doc-exports/docs/dds/umn/dds_01_0002.html
Ru, Li Yi cd74617674 dds_umn_20240415
Reviewed-by: Wagner, Fabian <fabian.wagner@t-systems.com>
Co-authored-by: Ru, Li Yi <liyiru7@huawei.com>
Co-committed-by: Ru, Li Yi <liyiru7@huawei.com>
2024-04-16 08:01:15 +00:00

2.3 KiB

Cluster

Each DDS cluster consists of a config node, and multiple dds mongos and shard nodes. The following diagram shows the node relationships.

Figure 1 Diagram of node relationships

dds mongos

A dds mongos is a router for reading and writing data, providing a unified interface for accessing DB instances.

  • Each DB instance has 2 to 32 dds mongos. You can specify the quantity.
  • A dds mongos reads configuration settings from configs and allocates read and write requests to shards. You can connect to a dds mongos directly.

config

A config stores configuration settings for DB instances and consists of one replica set.

  • The availability of a config is the prerequisite to deploying a DB instance or modifying the instance information.
  • You cannot connect to a config directly.

shard

In the cluster instance, shards are used to store user data.

  • Each cluster instance has 2 to 32 shards. You can specify the quantity.
  • Each shard is deployed as a replica set to ensure data redundancy and high reliability.
  • You cannot connect to a shard directly.