Help Center/ Data Warehouse Service/ User Guide/ DWS Cluster O&M/ Backing Up and Restoring a DWS Cluster/ Configuring DWS Snapshot Parameters
Updated on 2026-07-08 GMT+08:00
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Configuring DWS Snapshot Parameters

You can configure the parameters for creating and restoring a snapshot.

Notes and Constraints

  • This feature applies only to clusters of version 8.2.0 or later. (For clusters of versions earlier than 8.2.0, only some parameters can be configured.)
  • The parameters take effect on all the snapshot creation and restoration tasks.
  • The thread-count configuration is available in cluster 9.1.0.210 and later versions. When Roach initiates a multi-threaded backup of cold and hot tables, and V3 tables, the default number of concurrent threads is set to twice the number of CPU cores.

Procedure

  1. Log in to the DWS console.
  2. In the navigation pane on the left, choose Cluster > Cluster List.
  3. In the cluster list, click the name of the target cluster. The Cluster Information page is displayed.
  4. In the navigation pane, click Snapshots. Click Parameter Configurations. All the configurable parameters of the current cluster will be displayed.
  5. Configure parameters as required. For details, see Table 1.

  6. Click Save.

Snapshot Parameters

Table 1 Snapshot information

Parameter

Type

Description

Default Value

parallel-process

Backup parameter

Number of concurrent processes on each node during Roach backup. This parameter can be configured for clusters earlier than 8.2.0.

The value is the number of DNs on the current node.

compression-type

Backup parameter

Compression algorithm type. This parameter is supported by clusters earlier than 8.2.0.

  • zlib
  • LZ4

LZ4

compression-level

Backup parameter

Compression level. The value range is 0 to 9. This parameter is supported by clusters earlier than 8.2.0.

  • 0: fast backup and no compression
  • 9: slow backup and maximum compression

6

buffer-size

Backup parameter

Buffer size of the Roach upload media, in MB. The value range is 256 to 16384.

256

buffer-block-size

Backup parameter

Data block size of the data file to be read by Roach, in bytes. The value range is 5242880 to 268435456.

67108864

cpu-cores

Backup parameter

Number of CPU cores that can be used when Roach starts multiple threads concurrently

1/2 of the total number of logical CPU cores on the node

master-timeout

Backup parameter

Timeout period for the communication between the Roach master and agent nodes, in seconds. The value range is 600 to 3600.

3600

max-backup-io-speed

Backup parameter

I/O flow control during Roach backup, in MB/s. The value range is 0 to 2048. The value must be greater than the value of buffer-block-size. The value 0 indicates no limit.

0

backup-mode

Backup parameter

Full backup mode.

  • 0: phase-1 backup
  • 1: phase-2 backup

0

cbm-parse-mode

Backup parameter

Incremental backup mode.

  • 0: one-time CBM scan (high memory usage and high performance)
  • 1: multiple CBM scans (stable memory usage and low performance)

0

thread-count

Backup parameter

Number of concurrent threads used when Roach starts multi-thread backup of cold and hot tables and V3 tables. A high parameter value may block access to OBS. This parameter is supported only by clusters of version 9.1.0.210 or later.

4

dump-options

Backup parameter

Backup options supported during fine-grained backup. DWS supports permission and comment backup. This parameter is supported only by clusters of version 9.1.0 or later.

  • Permission: enable_handle_acl
  • Comment: enable_handle_comment

Do not back up permissions and comments.

parallel-process

Restoration parameter

Number of concurrent processes on each node during Roach backup. By default, the value is the number of primary DNs on the current node plus 1.

1

cpu-cores

Restoration parameter

Number of CPU cores that can be used when Roach starts multiple threads concurrently

Half of the number of CPU cores

logging-level

Restoration parameter

Log levels:

  • FATAL: Unrecoverable faults that cause the system suspension. This is the most severe level.
  • ERROR: Major errors.
  • WARNING: Exceptions. In this case, the system may continue to process tasks.
  • INFO: Notes.
  • DEBUG: Debugging details.
  • DEBUG2: Detailed debugging information, which is generally not displayed. This is the least severe level.

INFO

thread-count

Restoration parameter

Number of concurrent threads used when Roach starts multi-thread restoration of cold and hot tables and V3 tables. A high parameter value may block access to OBS. This parameter is supported only by clusters of version 9.1.0.210 or later.

4
Parent Topic: Backing Up and Restoring a DWS Cluster