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 queries per second (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 shards, 1 read replica) indicates that the instance has two shards. Each shard contains one read replica.
Specification 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 shards, 1 read replica) redis.logic.splitrw.sharding2g.2db.1rodb.4proxy.default 2 1 384 50000 40000 400000
8 GB read/write splitting instance (2 shards, 1 read replica) redis.logic.splitrw.sharding4g.2db.1rodb.4proxy.default 2 1 384 50000 40000 400000
16 GB read/write splitting instance (2 shards, 1 read replica) redis.logic.splitrw.sharding8g.2db.1rodb.8proxy.default 2 1 384 50000 40000 400000
32 GB read/write splitting instance (8 shards, 1 read replica) redis.logic.splitrw.sharding4g.8db.1rodb.16proxy.default 8 1 1536 50000 160000 1600000
64 GB read/write splitting instance (16 shards, 1 read replica) redis.logic.splitrw.sharding4g.16db.1rodb.32proxy.default 16 1 2048 50000 320000 3200000
128 GB read/write splitting instance (16 shards, 1 read replica) redis.logic.splitrw.sharding8g.16db.1rodb.32proxy.default 16 1 2048 50000 320000 3200000
256 GB read/write splitting instance (32 shards, 1 read replica) redis.logic.splitrw.sharding8g.32db.1rodb.64proxy.default 32 1 2048 50000 500000 6400000
512 GB read/write splitting instance (32 shards, 1 read replica) redis.logic.splitrw.sharding16g.32db.1rodb.64proxy.default 32 1 2048 50000 500000 6400000

Calculation rules for bandwidth

  • If network resources are sufficient, the bandwidth is unlimited. However, if network resources are insufficient, the maximum instance 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 Mbit/s. After the upper limit is reached, the bandwidth cannot be increased even if the number of shards or nodes is increased.
  • The bandwidth value applies to the upstream and downstream bandwidths. 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 listed in the table is the internal bandwidth of the ApsaraDB for Redis instance. The Internet bandwidth is determined by the internal bandwidth and is limited by the bandwidth of the 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 created 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 in the preceding table both refer to the total number of connections of the instance in proxy mode. The maximum number of connections is 500,000 or less. After the value is reached, the maximum number of connections is not increased even if the number of shards or nodes is increased.
    Note If you enable direct connection for a cluster instance, the connectivity performance of the instance degrades because the proxy node is bypassed. For cluster instances of Community Edition, the maximum number of connections for a single shard is 10,000, and the maximum number of new connections per second is 2,000. For cluster instances of Enhanced Edition, the maximum number of connections for an individual shard is 30,000, the maximum number of new connections per second is 2,000.

FAQ

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

A: To create a read/write splitting cluster instance in the 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. Set Node Type to Master-Replica.
  4. Select the specifications from the Instance Class drop-down list.