Batch Network Tuning Across ECS Fleet

Scenario

When deploying high-throughput or low-latency workloads across dozens of Alibaba Cloud Linux (Alinux) instances, manually SSH-ing into each node to apply TCP tuning, enable Shared Memory Communication (SMC), or configure XPS is error-prone and unscalable. This workflow leverages ECS Cloud Assistant to push standardized network optimization scripts to an entire fleet simultaneously, ensuring consistent kernel-level performance baselines without manual intervention.

Integration steps

1. Prepare the optimization script combining Alinux-specific tuning:

   #!/bin/bash
   modprobe smc
   sysctl -w net.ipv4.tcp_tw_reuse=1
   sysctl -w net.core.rmem_max=16777216
   echo 1 > /sys/class/net/eth0/queues/tx-0/xps_cpus

1. Create a Cloud Assistant command via CreateCommand. Set Type=RunShellScript, encode the script in Base64, and pass it to CommandContent.
2. Target your fleet by collecting InstanceIds or using TagKey/TagValue filters. Ensure all targets are Running and have the Cloud Assistant agent active.
3. Execute the batch job using RunCommand. Example CLI:

   aliyun ecs RunCommand \
     --RegionId cn-hangzhou \
     --CommandId c-xxxxxxxxxxxx \
     --InstanceIds '["i-uf614fhehhzmx", "i-uf614fhehhzmy"]' \
     --Timeout 300

1. Monitor execution via DescribeInvocationResults. Poll until InvokeStatus returns Success or Failed.
2. Validate remotely by issuing a follow-up RunCommand with sysctl net.ipv4.tcp_tw_reuse && lsmod | grep smc to confirm kernel changes.

Architecture

The workflow initiates from the ECS control plane via the RunCommand API. Requests route to the Cloud Assistant service, which pushes the Base64-encoded payload to the aliyun-service daemon on each target Alinux instance. The agent executes the script as root, applying sysctl and modprobe changes directly to the Linux kernel and network stack. Execution logs, stdout/stderr, and exit codes are asynchronously reported back to the ECS API, enabling centralized tracking without inbound SSH.

Prerequisites

• Target instances running Alibaba Cloud Linux 2/3 with Cloud Assistant agent installed and enabled.
• ECS RAM role with AliyunECSAssistantAccess attached to instances.
• Outbound HTTPS (443) to cloudassistant.aliyuncs.com (or regional VPC endpoint).
• Instances in Running state with valid VPC routing and security group egress rules.

Common pitfalls

• DNS/Endpoint Resolution: Instances without public DNS or internet access fail to reach the Cloud Assistant endpoint. Deploy a VPC endpoint (com.aliyun.ecs.cloudassistant) for private routing.
• Execution Timeouts: modprobe and sysctl reloads can stall. Always override the default 60s limit with --Timeout 300 in RunCommand.
• NetworkManager Overrides: Alinux’s NetworkManager may revert XPS or sysctl values on reboot. Persist settings via /etc/sysctl.d/99-network-tune.conf and disable conflicting NM profiles.
• Missing Kernel Modules: SMC requires CONFIG_SMC=y. On legacy Alinux 2 kernels, modprobe smc fails silently. Verify with uname -r and upgrade kernel if unsupported.

Typical questions

• batch apply network tuning to ECS instances
• remotely configure TCP parameters on Alinux fleet
• roll out SMC acceleration across instances
• Cloud Assistant push network optimization
• 批量远程优化ECS网络参数
• 通过云助手批量配置TCP内核参数
• 批量启用SMC加速

Q: How can I batch apply network tuning to an ECS fleet using Cloud Assistant? A: You can batch apply network tuning by creating a Base64-encoded shell script and executing it across your fleet using the ECS Cloud Assistant RunCommand API. Target your instances by InstanceIds or tags, ensure they are in a Running state with the agent active, and monitor progress via DescribeInvocationResults.

Q: How do I remotely configure TCP parameters across an Alibaba Cloud Linux fleet? A: Remotely configure TCP parameters by embedding sysctl commands into a Cloud Assistant script and deploying it to your Alinux instances. Override the default execution timeout to prevent stalls during kernel reloads, and validate the changes with a follow-up remote command.

Q: How can I roll out Shared Memory Communication (SMC) acceleration across multiple instances? A: Roll out SMC acceleration by adding the modprobe smc command to a Cloud Assistant optimization script and executing it across your target fleet. Verify that your instances run a compatible Alibaba Cloud Linux kernel with CONFIG_SMC=y enabled, and confirm module loading using a remote lsmod check.