Specifications of Tair ESSD/SSD-based instances - Tair (Redis® OSS-Compatible)

This topic describes the specifications of Tair (Enterprise Edition) ESSD/SSD-based instances. The specifications include the memory capacity, maximum number of connections, and maximum bandwidth.

Instance specifications

The following tables list the specifications of individual shards.

The overall performance of a standard instance is determined by the specifications of the shards in the instance.
The overall performance of a cluster instance can be estimated by multiplying the performance of a single shard by the total number of shards in the instance.
Note
- Starting May 8, 2024, the maximum number of connections to each shard of an ESSD/SSD-based instance is increased to 60,000. This increase applies to both newly created and upgraded instances.
- Instances that can be created in different regions and zones are subject to actual inventory.

Shard specifications of ESSD-based instances

ESSD-based instances support only the standard architecture.

Specification type	InstanceClass value (used in API operations)	CPU cores	Memory (GB)	Storage performance level and capacity range (GB)	Maximum connections	Bandwidth (Mbit/s)
4C - 16GB	tair.essd.standard.xlarge	4	16	PL1: 20 to 80	60,000	187.5
8C - 32GB	tair.essd.standard.2xlarge	8	32	PL1: 60 to 230 PL2: 470 to 750	60,000	250
16C - 64GB	tair.essd.standard.4xlarge	16	64	PL1: 60 to 460 PL2: 470 to 1,230 PL3: 1,270 to 2,160	60,000	375
32C - 96GB	tair.essd.standard.8xlarge	32	128	PL2: 470 to 2,160 PL3: 1,270 to 4,320	60,000	625
52C - 192GB	tair.essd.standard.13xlarge	52	192	PL2: 470 to 3,090 PL3: 1,270 to 6,150	60,000	1,000

Note

Enterprise SSDs at performance level 3 (PL3 ESSDs) perform better than PL2 and PL1 ESSDs. For more information, see ESSDs.

Shard specifications of SSD-based standard instances and cluster instances in direct connection mode

The following specifications are applicable to SSD-based standard instances and cluster instances in direct connection mode.

Specification type	InstanceClass value (used in API operations)	CPU cores	Memory (GB)	Storage performance level and capacity range (GB)	Maximum connections	Bandwidth (Mbit/s)
4C-32GB	tair.localssd.c1m8.xlarge	4	32	640	60,000	187.5
8C-32GB	tair.localssd.c1m4.2xlarge	8	32	320	60,000	375
8C-64GB	tair.localssd.c1m8.2xlarge	8	64	1,280	60,000	312.5
16C-64GB	tair.localssd.c1m4.4xlarge	16	64	640	60,000	625
32C-128GB	tair.localssd.c1m4.8xlarge	32	128	1,280	60,000	1,500

Shard specifications of SSD-based cluster instances in proxy mode

The following specifications are applicable to SSD-based cluster instances in proxy mode.

Specification type	InstanceClass value (used in API operations)	CPU cores	Memory (GB)	Storage performance level and capacity range (GB)	Maximum connections	Bandwidth (Mbit/s)
4C-32GB	tair.localssd.c1m8.with.proxy.xlarge	4	32	640	60,000	187.5
8C-32GB	tair.localssd.c1m4.with.proxy.2xlarge	8	32	320	60,000	375
8C-64GB	tair.localssd.c1m8.with.proxy.2xlarge	8	64	1,280	60,000	312.5
16C-64GB	tair.localssd.c1m4.with.proxy.4xlarge	16	64	640	60,000	625
32C-128GB	tair.localssd.c1m4.with.proxy.8xlarge	32	128	1,280	60,000	1,500

Performance description

Architecture

Performance description

Standard architecture

The overall performance of standard instances is the same as that described in the preceding instance specification tables.

Cluster architecture in direct connection mode

Cluster architecture in proxy mode

Overall performance of an instance = Performance of a shard × Number of shards.

Note

When a cluster instance that runs in proxy mode is accessed, the maximum bandwidth is 2,048 Mbit/s, the maximum total QPS is 10,000,000, and the maximum number of connections is 500,000.

For example, an instance that contains four shards of the tair.localssd.c1m4.with.proxy.2xlarge type has the following specifications:

Number of CPU cores: 8
Memory: 32 GB
SSD capacity: 320 GB
Number of connections: 60,000
Bandwidth: 375 Mbit/s

In this case, the instance provides the following performance:

Number of CPU cores: 32
Memory: 128 GB
SSD capacity: 1,280 GB
Number of connections: 240,000
Bandwidth: 1,500 Mbit/s

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 description

Each bandwidth value in the preceding tables represents the maximum bandwidth of a single shard. The total bandwidth of a cluster or read/write splitting instance is the combined bandwidth of all shards in the instance.
The maximum bandwidth of a cluster instance in proxy mode is 2,048 Mbit/s. After the upper limit is reached, the bandwidth cannot be increased even if you add more shards to the instance. Cluster instances in direct connection mode have no limits on the overall bandwidth.
The bandwidth applies to the upstream and downstream bandwidths. For example, if the overall bandwidth of an instance is 375 Mbit/s, the upstream and downstream bandwidths of the instance are both 375 Mbit/s.
The bandwidth limits of Tair and Redis 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.

Calculation rules for connections

Item	Description
Maximum number of connections	Proxy mode: 500,000. If the upper limit of 500,000 connections is reached, subsequent connections cannot be established even if you add more shards. Direct connection mode: Maximum number of connections to an instance = Maximum number of connections to a shard × Number of shards.