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Tair (Redis® OSS-Compatible):Read/write splitting cluster instances (retired)

Last Updated:Nov 01, 2025

This topic describes the specifications of Redis Open-Source Edition read/write splitting cluster instances. The specifications include memory capacity, maximum connections, bandwidth, and queries per second (QPS) reference values.

Instance specifications

Note

The term '2 Shards' in an instance type name indicates that the instance has two data shards. For example, the 4 GB Read/write Splitting Instance (2 Shards, 1 Read Replica) instance type has two data shards, and each data shard contains one read replica.

Specification

InstanceClass (for API calls)

CPU cores

Shards

Read replicas per shard

Bandwidth (MB/s)

Maximum connections

QPS reference value

4 GB read/write splitting instance (2 shards, 1 read replica)

redis.logic.splitrw.sharding2g.2db.1rodb.4proxy.default

8

2

1

384

40,000

400,000

8 GB read/write splitting instance (2 shards, 1 read replica)

redis.logic.splitrw.sharding4g.2db.1rodb.4proxy.default

8

2

1

384

40,000

400,000

16 GB read/write splitting instance (2 shards, 1 read replica)

redis.logic.splitrw.sharding8g.2db.1rodb.8proxy.default

8

2

1

384

40,000

400,000

32 GB read/write splitting instance (8 shards, 1 read replica)

redis.logic.splitrw.sharding4g.8db.1rodb.16proxy.default

32

8

1

1,536

160,000

1,600,000

64 GB read/write splitting instance (16 shards, 1 read replica)

redis.logic.splitrw.sharding4g.16db.1rodb.32proxy.default

64

16

1

2,048

320,000

3,200,000

128 GB read/write splitting instance (16 shards, 1 read replica)

redis.logic.splitrw.sharding8g.16db.1rodb.32proxy.default

64

16

1

2,048

320,000

3,200,000

256 GB read/write splitting instance (32 shards, 1 read replica)

redis.logic.splitrw.sharding8g.32db.1rodb.64proxy.default

128

32

1

2,048

500,000

6,400,000

512 GB read/write splitting instance (32 shards, 1 read replica)

redis.logic.splitrw.sharding16g.32db.1rodb.64proxy.default

128

32

1

2,048

500,000

6,400,000

Notes about CPU cores

To ensure service stability, the system reserves a CPU core to process background tasks. In a cluster instance or a read/write splitting instance, the system reserves a CPU core for each shard or read replica to process background tasks.

Calculation rules for bandwidth values

  • Each bandwidth value in the preceding table represents the maximum bandwidth for an instance of the corresponding instance type, which is the combined bandwidth of all shards or nodes in the instance.

  • The bandwidth applies to the upstream and downstream bandwidths. For example, if the bandwidth of an instance is 80 Mbps (10 MB/s), the upstream and downstream bandwidths of the instance are both 80 Mbps (10 MB/s).

    Note

    If your instance has unexpected or scheduled traffic peaks, you can adjust the bandwidth of the instance. For more information, see Manually increase the bandwidth of an instance.

  • The bandwidth limits of Tair and Redis Open-Source Edition refer to the data transfer capacity of individual shards within their respective distributed systems. The limits are generally independent of the network connection types used by clients to connect to the shards.

For information about the FAQ about bandwidth, see FAQ about bandwidth.