This topic describes the specifications of DRAM-based standard instances of Tair. These specifications include the memory capacity, maximum number of connections, maximum bandwidth, and queries per second (QPS) reference value.
Instance specifications
Specification | InstanceClass value (used in API operations) | CPU cores | I/O threads | Memory (GB) | Bandwidth (Mbit/s) | Maximum connections | QPS reference value |
1 GB master-replica instance | redis.amber.master.small.multithread | 6 | 4 | 1 | 96 | 30,000 | 240,000 |
2 GB master-replica instance | redis.amber.master.mid.multithread | 6 | 4 | 2 | 96 | 30,000 | 240,000 |
4 GB master-replica instance | redis.amber.master.stand.multithread | 6 | 4 | 4 | 96 | 40,000 | 240,000 |
8 GB master-replica instance | redis.amber.master.large.multithread | 6 | 4 | 8 | 96 | 40,000 | 240,000 |
16 GB master-replica instance | redis.amber.master.2xlarge.multithread | 6 | 4 | 16 | 96 | 40,000 | 240,000 |
32 GB master-replica instance | redis.amber.master.4xlarge.multithread | 6 | 4 | 32 | 96 | 50,000 | 240,000 |
64 GB master-replica instance | redis.amber.master.8xlarge.multithread | 6 | 4 | 64 | 96 | 50,000 | 240,000 |
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 bandwidth value applies 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 encounters unexpected or scheduled traffic peaks, you can adjust the bandwidth of the instance. 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.
FAQ
Why is the maximum number of connections to my instance different from that described in this topic?
The maximum number of connections of specific instance types may be adjusted after the service is upgraded. If the maximum number of connections to your instance is different from that described in this topic, change the configurations of your instance to update the bandwidth. Make sure that you select the same instance type when you change the configurations. For more information, see Change the configurations of an instance.