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Tair (Redis® OSS-Compatible):Cluster edition - Dual-replica

Last Updated:Nov 01, 2025

This topic describes the instance types for dual-replica cluster instances of Redis Open-Source Edition. Specifications include memory capacity, maximum connections, bandwidth, and reference queries per second (QPS).

Instance types

In a cluster architecture, each data shard consists of one primary node and one replica node.

Instance types are available with the following numbers of shards: 2 shards, 4 shards, 8 shards, 16 shards, 32 shards, 64 shards, 128 shards, and 256 shards.

  • 2 shards

    Instances in this series have 2 shards and a total of 4 CPU cores (2 CPU cores per shard).

    Instance type name

    Instance type code (for API calls)

    Memory per shard (GB)

    Proxy mode

    Maximum connections

    Direct connection mode

    Maximum connections

    Total bandwidth

    Bandwidth per shard

    Reference QPS

    2 GB Cluster Edition (2 shards)

    redis.logic.sharding.1g.2db.0rodb.4proxy.default

    1

    240,000

    20,000

    768 Mbps (96 MB/s)

    384 Mbps (48 MB/s)

    200,000

    4 GB Cluster Edition (2 shards)

    redis.logic.sharding.2g.2db.0rodb.4proxy.default

    2

    240,000

    20,000

    1,536 Mbps (192 MB/s)

    768 Mbps (96 MB/s)

    200,000

    8 GB Cluster Edition (2 shards)

    redis.logic.sharding.4g.2db.0rodb.4proxy.default

    4

    240,000

    20,000

    1,536 Mbps (192 MB/s)

    768 Mbps (96 MB/s)

    200,000

    16 GB Cluster Edition (2 shards)

    redis.logic.sharding.8g.2db.0rodb.4proxy.default

    8

    240,000

    20,000

    1,536 Mbps (192 MB/s)

    768 Mbps (96 MB/s)

    200,000

    32 GB Cluster Edition (2 shards)

    redis.logic.sharding.16g.2db.0rodb.4proxy.default

    16

    240,000

    20,000

    1,536 Mbps (192 MB/s)

    768 Mbps (96 MB/s)

    200,000

  • 4 shards

    Instances in this series have 4 shards and a total of 8 CPU cores (2 CPU cores per shard).

    Instance type name

    Instance type code (for API calls)

    Memory per shard (GB)

    Proxy mode

    Maximum connections

    Direct connection mode

    Maximum connections

    Total bandwidth

    Bandwidth per shard

    Reference QPS

    4 GB Cluster Edition (4 shards)

    redis.logic.sharding.1g.4db.0rodb.4proxy.default

    1

    480,000

    40,000

    1,536 Mbps (192 MB/s)

    384 Mbps (48 MB/s)

    400,000

    8 GB Cluster Edition (4 shards)

    redis.logic.sharding.2g.4db.0rodb.4proxy.default

    2

    480,000

    40,000

    3,072 Mbps (384 MB/s)

    768 Mbps (96 MB/s)

    400,000

    16 GB Cluster Edition (4 shards)

    redis.logic.sharding.4g.4db.0rodb.4proxy.default

    4

    480,000

    40,000

    3,072 Mbps (384 MB/s)

    768 Mbps (96 MB/s)

    400,000

    24 GB Cluster Edition (4 shards)

    redis.logic.sharding.6g.4db.0rodb.4proxy.default

    6

    480,000

    40,000

    3,072 Mbps (384 MB/s)

    768 Mbps (96 MB/s)

    400,000

    32 GB Cluster Edition (4 shards)

    redis.logic.sharding.8g.4db.0rodb.4proxy.default

    8

    480,000

    40,000

    3,072 Mbps (384 MB/s)

    768 Mbps (96 MB/s)

    400,000

    64 GB Cluster Edition (4 shards)

    redis.logic.sharding.16g.4db.0rodb.4proxy.default

    16

    480,000

    40,000

    3,072 Mbps (384 MB/s)

    768 Mbps (96 MB/s)

    400,000

    128 GB Cluster Edition (4 shards)

    redis.logic.sharding.32g.4db.0rodb.8proxy.default

    32

    480,000

    40,000

    3,072 Mbps (384 MB/s)

    768 Mbps (96 MB/s)

    400,000

  • 8 shards

    Instances in this series have 8 shards and a total of 16 CPU cores (2 CPU cores per shard).

