• Data Warehouse Service

dws
  1. Help Center
  2. Data Warehouse Service
  3. Developer Guide
  4. System Overview
  5. HA Transaction Processing

HA Transaction Processing

DWS manages cluster transactions, the basis of HA and failovers. This ensures speedy fault recovery, guarantees the ACID properties for transactions and after a recovery, and enables concurrent control.

Fault Rectification

DWS provides an HA mechanism to reduce the service interruption time when a cluster is faulty. It protects key user programs to continuously provide external services, minimizing the impact of hardware, software, and human faults on services and ensuring service continuity.

  • Hardware HA: Disk RAID, switch stacking, NIC bond, and uninterruptible power supply (UPS)
  • Software HA: HA mechanism used for instances in the DWS cluster, such as CNs, GTMs, and DNs)

Transaction Management

  • Transaction blocks are supported. You can run start transaction to explicitly start a transaction block.
  • Single-statement transactions are supported. If you do not explicitly start a transaction, a single statement is processed as a transaction.
  • Distributed transaction management and global transaction information management are supported. This includes gxid, snapshot, timestamp management, distributed transaction status management, and gxid overflow processing.
  • Distributed transactions have ACID properties.
  • Deadlock prevention in a distributed system is supported. Transaction deadlocks are prevented, or transactions are automatically unlocked once deadlocked.