Vortex Proxy Engine

Vortex is a high-performance, programmable L7 proxy built entirely in Rust. Designed around a Hexagonal Architecture (Ports and Adapters) through a pure multi-crate Cargo workspace, it heavily emphasizes zero-overhead abstractions, non-blocking telemetry, and extreme tailorability via WebAssembly.

🚀 Why Vortex? (Our USP)

Vortex is the only API Gateway that natively merges eBPF kernel-level hardware packet drops with WebAssembly (Wasm) edge extensibility and lock-free Peak EWMA routing into a single, memory-safe Rust binary.

Unlike Envoy or NGINX which rely on heavy legacy C++ codebases or multiple sidecars to achieve these features, Vortex gives you 10M+ RPS capacity, instant L3/L4 DDoS mitigation, and dynamic Cloudflare-like edge compute natively in a sub-10MB distroless container.

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Workspace Architecture

Vortex is structured as a Cargo workspace using Hexagonal Architecture principles to decouple core domain logic from I/O boundaries:

• vortex-core: Pure domain models, generic traits (e.g., RateStore), circuit breaker states, and the Peak EWMA load-balancing algorithm. Completely decoupled from database and socket I/O.
• vortex-filters: WASM runtime engine (Wasmtime-backed), Proxy-WASM ABI host bindings, and the Redis-backed GCRA rate-limiter.
• vortex-admin: Local gRPC control plane over UNIX Domain Sockets (/tmp/vortex_admin.sock) and a Kubernetes Custom Resource Definition (CRD) watcher for zero-downtime routing swaps.
• vortex-ebpf: Pre-compiled kernel-space XDP filters (xdp_drop.c) and an Aya-based BPF loader.
• vortex-proxy: Top-level integration layer booting the Tokio runtime, pinning worker threads to CPU affinity, and managing TLS, QUIC, telemetry, and background sweepers.

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Key Features

1. Zero-Copy HTTP Pipeline & Lock-Free Hot Pool

Vortex uses hyper to process raw TCP byte-streams without allocating intermediate strings when acting as an L7 bridge. It incorporates a Hot Pool connection reuse mechanism, significantly amortizing the cost of TLS and TCP handshakes when talking to upstream microservices. Connections are pooled and managed lock-free.

2. Peak EWMA Load Balancing

We built a highly sensitive, lock-free Exponentially Weighted Moving Average (Peak EWMA) algorithm using atomic floating-point bit manipulation (AtomicU64).

• Instantly spikes the EWMA upon latency degradation points to shed load immediately.
• Implements an ActiveRequestGuard using RAII to mathematically penalize nodes with deep queue depths simultaneously.
• Executes sub-nanosecond scale routing score calculations (measured at ~394 picoseconds via criterion benchmarking).

3. Distributed GCRA Rate Limiting (Redis & Lua)

Vortex integrates a Redis-backed Generalized Cell Rate Algorithm (GCRA) implementation for distributed rate limiting.

• Utilizes purely atomic operations constructed via redis::Script (Lua) ensuring no race conditions for distributed edge clusters.
• Arc<deadpool_redis::Pool> connection abstraction isolates contention overheads from the request datapath.

4. Wasmtime Integration for Dynamic Edge Computing

To enable on-the-fly request modification, authentication offloading, and dynamic headers (e.g., Cloudflare Workers), we integrated the Bytecode Alliance wasmtime engine.

• Bytecodes can be hot-swapped over an internal Administrative UNIX Domain Socket via the vortex_admin gRPC service utilizing arc-swap.
• Achieves native execution speeds with robust sandboxing.

5. High-Resolution Telemetry & MPSC Exporter

Trace aggregation limits datapath speeds if implemented naively.

• W3C TraceContext headers are extracted and propagated directly at the edge.
• Span processing leverages an asynchronous, bounded mpsc::channel paired with the opentelemetry-otlp protocol to stream high-resolution vectors without throttling latency.
• Features Prometheus histograms natively accessible on a decoupled loopback listener (port 9091).

6. eBPF / XDP Kernel-Level Traffic Mitigation

To protect the backend from volumetric DDoS attacks, Vortex integrates an eBPF/XDP packet filter.

• Drops abusive packets directly at the network interface card (NIC) layer before they even reach the Linux network stack or the Rust application layer.
• Instantly mitigates L3/L4 attacks at line-rate.

7. Lock-Free Circuit Breakers

• Incorporates robust CircuitBreaker states (Closed, Open, HalfOpen) into the core domain.
• Automatically isolates failing backends from the routing table and returns structured 503 JSON errors, preventing cascading timeouts across the system.

