This topic describes the specifications of ApsaraDB for Redis Community Edition standard instances that use cloud disks. These specifications include the memory capacity, maximum number of connections to each instance, maximum bandwidth, and queries per second (QPS) reference value.
|Standard||The overall performance of standard instances is as described in the instance types table.|
|Cluster||The overall performance of cluster instances is calculated by using the following
formula: Overall performance of an instance = Number of shards in the instance × Performance
of each shard specified by instance specifications. For example, a cluster instance
has four shards of the redis.shard.small.ce type, which is the second instance type
in the Instance types table. Each shard provides the following performance:
The cluster instance provides the following performance:
- Enhanced SSDs (ESSDs) are used only to store system operating data, such as logs and backup data. ESSDs are not used as the media to read or write data. For more information about ESSDs, see ESSDs.
- You can change the number of shards in a cluster instance that uses cloud disks. Such a cluster instance can contain 2 to 256 shards with the same specifications. For each configuration change, up to 64 shards can be added or removed. For more information, see Adjust the number of shards for an ApsaraDB for Redis instance.
|Instance type||InstanceClass value (used in API operations)||Number of cores||Memory (GB)||ESSDs (GB)||Maximum bandwidth (MB/s)||Maximum number of connections||QPS reference value|
|256 MB instance that uses shared vCPUs||redis.shard.micro.ce||2||0.25||1.25||24||10,000||100,000|
|1 GB instance that uses shared vCPUs||redis.shard.small.ce||2||1||5||24||10,000||100,000|
|2 GB instance that uses shared vCPUs||redis.shard.mid.ce||2||2||10||24||10,000||100,000|
|4 GB instance that uses shared vCPUs||redis.shard.large.ce||2||4||20||32||10,000||100,000|
|8 GB instance that uses shared vCPUs||redis.shard.xlarge.ce||2||8||40||40||10,000||100,000|
|16 GB instance that uses shared vCPUs||redis.shard.2xlarge.ce||2||16||80||80||10,000||100,000|
|24 GB instance that uses shared vCPUs||redis.shard.3xlarge.ce||2||24||120||96||10,000||100,000|
|32 GB instance that uses shared vCPUs||redis.shard.4xlarge.ce||2||32||160||96||10,000||100,000|
|64 GB instance that uses shared vCPUs||redis.shard.8xlarge.ce||2||64||320||96||10,000||100,000|
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
- 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.
- The bandwidth value in the preceding tables is the internal bandwidth of ApsaraDB for Redis instances. The Internet bandwidth is determined by the internal bandwidth and is limited by the bandwidth of the connection between an ApsaraDB for Redis instance and a client. To ensure higher security and lower network latency, we recommend that you connect to an ApsaraDB for Redis instance over a virtual private cloud (VPC). For more information about VPCs, see What is a VPC?
Calculation rules for connections
The following example shows how the maximum number of new connections per second affects the maximum number of connections at a specific second: The maximum number of new connections per second of an instance is 10,000. The maximum number of connections of the instance is 50,000. The actual number of connections at the Nth second after the instance starts to run is 12,000. Then, at the (N+1)th second, the maximum number of connections is 22,000, which is calculated by using the following formula: 12,000 + 10,000.
Q: Why is the actual bandwidth of my instance different from that described in this topic?
A: The bandwidths of specific instance types may be adjusted after the service is upgraded. If the bandwidth of your instance is different from that described in this topic, change your instance specifications to update the bandwidth. Make sure that you select the same instance type when you change the specifications. For more information, see Change the configurations of an instance.