    Instance type name

    Instance type code (for API calls)

    Memory per shard (GB)

    Proxy mode

    Maximum connections

    Direct connection mode

    Maximum connections

    Total bandwidth

    Bandwidth per shard

    Reference QPS

    8 GB Cluster Edition (8 shards)

    redis.logic.sharding.1g.8db.0rodb.8proxy.default

    1

    500,000

    80,000

    3,072 Mbps (384 MB/s)

    384 Mbps (48 MB/s)

    800,000

    16 GB Cluster Edition (8 shards)

    redis.logic.sharding.2g.8db.0rodb.8proxy.default

    2

    500,000

    80,000

    6,144 Mbps (768 MB/s)

    768 Mbps (96 MB/s)

    800,000

    32 GB Cluster Edition (8 shards)

    redis.logic.sharding.4g.8db.0rodb.8proxy.default

    4

    500,000

    80,000

    6,144 Mbps (768 MB/s)

    768 Mbps (96 MB/s)

    800,000

    48 GB Cluster Edition (8 shards)

    redis.logic.sharding.6g.8db.0rodb.8proxy.default

    6

    500,000

    80,000

    6,144 Mbps (768 MB/s)

    768 Mbps (96 MB/s)

    800,000

    64 GB Cluster Edition (8 shards)

    redis.logic.sharding.8g.8db.0rodb.8proxy.default

    8

    500,000

    80,000

    6,144 Mbps (768 MB/s)

    768 Mbps (96 MB/s)

    800,000

    128 GB Cluster Edition (8 shards)

    redis.logic.sharding.16g.8db.0rodb.8proxy.default

    16

    500,000

    80,000

    6,144 Mbps (768 MB/s)

    768 Mbps (96 MB/s)

    800,000

  • 16 shards

    Instances in this series have 16 shards and a total of 32 CPU cores (2 CPU cores per shard).

    Instance type name

    Instance type code (for API calls)

    Memory per shard (GB)

    Proxy mode

    Maximum connections

    Direct connection mode

    Maximum connections

    Total bandwidth

    Bandwidth per shard

    Reference QPS

    16 GB Cluster Edition (16 shards)

    redis.logic.sharding.1g.16db.0rodb.16proxy.default

    1

    500,000

    160,000

    6,144 Mbps (768 MB/s)

    384 Mbps (48 MB/s)

    1,600,000

    32 GB Cluster Edition (16 shards)

    redis.logic.sharding.2g.16db.0rodb.16proxy.default

    2

    500,000

    160,000

    12,288 Mbps (1,536 MB/s)

    768 Mbps (96 MB/s)

    1,600,000

    64 GB Cluster Edition (16 shards)

    redis.logic.sharding.4g.16db.0rodb.16proxy.default

    4

    500,000

    160,000

    12,288 Mbps (1,536 MB/s)

    768 Mbps (96 MB/s)

    1,600,000

    96 GB Cluster Edition (16 shards)

    redis.logic.sharding.6g.16db.0rodb.16proxy.default

    6

    500,000

    160,000

    12,288 Mbps (1,536 MB/s)

    768 Mbps (96 MB/s)

    1,600,000

    128 GB Cluster Edition (16 shards)

    redis.logic.sharding.8g.16db.0rodb.16proxy.default

    8

    500,000

    160,000

    12,288 Mbps (1,536 MB/s)

    768 Mbps (96 MB/s)

    1,600,000

    256 GB Cluster Edition (16 shards)

    redis.logic.sharding.16g.16db.0rodb.16proxy.default

    16

    500,000

    160,000

    12,288 Mbps (1,536 MB/s)

    768 Mbps (96 MB/s)

    1,600,000

  • 32 shards

    Instances in this series have 32 shards and a total of 64 CPU cores (2 CPU cores per shard).

