CSS integrates shared load balancers, through which you can enable access to a cluster from the public network as well as through the VPC Endpoint service. Dedicated load balancers provide higher performance and more diverse features than shared load balancers. This topic describes how to configure a dedicated load balancer for a cluster.
Advantages of connecting to a cluster through a dedicated load balancer:
There are eight different ELB service forms for clusters in different security modes to connect to a dedicated load balancer. Table 1 describes the ELB capabilities for different cluster configurations. Table 2 describes the configurations for different ELB service forms.
Security Mode | Service Form Provided by ELB for External Systems | ELB Load Balancing | ELB Traffic Monitoring | ELB Two-way Authentication |
|---|---|---|---|---|
Non-security mode | No authentication | Supported | Supported | Not supported |
One-way authentication Two-way authentication | Supported | Supported | Supported | |
Security mode + HTTP | Password authentication | Supported | Supported | Not supported |
One-way authentication + Password authentication Two-way authentication + Password authentication | Supported | Supported | Supported | |
Security mode + HTTPS | One-way authentication + Password authentication Two-way authentication + Password authentication | Supported | Supported | Supported |
Security Mode | Service Form Provided by ELB for External Systems | ELB Listener | ELB Listener | ELB Listener | Backend Server Group | Backend Server Group | Backend Server Group |
|---|---|---|---|---|---|---|---|
Frontend Protocol | Frontend Port | SSL Authentication | Backend Protocol | Health Check Port | Health Check Path | ||
Non-security mode | No authentication | HTTP | 9200 | No authentication | HTTP | 9200 | / |
One-way authentication | HTTPS | 9200 | One-way authentication | HTTP | 9200 | ||
Two-way authentication | HTTPS | 9200 | Two-way authentication | HTTP | 9200 | ||
Security mode + HTTP | Password authentication | HTTP | 9200 | No authentication | HTTP | 9200 | /_opendistro/_security/health |
One-way authentication + Password authentication | HTTPS | 9200 | One-way authentication | HTTP | 9200 | ||
Two-way authentication + Password authentication | HTTPS | 9200 | Two-way authentication | HTTP | 9200 | ||
Security mode + HTTPS | One-way authentication + Password authentication | HTTPS | 9200 | One-way authentication | HTTPS | 9200 | |
Two-way authentication + Password authentication | HTTPS | 9200 | Two-way authentication | HTTPS | 9200 |
Parameter | Description |
|---|---|
Load Balancer | Select the dedicated load balancer you have created earlier. To create a dedicated load balancer, see . |
Agency | To configure a load balancer, you must have the permission to access ELB resources. By configuring an IAM agency, you can authorize CSS to access its ELB resources through an associated account.
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Load balancer information is displayed.
to configure listener information.
Parameter | Description |
|---|---|
Frontend Protocol | Protocol used by the client and listener to distribute traffic. Select HTTP or HTTPS. Select this protocol based on your connectivity needs. |
Frontend Port | Port used by the client and listener to distribute traffic. Set this parameter based on site requirements. |
SSL Authentication | Client authentication mode. Set this parameter only when Frontend Protocol is set to HTTPS. Both one-way and two-way authentication are supported. Select an authentication mode that suits your needs. |
Server Certificate | The server certificate is used for SSL handshake. The certificate content and private key must be provided. It is required only when Frontend Protocol is set to HTTPS. Select the server certificate created on ELB. |
CA Certificate | Also called client CA public key certificate. It is used to verify the issuer of a client certificate. It is required only when SSL Authentication is set to Two-way authentication. Select the CA certificate created on ELB. When HTTPS two-way authentication is enabled, an HTTPS connection can be established only when the client can provide the certificate issued by a trusted CA. |
Figure 1 Configuring a listener

Without access control policies, all IP addresses are allowed to access the CSS cluster through this load balancer, which may create security risks.
Health Check Result | Description |
|---|---|
Normal | The node IP address is connected. |
Abnormal | The node IP address is disconnected. |
Choose Load Balancing > OpenSearch, toggle off Load Balancing. In the displayed dialog box, click OK.
After the load balancer is disassociated, any listener or backend server group configurations will be permanently deleted.
You are not advised to connect a load balancer that has been associated with a public IP address to a non-security mode cluster. Access from the public network using such a load balancer may cause security risks because a non-security mode cluster can be accessed using HTTP without security authentication.
Security Mode | Service Form Provided by ELB for External Systems | cURL Command for Accessing a Cluster |
|---|---|---|
Non-security mode | No authentication |
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One-way authentication |
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Two-way authentication |
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Security mode + HTTP | Password authentication |
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One-way authentication + Password authentication |
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Two-way authentication + Password authentication |
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Security mode + HTTPS | One-way authentication + Password authentication |
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Two-way authentication + Password authentication |
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Variable | Description |
|---|---|
IP | IP address of a load balancer instance. |
port | Frontend protocol and port configured for the listener. |
user | Username of the cluster. This parameter is required only for a security-mode cluster. |
pwd | Password of the username above. This parameter is required only for a security-mode cluster. |
If cluster information is returned, the connection is successful.