Load balancing with eRPC

eRPC is a fault-tolerant EVM RPC proxy with persistent caching, optimized for read-intensive workloads such as data indexing and high-traffic frontends. For more details, refer to the eRPC Documentation.

note

For this tutorial, we will use the local inventory from the Ansible Avalanche Getting Started repository. Also ensure you have already created a Subnet and a blockchain; see Subnet Creation for details.

tip

Always make sure you have the latest version of the collection installed. See Installation and Upgrade.

Requirements

The ash.avalanche.erpc role relies on Docker, and the playbooks ash.avalanche.install_erpc_docker and ash.avalanche.install_erpc_network install Docker via the geerlingguy.docker role.

Install the required role locally with:

ansible-galaxy install -r ansible_collections/ash/avalanche/requirements.yml

Deployment Guide

There are two playbooks to deploy an eRPC instance using this Ansible role:

• Auto-detect Network and Nodes:
  This method automatically scans your Avalanche network, detects all available blockchains, and configures the corresponding endpoints on all accessible nodes in your avalanche_nodes group (as defined in your host inventory).

  Command

  ansible-playbook ash.avalanche.install_erpc_network -i inventories/local

• Custom Configuration:
  You can manually specify the node endpoints used by eRPC by setting the erpc_endpoint_list variable and define which blockchains to expose using erpc_chains. By default, the standard collection node URLs are used, and only the C-Chain is exposed.

  Command

  ansible-playbook ash.avalanche.install_erpc_docker -i inventories/local

info

In both cases, you can further customize additional variables such as erpc_include_c_chain, erpc_aliasing_rules, and erpc_limiters_budgets.

Endpoint Access

To access a chain, use its EVM chain ID:
<erpc-ip>:4000/<evm_chain_id>

Usage Example

After deploying eRPC, you can interact with the endpoints using:

Command

FRONTEND_IP=$(terraform -chdir=terraform/multipass output -raw frontend_ip)
curl -X POST --data '{"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]}' -H 'content-type:application/json;' $FRONTEND_IP:4000/43113

Output

{"jsonrpc":"2.0","id":1,"result":"0xa868"}

info

For advanced eRPC configurations, you can use the erpc_projects variable to set up dedicated projects. Additionally, erpc_aliasing_rules can be used to define aliases and erpc_limiters_budgets for setting up Rate Limiters.