This topic provides answers to some frequently asked questions about the bandwidth of ApsaraDB for Redis.
Is the bandwidth of an instance limited? What is the maximum bandwidth?
The bandwidth of Tair and Redis instances is limited. The maximum bandwidth varies based on the instance specifications.
You can use one of the following methods to query the maximum bandwidth of an instance:
Log on to the ApsaraDB for Redis console and go to the Instance Information page or call the DescribeIntranetAttribute operation.
Refer to the Overview topic.
Does bandwidth refer to internal bandwidth or external bandwidth?
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 example, if the maximum bandwidth of an instance of the tair.rdb.1g type is 96 Mbit/s, the total bandwidth available for a single shard is 96 Mbit/s, regardless of whether the connections to the shard are made over an internal network or the Internet.
Does bandwidth refer to upstream bandwidth or downstream bandwidth?
The bandwidth value applies to the upstream and downstream bandwidths. For example, if the bandwidth of an instance is 24 Mbit/s, the upstream and downstream bandwidths of the instance are both 24 Mbit/s.
How is the bandwidth of a cluster or read/write splitting instance calculated?
The total bandwidth of a cluster or read/write splitting instance is the sum of the bandwidths of all shards or replicas.
For example, if an instance has four shards of the redis.shard.with.proxy.small.ce type, and the bandwidth of each shard is 24 Mbit/s, the total bandwidth of the instance is 96 Mbit/s.
How do I upgrade the bandwidth of an instance?
You can increase the total bandwidth of a cluster or read/write splitting instance by increasing the number of shards or read replicas. For more information, see Adjust the number of shards for an instance and Enable read/write splitting.
NoteThe upper bandwidth limit for cluster instances in proxy mode is 2,048 Mbit/s. If the limit is reached, the bandwidth of an instance cannot be increased by adding shards. Cluster instances in direct connection mode have no limits on the overall bandwidth.
You can adjust the bandwidth of all types of instances except Tair ESSD-based instances. For more information, see Manually increase the bandwidth of an instance.
You can enable bandwidth auto scaling for ApsaraDB for Redis Community Edition instances, Tair DRAM-based instances, and instances that are deployed in local disk-based mode. For more information, see Enable bandwidth auto scaling.
Am I charged bandwidth and data transfer fees for using a Redis instance?
Data transfer fees: You are not charged data transfer fees for using a Redis instance.
Bandwidth fees: If you did not manually adjust the bandwidth of the instance or enable bandwidth auto scaling for the instance, you are not charged bandwidth fees. If you adjusted the bandwidth, you are charged bandwidth fees. For more information, see Billable items.
Why is the actual bandwidth of my instance different from the documented bandwidth?
Cause:
If your instance is a Redis Community Edition cloud disk-based instance that was created before June 20, 2023, the bandwidth of your instance may not match the documented bandwidth because Redis made adjustments to the default bandwidth of the instances on June 20, 2023. The bandwidth described in the specification document is the new bandwidth after the adjustment. As a result, the bandwidth of your instance is different from the documented bandwidth.
Solution:
The adjustment applies only to Redis Community Edition cloud disk-based instances that are created or modified after June 20, 2023.
To apply the increased default bandwidth to your existing instances, change the configurations of the instances on or after June 20, 2023. For example, you can upgrade the specifications or change the architecture for the instances.
For more information, see Default bandwidth is increased for Community Edition cloud-native instances (or cloud disk-based instances).
Which operation requires a key to occupy a large amount of bandwidth?
No built-in feature is available to directly query which operation requires a key to occupy a large amount of bandwidth.
For information about how to troubleshoot high traffic usage, see Troubleshoot high traffic usage on an ApsaraDB for Redis instance.