This topic provides answers to some frequently asked questions about the bandwidth of Tair (Redis OSS-compatible).
Is the bandwidth of an instance limited? What is the maximum bandwidth?
Tair and Redis Open-Source Edition instances have limits on the bandwidth of instances. The maximum bandwidth varies based on the instance type.
You can use one of the following methods to query the maximum bandwidth of an instance:
Log on to the Tair 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 limit of a Tair instance refers to the maximum bandwidth of each shard in the instance and is irrelevant to the network connection type.
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 maximum bandwidth of a cluster instance in proxy mode or a read/write splitting instance is 2,048 Mbit/s. After the upper limit is reached, the bandwidth cannot be increased even if you add more shards or nodes to the instance. 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 Redis Open-Source Edition instances and Tair DRAM-based instances that are deployed in classic mode. For more information, see Enable bandwidth auto scaling.
Am I charged bandwidth and data transfer fees for using a Tair instance?
Data transfer fees: You are not charged data transfer fees for using a Tair 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 about billing, see Billable items.
Why is the actual bandwidth of my instance different from the documented bandwidth?
Cause:
If your instance is a Redis Open-Source Edition cloud-native instance that was created before June 20, 2023, the bandwidth of your instance may not match the documented bandwidth because Alibaba Cloud adjusted the default bandwidth of Redis Open-Source Edition cloud-native 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 Open-Source Edition cloud-native 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 [Notice] Default bandwidth is increased for ApsaraDB for Redis Community Edition cloud-native 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.