8. Operational Robustness & Performance Hardening

• Wasmtime Pooling: Integrates the PoolingAllocationConfig to pre-warm up to 1,000 Wasm sandboxes, eliminating JIT memory fragmentation.
• Memory Allocation: Replaced system malloc with jemalloc (jemallocator) universally to eliminate memory fragmentation under 100k+ RPS concurrent loads.
• CPU Pinning: Integrated core_affinity to strictly pin Tokio worker threads to specific physical CPU pipelines, mitigating L1/L2 cache-miss latency penalties during context switches.
• HTTP/3 (QUIC) Ready: Initialized a pure quinn UDP listener side-by-side with TLS offloading, paving the way for advanced multiplexed QUIC streams at the edge.
• Graceful Shutdown: Employs tokio::sync::broadcast for zero-downtime listener draining on SIGINT.
• Kubernetes Native: Fully equipped with multi-stage Docker builds, HorizontalPodAutoscaler, and Argo Rollouts Canary progressive delivery manifests.

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Request Flow

sequenceDiagram
    participant C as Client
    participant V as Vortex Proxy
    participant F as Wasmtime Filters
    participant R as Redis (GCRA)
    participant B as Backend Service

    C->>V: HTTP/2 or QUIC Request
    V->>F: Execute Wasm bytecode (Headers)
    alt Wasm Rejects
        F-->>V: Deny / Modify
        V-->>C: 403 Forbidden
    else Wasm Allows
        F-->>V: Proceed
    end
    V->>R: Execute Lua Script (Limit Check)
    alt Limit Exceeded
        R-->>V: 429 Too Many Requests
        V-->>C: 429 Too Many Requests
    else Limit OK
        R-->>V: Allowed
    end
    V->>V: Peak EWMA Routing & Node Select
    V->>B: Forward Request (Lock-Free Pool)
    B-->>V: HTTP Response
    V->>V: Asynchronous OTLP Telemetry Export
    V-->>C: HTTP Response

Loading

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Technical Deep Dive & API References

1. The Peak EWMA Autonomous Load Balancer

Most proxies rely on Round-Robin or Least Connections. Under severe load spikes, these algorithms fail to react rapidly to degrading nodes (the "noisy neighbor" problem). Vortex implements an atomic, lock-free Peak EWMA (Exponentially Weighted Moving Average).

The Math & Logic:

• Recovery Decay: When latency is recovering (dropping), the EWMA updates using classical temporal decay: EWMA_new = (R * (1 - α)) + (EWMA_old * α) (where α is the decay rate, e.g., 0.5).
• Instant Peak Tracking: If latency spikes above the historical average, EWMA_new jumps instantly to R to immediately penalize the node.
• Routing Score: The final route score incorporates active queue depth via Score = (EWMA + 1) * (ActiveRequests + 1). A lower score wins. This calculation executes in ~394 picoseconds, allowing routing decisions to be made at hyper-scale without locking.

2. Wasmtime Execution Edge API

Vortex enables dynamic L7 filtering (headers manipulation, authentication, custom routing) via WebAssembly.

A. Direct Guest Execution

Vortex executes a .wasm filter compiled from C, Rust, or AssemblyScript by invoking its exported execute function:

(module
    (func (export "execute") (result i32)
        i32.const 200
    )
)

B. Standard Proxy-WASM ABI

Vortex has been upgraded to natively implement the standard Proxy-WASM ABI host environment. This allows Vortex to run thousands of existing Envoy, Istio, and Proxy-Wasm plugins out-of-the-box.

Vortex registers the following core Proxy-WASM ABI host functions on the Wasmtime Linker under the env module:

• proxy_log(level: i32, message_data: i32, message_size: i32) -> i32
• proxy_get_header_map_value(map_type: i32, key_data: i32, key_size: i32, return_value_data: i32, return_value_size: i32) -> i32
• proxy_continue_stream(stream_type: i32) -> i32

Vortex invokes the guest lifecycle handler proxy_on_request_headers to process request payloads:

;; Host calls guest callback with (root_context_id, plugin_context_id, stream_id)
(call $proxy_on_request_headers (i32.const 1) (i32.const 2) (i32.const 3))

---

3. Unix Socket Admin API (gRPC/ProtoBuf)

Vortex exposes a local Control Plane over a Unix Domain Socket (/tmp/vortex_admin.sock) using tonic (gRPC). This enables zero-downtime hot-reloading of routing rules, performance stats extraction, and plugin deployments.

Service Definition (admin.proto):

syntax = "proto3";
package vortex.admin;

service AdminService {
    rpc ReloadConfig (ReloadConfigRequest) returns (ReloadConfigResponse);
    rpc GetStats (GetStatsRequest) returns (GetStatsResponse);
    rpc UpdateWasmPlugin (UpdateWasmRequest) returns (UpdateWasmResponse);
}

message ReloadConfigRequest {
    string config_path = 1;
}

message ReloadConfigResponse {
    bool success = 1;
    string message = 2;
}

message GetStatsRequest {}

message GetStatsResponse {
    uint32 active_connections = 1;
}

message UpdateWasmRequest {
    bytes wasm_binary = 1;
}

message UpdateWasmResponse {
    bool success = 1;
    string message = 2;
}

State swaps are executed globally using the arc-swap crate, ensuring that active TCP streams maintain Arc references to their origin routing graphs indefinitely until disconnected, achieving true zero-downtime draining.

