料層,包含儲存在 Azure Blob 儲存體中的資料庫檔案 (.mdf/.ldf)。A stateful data layer with database files (.mdf/.ldf) that are stored in Azure Blob storage. Azure Blob 可確保任何資料庫檔案中放置的任何記錄都不會遺失資料。Azure Blob storage guarantees that there will be no data loss of any record that is placed in any database file. Azure 儲存體具有內建的資料可用性/備援,即使 SQL Server 流程損毀,也可以確保保留資料檔案中記錄檔或頁面中的每項記錄。Azure Storage has built-in data availability/redundancy that ensures that every record in log file or page in data file will be preserved even if SQL Server process crashes.

每當升級資料庫引擎或作業系統,部份的基礎結構失敗,或者在 SQL Server 流程中偵測到某些關鍵問題時,Azure Service Fabric 都會將無狀態 SQL Server 流程移至另一個無狀態計算節點。Whenever database engine or operating system is upgraded, some part of underlying infrastructure fails, or if some critical issue is detected in SQL Server process, Azure Service Fabric will move the stateless SQL Server process to another stateless compute node. 主要節點發生容錯移轉時,會有一組備用節點等候執行新的計算服務,以便將容錯移轉的時間縮到最短。There is a set of spare nodes that is waiting to run new compute service if a failover of the primary node happens in order to minimize failover time. Azure 儲存體層中的資料不受影響,而資料/記錄檔會附加到新初始化的 SQL Server 流程。Data in Azure storage layer is not affected, and data/log files are attached to newly initialized SQL Server process. 此流程可保證 99.99% 的可用性,但由於轉換時間和新 SQL Server 節點以冷快取啟動,可能會對正在執行的繁重工作負載產生一些效能影響。This process guarantees 99.99% availability, but it might have some performance impacts on heavy workload that is running due to transition time and the fact the new SQL Server node starts with cold cache.

選擇此服務層級的時機When to choose this service tier

一般目的服務層級是 Azure SQL Database 中的預設服務層級,專供大部分的一般工作負載使用。General Purpose service tier is a default service tier in Azure SQL Database that is designed for most of the generic workloads. 如果您需要具有 99.99% SLA 的完全受控資料庫引擎, 且在大部分情況下都符合 Azure SQL IaaS 的儲存體延遲為5到10毫秒, 則您可以選擇一般用途層。If you need a fully managed database engine with 99.99% SLA with storage latency between 5 and 10 ms that match Azure SQL IaaS in most of the cases, General Purpose tier is the option for you.

後續步驟Next steps