FAQ

Yes, but this requires additional configuration.

By default, client libraries (SDKs) send all heavy requests (read/write) to the proxy group with the role default. If you create a group with the heavy role in the operator but do not reconfigure the cluster, the SDK won't know about it and will continue routing requests to the default role, for which no proxies are configured.

To redirect standard client traffic to the new group, change the @default_role_filter attribute in Cypress:

# Now, clients that don't explicitly specify a role will be directed to proxies with the 'heavy' role.
yt set //sys/http_proxies/@default_role_filter heavy

Technically, yes, but it's not recommended for high-load installations. If you configure clients to work without Discovery (only through Ingress), three problems arise:

• Double load balancing. All traffic passes through an intermediate Ingress controller, increasing latency.
• Configuration complexity. To make Discovery work through Ingress, you'll need to create a separate Ingress resource and DNS name for each Data proxy pod.
• Transaction issues. You must configure sticky sessions.

For high-load installations, a combined approach is recommended:

• L7 (Ingress): Use only for Control traffic (role control). This provides a clear domain name, SSL, and convenience for users.
• L4 (NodePort/LoadBalancer): Use for Data traffic (role default). This allows clients to connect directly to pods (via Discovery and Advertised Addresses), ensuring maximum throughput without a bottleneck from the Ingress controller.

This indicates misconfigured (or unconfigured) Discovery.

Lightweight commands go through control proxies. Heavy commands (read-table, write-table) try to connect directly to Data proxies. A "Name resolution failure" or "Connection refused" error on write means that Discovery is returning the pods' internal addresses to the client.

Configure address substitution via the //sys/http_proxies/@balancers attribute (see the section Configure address substitution).

Yes, the Discovery mechanism can be disabled on the client side (config option enable_proxy_discovery=%false). This is convenient for quick debugging and testing: traffic stops being split and is directed to a single entry point.

Examples of how to disable Discovery:

client = yt.YtClient(proxy="localhost:8080", config={"proxy": {"enable_proxy_discovery": False}})

export YT_USE_HOSTS=0
# Or:
# export YT_CONFIG_PATCHES='{proxy={enable_proxy_discovery=%false}}'

Yes, the role of a specific instance can be changed on the fly by modifying the @role attribute in Cypress. This is useful for temporarily removing a proxy from the active pool without restarting it.

Example of changing a role via the CLI:

# Assign the 'control' role to a specific proxy
yt set //sys/http_proxies/hp-0.http-proxies.default.svc.cluster.local:80/@role control