    Instance type name

    Instance type code (for API calls)

    Memory per shard (GB)

    Proxy mode

    Maximum connections

    Direct connection mode

    Maximum connections

    Total bandwidth

    Bandwidth per shard

    Reference QPS

    64 GB Cluster Edition (32 shards)

    redis.logic.sharding.2g.32db.0rodb.32proxy.default

    2

    500,000

    320,000

    16,384 Mbps (2,048 MB/s)

    768 Mbps (96 MB/s)

    3,200,000

    128 GB Cluster Edition (32 shards)

    redis.logic.sharding.4g.32db.0rodb.32proxy.default

    4

    500,000

    320,000

    16,384 Mbps (2,048 MB/s)

    768 Mbps (96 MB/s)

    3,200,000

    192 GB Cluster Edition (32 shards)

    redis.logic.sharding.6g.32db.0rodb.32proxy.default

    6

    500,000

    320,000

    16,384 Mbps (2,048 MB/s)

    768 Mbps (96 MB/s)

    3,200,000

    256 GB Cluster Edition (32 shards)

    redis.logic.sharding.8g.32db.0rodb.32proxy.default

    8

    500,000

    320,000

    16,384 Mbps (2,048 MB/s)

    768 Mbps (96 MB/s)

    3,200,000

    512 GB Cluster Edition (32 shards)

    redis.logic.sharding.16g.32db.0rodb.32proxy.default

    16

    500,000

    320,000

    16,384 Mbps (2,048 MB/s)

    768 Mbps (96 MB/s)

    3,200,000

  • 64 shards

    Instances in this series have 64 shards and a total of 128 CPU cores (2 CPU cores per shard).

    Instance type name

    Instance type code (for API calls)

    Memory per shard (GB)

    Proxy mode

    Maximum connections

    direct connection mode

    Maximum connections

    Total bandwidth

    Bandwidth per shard

    Reference QPS

    128 GB Cluster Edition (64 shards)

    redis.logic.sharding.2g.64db.0rodb.64proxy.default

    2

    500,000

    640,000

    16,384 Mbps (2,048 MB/s)

    768 Mbps (96 MB/s)

    6,400,000

    256 GB Cluster Edition (64 shards)

    redis.logic.sharding.4g.64db.0rodb.64proxy.default

    4

    500,000

    640,000

    16,384 Mbps (2,048 MB/s)

    768 Mbps (96 MB/s)

    6,400,000

    512 GB Cluster Edition (64 shards)

    redis.logic.sharding.8g.64db.0rodb.64proxy.default

    8

    500,000

    640,000

    16,384 Mbps (2,048 MB/s)

    768 Mbps (96 MB/s)

    6,400,000

  • 128 shards

    Instances in this series have 128 shards and a total of 256 CPU cores (2 CPU cores per shard).

    Instance type name

    Instance type code (for API calls)

    Memory per shard (GB)

    Proxy mode

    Maximum connections

    Direct connection mode

    Maximum connections

    Total bandwidth

    Bandwidth per shard

    Reference QPS

    512 GB Cluster Edition (128 shards)

    redis.logic.sharding.4g.128db.0rodb.128proxy.default

    4

    500,000

    1,280,000

    16,384 Mbps (2,048 MB/s)

    768 Mbps (96 MB/s)

    12,800,000

  • 256 shards

    Instances in this series have 256 shards and a total of 512 CPU cores (2 CPU cores per shard).

    Instance type name

    Instance type code (for API calls)

    Memory per shard (GB)

    Proxy mode

    Maximum connections

    direct connection mode

    Maximum connections

    Total bandwidth

    Bandwidth per shard

    Reference QPS

    1024 GB Cluster Edition (256 shards)

    redis.logic.sharding.4g.256db.0rodb.256proxy.default

    4

    500,000

    2,560,000

    16,384 Mbps (2,048 MB/s)

    768 Mbps (96 MB/s)

    25,600,000

    2048 GB Cluster Edition (256 shards)

    redis.logic.sharding.8g.256db.0rodb.256proxy.default

    8

    500,000

    2,560,000

    16,384 Mbps (2,048 MB/s)

    768 Mbps (96 MB/s)

    25,600,000

    4096 GB Cluster Edition (256 shards)

    redis.logic.sharding.16g.256db.0rodb.256proxy.default

    16

    500,000

    2,560,000

    16,384 Mbps (2,048 MB/s)

    768 Mbps (96 MB/s)

    25,600,000

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.

