This topic describes the specifications of read/write splitting cluster instances of ApsaraDB for Redis Community Edition. These specifications include the memory capacity, maximum number of concurrent connections to each instance, maximum bandwidth, and QPS reference value for these instances.

Instance types

Note The following table describes the instance types that contain two shards. For example, 4 GB read/write splitting instance (2 master nodes, 1 read replica) indicates that the instance has two shards. Each shard contains one read replica.
Instance type InstanceClass (used in API operations) Number of shards Number of read replicas per shard Bandwidth (Mbit/s) Maximum number of new connections per second Maximum number of connections QPS reference value
4 GB read/write splitting instance (2 master nodes, 1 read replica) redis.logic.splitrw.sharding2g.2db.1rodb.4proxy.default 2 1 384 50,000 40,000 400,000
8 GB read/write splitting instance (2 master nodes, 1 read replica) redis.logic.splitrw.sharding4g.2db.1rodb.4proxy.default 2 1 384 50,000 40,000 400,000
16 GB read/write splitting instance (2 master nodes, 1 read replica) redis.logic.splitrw.sharding8g.2db.1rodb.8proxy.default 2 1 384 50,000 40,000 400,000
32 GB read/write splitting instance (8 master nodes, 1 read replica) redis.logic.splitrw.sharding4g.8db.1rodb.16proxy.default 8 1 1,536 50,000 160,000 1,600,000
64 GB read/write splitting instance (16 master nodes, 1 read replica) redis.logic.splitrw.sharding4g.16db.1rodb.32proxy.default 16 1 2,048 50,000 320,000 3,200,000
128 GB read/write splitting instance (16 master nodes, 1 read replica) redis.logic.splitrw.sharding8g.16db.1rodb.32proxy.default 16 1 2,048 50,000 320,000 3,200,000
256 GB read/write splitting instance (32 master nodes, 1 read replica) redis.logic.splitrw.sharding8g.32db.1rodb.64proxy.default 32 1 2,048 50,000 500,000 6,400,000
512 GB read/write splitting instance (32 master nodes, 1 read replica) redis.logic.splitrw.sharding16g.32db.1rodb.64proxy.default 32 1 2,048 50,000 500,000 6,400,000

Calculation rules for bandwidths

  • If network resources are sufficient, the bandwidth is unlimited. However, if network resources are insufficient, the maximum internal bandwidth is limited.
  • The bandwidth value in the table is the bandwidth of the instance. It is the sum of the bandwidth of all shards or nodes on the instance.
  • The upper limit of the total bandwidth for a read/write splitting instance (as shown in the table) is 2,048 MB/s. After the upper limit is reached, the bandwidth cannot be increased even if the number of shards or nodes is increased.
  • The bandwidth separately applies to the upstream bandwidth and downstream bandwidth. If the bandwidth of an instance is 10 MB/s, the upstream and downstream bandwidth of the instance are both 10 MB/s.
  • The bandwidth listed in the table is the internal bandwidth of the ApsaraDB for Redis instance. The Internet bandwidth depends on the internal bandwidth and is limited by the bandwidth of each connection between the instance and a client. We recommend that you connect to the instance over an internal network to maximize the performance.

Calculation rules for connections

  • The following example shows the maximum number of new connections that can be added per second: The maximum number of new connections per second of an instance is 10,000. The maximum number of connections 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 number of connections is 22,000 (12,000 + 10,000).
  • The maximum number of new connections per second and the maximum number of connections are the sum of the corresponding values of all shards or nodes on the instance. After 500,000 is reached, the maximum number of connections cannot be increased even if the number of shards or nodes is increased.

FAQ

Q: How can I create a read/write splitting cluster instance in the ApsaraDB for Redis console?

A: To create a read/write splitting cluster instance in the ApsaraDB for Redis console, perform the following steps:
  1. Log on to the ApsaraDB for Redis console. In the left-side navigation pane, click Instances, and click Create Instance. On the buy page that appears, set Architecture Type to Cluster.
  2. Set Shards to the number of shards on the read/write splitting instance.
  3. Select Master-Replica in the Node Type option.
  4. Select the specifications from the Instance Class drop-down list.