Help Center/ Distributed Cache Service/ User Guide/ Changing an Instance/ Adjusting the Bandwidth of a DCS Instance
Updated on 2026-08-27 GMT+08:00
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Adjusting the Bandwidth of a DCS Instance

As a data layer positioned close to application services, DCS Redis instances typically handle heavy read/write operations and consume significant network bandwidth. When the instance bandwidth is insufficient, bandwidth throttling may be triggered, leading to increased service latency and client connection errors. Currently, you can adjust the bandwidth on the console for DCS Redis 4.0 instances and later to fit your needs.

Notes and Constraints

  • Currently, the bandwidth of DCS Redis Enterprise Edition instances cannot be adjusted.
  • The bandwidth can be adjusted only for running instances.
  • The bandwidth of each shard can be adjusted from its default baseline bandwidth up to its maximum bandwidth. The maximum bandwidth per shard can reach 2,048 Mbit/s when the physical machine of the instance node has sufficient resources.
  • The target bandwidth must be an integer multiple of 8. Otherwise, the value will be automatically rounded down to a multiple of 8 after the order is submitted.
  • After the bandwidth of an instance is adjusted, if you change the instance specifications, the bandwidth will comply with the following rules:
    • When the instance is scaled up (the shard count remains unchanged but the shard capacity is changed), the new bandwidth per shard is calculated as the baseline bandwidth of the new specification plus the adjusted bandwidth of the shard.
    • When the shard count of an instance is changed, the bandwidth of existing shards is calculated as their baseline bandwidth plus the adjusted bandwidth. The bandwidth of the new shards defaults to the baseline bandwidth.
    • When you change the instance type between master/standby and Proxy Cluster, the instance bandwidth resets to the baseline bandwidth of the new instance, and the previously adjusted bandwidth of the original instance is automatically unsubscribed.

Billing

  • Bandwidth adjustments will result in fee changes. Note the estimated price displayed at the bottom of the bandwidth adjustment page. It covers only the incremental charges for the additional bandwidth on top of the baseline bandwidth and excludes the original instance configuration fees.
  • Bandwidth adjustments are supported only in pay-per-use billing mode (billed hourly).
  • You can adjust the bandwidth multiple times as needed. If multiple changes occur within a single billing period (one hour), you will be billed based on the maximum configured bandwidth during that period. For example, if you change the bandwidth of a DCS Redis instance from 256 Mbit/s (default) to 2,048 Mbit/s and then to 512 Mbit/s within a single billing period, you will be billed based on 2,048 Mbit/s for that period.

Video Tutorial

This video demonstrates how to adjust the bandwidth of a DCS instance. As product functions evolve, the GUI may vary. This tutorial is for reference only.

Procedure

By default, the bandwidth is manually adjusted, allowing you to specify the target bandwidth as needed. If you enable the Auto scaling function, you can choose to adjust the bandwidth either manually or automatically. If the function is unavailable on the console, submit a service ticket and contact the customer service.

  1. Log in to the DCS console.
  2. Click in the upper left corner of the console and select the region where your instance is located.
  3. In the navigation pane, choose Cache Manager.
  4. Click the name of a DCS instance.
  5. In the Instance Details area, click Adjust Bandwidth next to Bandwidth.

    Figure 1 Adjusting the bandwidth

  6. On the Adjust Bandwidth page, set Mode to Manual and modify bandwidth parameters.

    Figure 2 Manually setting the new bandwidth
    • To adjust the bandwidth for multiple shards on a Cluster instance, you can either specify a target bandwidth for each shard or select multiple shards and click Adjust Bandwidth in the upper left corner.
    • The target bandwidth must be an integer multiple of 8. Otherwise, the bandwidth will be automatically rounded down after the order is submitted. For example, if you enter 801, the target bandwidth will be adjusted to 800 Mbit/s.
    • Bandwidth adjustments will result in fee changes. For details, see Billing.

  7. Confirm the target bandwidth and fee, check Authorization, and click Submit.

    The new bandwidth takes effect immediately upon a successful adjustment. To view the new bandwidth, see Viewing the Assured and Current Bandwidths.

  1. Log in to the DCS console.
  2. Click in the upper left corner of the console and select the region where your instance is located.
  3. In the navigation pane, choose Cache Manager.
  4. Click the name of a DCS instance.
  5. In the Instance Details area, click Adjust Bandwidth next to Bandwidth.

    Figure 3 Adjusting the bandwidth

  6. On the Adjust Bandwidth page, set Mode to Auto scaling.
  7. Enable Auto Bandwidth Increase and set scaling policies as required, as shown in Table 1.

    Then the bandwidth increases automatically (up to 2,048 Mbit/s per shard) based on your configured scaling policies. Auto scaling overrides any previous manual adjustments.

    Figure 4 Configuring auto bandwidth scaling policies
    Table 1 Auto bandwidth scaling policies

    Policy

    Description

    Burst Bandwidth Usage ≥

    Average burst bandwidth usage threshold for triggering auto bandwidth scaling, as a percentage.

    Formula:

    Average burst bandwidth usage = Burst bandwidth/Shard bandwidth. In this formula, the burst bandwidth is calculated as the sum of the higher values between Output Flow and Input Flow within a monitoring period, divided by that period.

    Target:

    When the average burst bandwidth usage of a shard reaches the specified threshold, the shard bandwidth is automatically scaled up. After the scale-up, the average burst bandwidth usage is reduced to 90% of the threshold.

    For example, if the threshold is set to 70%, the shard bandwidth is automatically scaled up when the average burst bandwidth usage reaches 70%. After the scale-up, this usage is reduced to 60%. Therefore, the scaled-up shard bandwidth is calculated as the burst bandwidth divided by 60%.

    Monitoring Period

    Monitoring period for auto bandwidth scaling, in minutes. The default value is 1.

    For example, if the monitoring period is set to 1 minute, the bandwidth monitoring data is the average burst traffic within 1 minute.

    Silence

    Cooldown period for scaling operations, in seconds. The default value is 0.

    If the average burst bandwidth usage exceeds the threshold again after an automatic scale-up, the instance will not be scaled up within the specified cooldown period. This period prevents consecutive auto bandwidth scaling operations.

  8. Confirm the bandwidth parameters, check Authorization, and click Submit.

    When the message Automatic bandwidth scaling configured is displayed in the upper part of the page, the auto bandwidth scaling policies are configured. When the configured scaling policies are met, the instance bandwidth is automatically adjusted. You can choose Background Tasks in the navigation pane to view the auto bandwidth adjustment tasks performed for user system, as shown in Figure 5.

    Figure 5 Auto bandwidth adjustment records

Viewing the Assured and Current Bandwidths

On the Adjust Bandwidth page, you can view Assured and Current bandwidths of each shard. The Current column displays the bandwidths after adjustments.

Figure 6 Viewing the bandwidth
The relationship between the instance bandwidth and the bandwidth per shard is as follows:
  • Bandwidth of a single-node or master/standby instance = Bandwidth per shard
  • Bandwidth of a read/write splitting instance = Bandwidth per shard × Number of replicas
  • Bandwidth of a Cluster instance = Bandwidth per shard × Number of shards (If the shards have varying bandwidths, the instance bandwidth is the total bandwidth of all shards.)

    For example, a Cluster instance has three shards in Figure 6. If the adjusted bandwidth of each shard is 800 Mbit/s, the total bandwidth of the instance is 2,400 Mbit/s.

Helpful Links

Parent Topic: Changing an Instance