Help Center/ Cloud Search Service/ Troubleshooting/ Clusters/ Unable to Connect to a Cluster from an ECS
Updated on 2025-10-11 GMT+08:00

Unable to Connect to a Cluster from an ECS

Perform the following steps to troubleshoot this problem:

  1. Check whether the ECS instance and cluster are in the same VPC.
    • If they are, go to 2.
    • If they are not, create an ECS instance and ensure that the ECS instance is in the same VPC as the cluster.
  2. View the security group rule setting of the cluster to check whether port 9200 (TCP protocol) is allowed or port 9200 is included in the port range allowed in both the outbound and inbound directions.
    • If it is allowed, go to 3.
    • If it is not allowed, switch to the VPC management console and configure the security group rule of the cluster to allow port 9200 in both the outbound and inbound directions.
  3. Check whether the ECS instance has been added to a security group.
    • If a security group has been created, check whether its rules are appropriate. If they are, go to 4.
    • If the instance has not been added to the security group, go to the VPC page from the ECS instance details page, select a security group, and add the ECS to the group.
  4. Check whether the ECS instance can connect to the CSS cluster.
    ssh <Private network address and port number of a node>

    If the cluster contains multiple nodes, test connectivity to each node.

    • If the connection is normal, the network is running properly.
    • If the connection still fails, contact technical support.