This topic describes the specifications of read/write splitting instances of ApsaraDB for Redis Community Edition. The specifications include the memory capacity, maximum number of connections, maximum bandwidth, and queries per second (QPS) reference value.
Instance specifications
The following table describes the instance specifications that involve only one shard. For example, 1 GB read/write splitting instance (1 shard, 3 read replicas) indicates that the instance has one shard that contains three read replicas.
Specification | InstanceClass value (used in API operations) | CPU cores | Read replicas | Bandwidth (Mbit/s) | Maximum number of new connections per second | Maximum connections | QPS reference value |
1 GB read/write splitting instance (1 shard, 1 read replica) | redis.logic.splitrw.small.1db.1rodb.4proxy.default | 4 | 1 | 96 | 20,000 | 20,000 | 200,000 |
1 GB read/write splitting instance (1 shard, 3 read replicas) | redis.logic.splitrw.small.1db.3rodb.4proxy.default | 8 | 3 | 192 | 40,000 | 40,000 | 400,000 |
1 GB read/write splitting instance (1 shard, 5 read replicas) | redis.logic.splitrw.small.1db.5rodb.6proxy.default | 12 | 5 | 288 | 50,000 | 60,000 | 600,000 |
2 GB read/write splitting instance (1 shard, 1 read replica) | redis.logic.splitrw.mid.1db.1rodb.4proxy.default | 4 | 1 | 192 | 20,000 | 20,000 | 200,000 |
2 GB read/write splitting instance (1 shard, 3 read replicas) | redis.logic.splitrw.mid.1db.3rodb.4proxy.default | 8 | 3 | 384 | 40,000 | 40,000 | 400,000 |
2 GB read/write splitting instance (1 shard, 5 read replicas) | redis.logic.splitrw.mid.1db.5rodb.6proxy.default | 12 | 5 | 576 | 50,000 | 60,000 | 600,000 |
4 GB read/write splitting instance (1 shard, 1 read replica) | redis.logic.splitrw.stand.1db.1rodb.4proxy.default | 4 | 1 | 192 | 20,000 | 20,000 | 200,000 |
4 GB read/write splitting instance (1 shard, 3 read replicas) | redis.logic.splitrw.stand.1db.3rodb.4proxy.default | 8 | 3 | 384 | 40,000 | 40,000 | 400,000 |
4 GB read/write splitting instance (1 shard, 5 read replicas) | redis.logic.splitrw.stand.1db.5rodb.6proxy.default | 12 | 5 | 576 | 50,000 | 60,000 | 600,000 |
8 GB read/write splitting instance (1 shard, 1 read replica) | redis.logic.splitrw.large.1db.1rodb.4proxy.default | 4 | 1 | 192 | 20,000 | 20,000 | 200,000 |
8 GB read/write splitting instance (1 shard, 3 read replicas) | redis.logic.splitrw.large.1db.3rodb.4proxy.default | 8 | 3 | 384 | 40,000 | 40,000 | 400,000 |
8 GB read/write splitting instance (1 shard, 5 read replicas) | redis.logic.splitrw.large.1db.5rodb.6proxy.default | 12 | 5 | 576 | 50,000 | 60,000 | 600,000 |
16 GB read/write splitting instance (1 shard, 1 read replica) | redis.logic.splitrw.2xlarge.1db.1rodb.4proxy.default | 4 | 1 | 192 | 20,000 | 20,000 | 200,000 |
16 GB read/write splitting instance (1 shard, 3 read replicas) | redis.logic.splitrw.2xlarge.1db.3rodb.4proxy.default | 8 | 3 | 384 | 40,000 | 40,000 | 400,000 |
16 GB read/write splitting instance (1 shard, 5 read replicas) | redis.logic.splitrw.2xlarge.1db.5rodb.6proxy.default | 12 | 5 | 576 | 50,000 | 60,000 | 600,000 |
32 GB read/write splitting instance (1 shard, 1 read replica) | redis.logic.splitrw.4xlarge.1db.1rodb.4proxy.default | 4 | 1 | 192 | 20,000 | 20,000 | 200,000 |
32 GB read/write splitting instance (1 shard, 3 read replicas) | redis.logic.splitrw.4xlarge.1db.3rodb.4proxy.default | 8 | 3 | 384 | 40,000 | 40,000 | 400,000 |
32 GB read/write splitting instance (1 shard, 5 read replicas) | redis.logic.splitrw.4xlarge.1db.5rodb.6proxy.default | 12 | 5 | 576 | 50,000 | 60,000 | 600,000 |
64 GB read/write splitting instance (1 shard, 1 read replica) | redis.logic.splitrw.8xlarge.1db.1rodb.4proxy.default | 4 | 1 | 192 | 20,000 | 20,000 | 200,000 |
64 GB read/write splitting instance (1 shard, 3 read replicas) | redis.logic.splitrw.8xlarge.1db.3rodb.4proxy.default | 8 | 3 | 384 | 40,000 | 40,000 | 400,000 |
64 GB read/write splitting instance (1 shard, 5 read replicas) | redis.logic.splitrw.8xlarge.1db.5rodb.6proxy.default | 12 | 5 | 576 | 50,000 | 60,000 | 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 data shard or each 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 total bandwidth for a read/write splitting instance is 2,048 Mbit/s. After the upper limit is reached, the bandwidth cannot be increased even if you add more shards or nodes to the read/write splitting instance.
The bandwidth value is applicable to the upstream and downstream bandwidths. For example, if the bandwidth of an instance is 96 Mbit/s, the upstream and downstream bandwidths of the instance are both 96 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
The maximum number of new connections per second refers to the maximum number of connections that can be established per second. For example, the maximum number of new connections to an instance per second is 10,000, the maximum allowed number of connections to the instance is 50,000, and the actual number of connections at the Nth second after the instance starts to run is 12,000. In this case, the maximum number of connections at the (N+1)th second is 22,000. This value is calculated by using the following formula: 12,000 + 10,000.