Bandwidth calculation rules

  • The total bandwidth in the tables represents the bandwidth for the entire instance, which is the sum of the bandwidth of all its shards or nodes. The bandwidth limit for each shard is as follows:

    • For Redis Open-Source Edition: The maximum bandwidth per shard is 384 Mbps (48 MB/s) if the shard has 1 GB of memory or less. The maximum bandwidth is 768 Mbps (96 MB/s) if the shard has more than 1 GB of memory.

    • For Tair: The maximum bandwidth per shard is 768 Mbps (96 MB/s).

  • For a cluster instance that uses the default database proxy endpoint, the bandwidth is capped at 16,384 Mbps (2,048 MB/s). The bandwidth does not increase beyond this limit, even if you add more shards.

    To handle high network traffic, you can enable direct connection mode. For more information, see Enable direct connection mode. This feature is available only for cluster instances. After you enable direct connection mode:

    • Maximum connections: The total is calculated as (Maximum connections per shard) × (Number of shards). For Redis Open-Source Edition, the maximum is 10,000 connections per shard. For Tair, the maximum is 30,000 connections per shard.

    • Total bandwidth limit: The limit is calculated as (Maximum bandwidth per shard) × (Number of shards). For example, consider a 128-shard cluster instance where each shard has more than 1 GB of memory and a maximum bandwidth of 96 MB/s. After you enable direct connection mode, the total bandwidth becomes 12,288 MB/s.

  • The specified bandwidth applies to both upstream and downstream traffic. For example, if an instance type has a bandwidth of 384 Mbps (48 MB/s), both its upstream and downstream bandwidth are 384 Mbps (48 MB/s).

    Note

    If your instance experiences burst or planned traffic peaks, you can adjust the instance bandwidth as needed. For more information, see Manually increase instance bandwidth.

  • The bandwidth listed in the tables is the internal bandwidth of the Redis instance. Public bandwidth depends on the internal bandwidth and is also limited by the network connection between the instance and the client. You can use an internal connection to eliminate public network overhead and maximize bandwidth performance.

Maximum connections details

  • In proxy mode, the maximum number of connections for an instance is 500,000. This number does not increase beyond this limit, even if you add more shards or nodes.

    Note

    For instances created before March 1, 2020, the maximum number of connections in proxy mode is 200,000.

  • In direct connection mode, the maximum number of connections per shard is 10,000. The maximum number of connections for the instance is calculated as (Number of shards) × 10,000.

FAQ

  • Q: Why is my instance's actual bandwidth different from what is described in this document?

    A: The bandwidth for some instance types may change due to product upgrades. If your instance's bandwidth is different from what is described here, you can change the instance configuration to update it. You can select your current instance type as the target configuration, and the cost will remain the same.

  • Q: Why do write operations fail on my cluster instance even though its memory is not full?

    A: Redis uses a hash algorithm to distribute keys evenly across shards. However, the presence of large keys in a cluster instance can lead to skewed resource distribution. In severe cases, the shard containing the large keys can become full, causing some write requests to fail.

    You can use the Performance monitoring feature to view and optimize the performance metrics of each shard. For more information, see How to view performance metrics such as memory usage of child nodes in a Redis cluster.

  • Q: In an instance type code such as redis.logic.sharding.1g.8db.0rodb.8proxy.default, does 8proxy indicate that there are eight proxy nodes?

    A: No. The 8proxy part of the instance type code does not represent the number of proxy nodes. You do not need to track the specific number of nodes because the proxy computing power and bandwidth are guaranteed to meet the specifications listed in the tables.