This topic describes the specifications of DRAM-based cluster instances of ApsaraDB for Redis Enhanced Edition (Tair). These specifications include the memory capacity, maximum number of connections, maximum bandwidth, and queries per second (QPS) reference value.
Instance specifications
Instance specification types: 2 shards, 4 shards, 8 shards, 16 shards, 32 shards, 64 shards, 128 shards, and 256 shards.
2 shards
For this series of instance specifications, the number of shards is 2, the number of CPU cores is 12 (6 cores per shard), and the maximum number of new connections per second is 50,000.
Specification
InstanceClass value (used in API operations)
Memory per shard (GB)
Proxy mode: Maximum connections
Direct connection mode: Maximum connections
Total bandwidth (Mbit/s)
Bandwidth per shard (Mbit/s)
QPS reference value
2 GB cluster instance (2 shards)
redis.amber.logic.sharding.1g.2db.0rodb.6proxy.multithread
1
480,000
60,000
192
96
480,000
4 GB cluster instance (2 shards)
redis.amber.logic.sharding.2g.2db.0rodb.6proxy.multithread
2
480,000
60,000
192
96
480,000
4 shards
For this series of instance specifications, the number of shards is 4, the number of CPU cores is 24 (6 cores per shard), and the maximum number of new connections per second is 50,000.
Specification
InstanceClass value (used in API operations)
Memory per shard (GB)
Proxy mode: Maximum connections
Direct connection mode: Maximum connections
Total bandwidth (Mbit/s)
Bandwidth per shard (Mbit/s)
QPS reference value
8 GB cluster instance (4 shards)
redis.amber.logic.sharding.2g.4db.0rodb.12proxy.multithread
2
500,000
120,000
384
96
960,000
8 shards
For this series of instance specifications, the number of shards is 8, the number of CPU cores is 48 (6 cores per shard), and the maximum number of new connections per second is 50,000.
Specification
InstanceClass value (used in API operations)
Memory per shard (GB)
Proxy mode: Maximum connections
Direct connection mode: Maximum connections
Total bandwidth (Mbit/s)
Bandwidth per shard (Mbit/s)
QPS reference value
16 GB cluster instance (8 shards)
redis.amber.logic.sharding.2g.8db.0rodb.24proxy.multithread
2
500,000
240,000
768
96
1,920,000
32 GB cluster instance (8 shards)
redis.amber.logic.sharding.4g.8db.0rodb.24proxy.multithread
4
500,000
240,000
768
96
1,920,000
64 GB cluster instance (8 shards)
redis.amber.logic.sharding.8g.8db.0rodb.24proxy.multithread
8
500,000
240,000
768
96
1,920,000
128 GB cluster instance (8 shards)
redis.amber.logic.sharding.16g.8db.0rodb.24proxy.multithread
16
500,000
240,000
768
96
1,920,000
16 shards
For this series of instance specifications, the number of shards is 16, the number of CPU cores is 96 (6 cores per shard), and the maximum number of new connections per second is 50,000.
Specification
InstanceClass value (used in API operations)
Memory per shard (GB)
Proxy mode: Maximum connections
Direct connection mode: Maximum connections
Total bandwidth (Mbit/s)
Bandwidth per shard (Mbit/s)
QPS reference value
32 GB cluster instance (16 shards)
redis.amber.logic.sharding.2g.16db.0rodb.48proxy.multithread
2
500,000
480,000
1,536
96
3,840,000
128 GB cluster instance (16 shards)
redis.amber.logic.sharding.8g.16db.0rodb.48proxy.multithread
8
500,000
480,000
1,536
96
3,840,000
256 GB cluster instance (16 shards)
redis.amber.logic.sharding.16g.16db.0rodb.48proxy.multithread
16
500,000
480,000
1,536
96
3,840,000
32 shards
For this series of instance specifications, the number of shards is 32, the number of CPU cores is 192 (6 cores per shard), and the maximum number of new connections per second is 50,000.
Specification
InstanceClass value (used in API operations)
Memory per shard (GB)
Proxy mode: Maximum connections
Direct connection mode: Maximum connections
Total bandwidth (Mbit/s)
Bandwidth per shard (Mbit/s)
QPS reference value
64 GB cluster instance (32 shards)
redis.amber.logic.sharding.2g.32db.0rodb.96proxy.multithread
2
500,000
960,000
2,048
96
7,680,000
512 GB cluster instance (32 shards)
redis.amber.logic.sharding.16g.32db.0rodb.96proxy.multithread
16
500,000
960,000
2,048
96
7,680,000
64 shards
For this series of instance specifications, the number of shards is 64, the number of CPU cores is 384 (6 cores per shard), and the maximum number of new connections per second is 50,000.