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4. Kubernetes Custom Resource (VortexRoute) Watcher

Vortex incorporates a Kubernetes controller that watches the API Server namespaces for updates on Custom Resources representing routing topologies. The watcher utilizes kube-rs to subscribe to events and perform atomic routing table swaps.

Custom Resource Definition Spec (vortex.dev/v1alpha1, Kind: VortexRoute): A VortexRoute custom resource defines backends and optional metadata such as supported AI models.

Example Manifest:

apiVersion: vortex.dev/v1alpha1
kind: VortexRoute
metadata:
  name: main-routing-topology
  namespace: default
spec:
  backends:
    - id: 1
      address: "10.0.1.10:8443"
      ai_models:
        - "gpt-4"
        - "gpt-3.5-turbo"
    - id: 2
      address: "10.0.1.20:8443"
      ai_models:
        - "claude-3-opus"

---

5. eBPF/XDP Rate Limiting & BanManager Sweeper

When a downstream client exhausts its rate limits (based on GCRA Redis checks), Vortex triggers a kernel-space ban to defend the proxy at line-rate.

• Kernel Banishment: The BanManager uses vortex-ebpf to insert the abusive client's IPv4 address into the BLOCKED_IPS BPF map.
• XDP Early Drop: The eBPF/XDP filter program (xdp_drop.c) intercepts packets directly at the NIC layer (eth0) and returns XDP_DROP if the source IP matches the map, bypassing the kernel network stack and the Rust user-space binary entirely.
• Background Sweeper: A background thread runs a sweeper loop at a specified interval (e.g., every 5 seconds) to clean up expired IP bans. It calls unblock_ip to remove the IP from the BPF map, allowing the client to reconnect.

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6. Data Plane API Responses (Client-Facing)

VortexProxy interacts with downstream clients through standard HTTP semantics, intercepting abusive or failing traffic natively.

• 429 Too Many Requests: Triggered when the distributed GCRA Redis token bucket is exhausted for a specific client IP.

  {
    "error": "Rate limit exceeded",
    "retry_after_ms": 1500
  }

• 503 Service Unavailable: Triggered when the Peak EWMA router detects that all upstream nodes are unreachable, or when the atomic Circuit Breaker flips to the Open state.

  {
    "error": "Service Unavailable",
    "message": "Circuit breaker open or all backend nodes are offline."
  }

• 403 Forbidden: Triggered when the dynamic Wasmtime filter explicitly rejects a request (e.g., invalid Authentication headers or unauthorized JWT tokens) returning a proxy_pause ABI code.

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Getting Started

Prerequisites

• Rust (latest stable)
• Redis (running locally on port 6379 for distributed rate limiting)
• Protobuf Compiler (protoc) for compiling gRPC schemas

Building and Running

1. Clone the repository:

   git clone <repository-url>
   cd vortex-proxy

2. Generate self-signed certificates (for development TLS & QUIC): Vortex expects certs/cert.pem and certs/key.pem in the root directory for TLS and QUIC listeners.

   mkdir -p certs
   openssl req -x509 -newkey rsa:4096 -keyout certs/key.pem -out certs/cert.pem -days 365 -nodes -subj "/CN=localhost"

3. Compile and run the proxy:

   make build
   cargo run --release -p vortex-proxy

4. Run tests and benchmarks:

   make test
   make bench

5. Run lint checks and formatter:

   make lint
   make format

6. Deploy to Kubernetes:

   make docker-build
   make k8s-deploy

7. Perform load testing: Vortex comes with a load-testing script utilizing Vegeta:

   make load-test

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🤝 Contributing

We are actively looking for open-source contributors to help push Vortex to the absolute limits of edge computing!

How you can help:

• eBPF & XDP: Expand our kernel-level networking filters to drop specific DDoS attack vectors natively.
• Wasm Plugins: Build and share custom Proxy-WASM plugins (e.g., JWT validators, Rate Limiters) written in Rust, Go, or AssemblyScript.
• Protocol Support: Help us finalize full HTTP/3 (QUIC) and gRPC multiplexing support.
• Observability: Integrate deeper OpenTelemetry tracing metrics and Jaeger dashboards.

Check out our issues tab, fork the repository, and submit a Pull Request! All code must pass make lint and make test.

Join us in building the fastest, safest, and most programmable L7 proxy in the open-source ecosystem!