Specification
InstanceClass value (used in API operations)
Memory per shard (GB)
Proxy mode: Maximum connections
Direct connection mode: Maximum connections
Total bandwidth (Mbit/s)
Bandwidth per shard (Mbit/s)
QPS reference value
128 GB cluster instance (64 shards)
redis.amber.logic.sharding.2g.64db.0rodb.192proxy.multithread
2
500,000
1,920,000
2,048
96
15,360,000
256 GB cluster instance (64 shards)
redis.amber.logic.sharding.4g.64db.0rodb.192proxy.multithread
4
500,000
1,920,000
2,048
96
15,360,000
1024 GB cluster instance (64 shards)
redis.amber.logic.sharding.16g.64db.0rodb.192proxy.multithread
16
500,000
1,920,000
2,048
96
15,360,000
128 shards
For this series of instance specifications, the number of shards is 128, the number of CPU cores is 768 (6 cores per shard), and the maximum number of new connections per second is 50,000.
Specification
InstanceClass value (used in API operations)
Memory per shard (GB)
Proxy mode: Maximum connections
Direct connection mode: Maximum connections
Total bandwidth (Mbit/s)
Bandwidth per shard (Mbit/s)
QPS reference value
2048 GB cluster instance (128 shards)
redis.amber.logic.sharding.16g.128db.0rodb.384proxy.multithread
16
500,000
3,840,000
2,048
96
30,720,000
256 shards
For this series of instance specifications, the number of shards is 256, the number of CPU cores is 1,536 (6 cores per shard), and the maximum number of new connections per second is 50,000.
Specification
InstanceClass value (used in API operations)
Memory per shard (GB)
Proxy mode: Maximum connections
Direct connection mode: Maximum connections
Total bandwidth (Mbit/s)
Bandwidth per shard (Mbit/s)
QPS reference value
4096 GB cluster instance (256 shards)
redis.amber.logic.sharding.16g.256db.0rodb.768proxy.multithread
16
500,000
7,680,000
2,048
96
61,440,000
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 tables 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 maximum bandwidth for each shard is 96 Mbit/s.
If the default proxy endpoint is used by a cluster instance, the maximum bandwidth for the cluster instance is 2,048 Mbit/s. After the upper limit is reached, the bandwidth cannot be increased even if you add more shards to the cluster instance.
NoteTo handle network traffic peaks, you can enable the direct connection mode. For more information, see Enable the direct connection mode. The direct connection mode is applicable only to cluster instances. In direct connection mode, the maximum bandwidth of the instance is equal to the maximum bandwidth of a single shard multiplied by the number of shards. For example, if a cluster instance contains 128 shards and each shard is allocated a memory of more than 1 GB, the maximum bandwidth of the instance is 12,288 Mbit/s.
The bandwidth value applies to the upstream and downstream bandwidths. For example, if the bandwidth of an instance is 10 Mbit/s, the upstream and downstream bandwidths of the instance are both 10 Mbit/s.
NoteIf your instance may experience an unexpected or anticipated surge in traffic, you can adjust the bandwidth of the instance on demand. For more information, see Manually increase the bandwidth of an instance.
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 |
|
Maximum number of new connections per second | The maximum number of new connections per second refers to the number of connections that can be established per second.
|
FAQ
Why is the actual bandwidth of my instance different from the bandwidth described in this topic?
The bandwidths of specific instance types may be adjusted after the service is upgraded. If the actual bandwidth of your instance is different from that described in this topic, you can change the configurations of your instance by selecting the same instance type to update the bandwidth. The price of your instance remains unchanged after the configuration change. For more information, see Change the configurations of an instance.
Why am I unable to write data to a cluster instance when instance memory is not exhausted?
This is because the instance contains exhausted shards. Redis uses the hash algorithm to evenly write data to different shards. If the instance contains large keys, resources are unevenly distributed in the instance and the shards that house these large keys may even be exhausted. In this case, specific write requests to the instance may fail.
You can use the Performance Monitor feature to check and optimize the performance of each shard. For more information, see View the performance metrics of nodes in a Tair cluster instance.