handle batched requests

This commit is contained in:
Bryan Stitt 2022-05-11 23:50:52 +00:00
parent 969f88d4bb
commit 3914a41fa2
9 changed files with 678 additions and 429 deletions

4
Cargo.lock generated

@ -3333,9 +3333,9 @@ checksum = "cda74da7e1a664f795bb1f8a87ec406fb89a02522cf6e50620d016add6dbbf5c"
[[package]]
name = "tokio"
version = "1.18.1"
version = "1.18.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "dce653fb475565de9f6fb0614b28bca8df2c430c0cf84bcd9c843f15de5414cc"
checksum = "4903bf0427cf68dddd5aa6a93220756f8be0c34fcfa9f5e6191e103e15a31395"
dependencies = [
"bytes",
"libc",

@ -6,24 +6,3 @@
url = "ws://127.0.0.1:8546"
soft_limit = 200_000
[balanced_rpc_tiers.0.ankr]
url = "https://rpc.ankr.com/eth"
soft_limit = 3_000
[private_rpcs]
[private_rpcs.eden]
url = "https://api.edennetwork.io/v1/"
soft_limit = 1_805
[private_rpcs.eden_beta]
url = "https://api.edennetwork.io/v1/beta"
soft_limit = 5_861
[private_rpcs.ethermine]
url = "https://rpc.ethermine.org"
soft_limit = 5_861
[private_rpcs.flashbots]
url = "https://rpc.flashbots.net"
soft_limit = 7074

29
config/example.toml.bac Normal file

@ -0,0 +1,29 @@
[balanced_rpc_tiers]
[balanced_rpc_tiers.0]
[balanced_rpc_tiers.0.geth]
url = "ws://127.0.0.1:8546"
soft_limit = 200_000
[balanced_rpc_tiers.0.ankr]
url = "https://rpc.ankr.com/eth"
soft_limit = 3_000
[private_rpcs]
[private_rpcs.eden]
url = "https://api.edennetwork.io/v1/"
soft_limit = 1_805
[private_rpcs.eden_beta]
url = "https://api.edennetwork.io/v1/beta"
soft_limit = 5_861
[private_rpcs.ethermine]
url = "https://rpc.ethermine.org"
soft_limit = 5_861
[private_rpcs.flashbots]
url = "https://rpc.flashbots.net"
soft_limit = 7074

@ -22,7 +22,7 @@ reqwest = { version = "0.11.10", default-features = false, features = ["json", "
rustc-hash = "1.1.0"
serde = { version = "1.0.137", features = [] }
serde_json = { version = "1.0.81", default-features = false, features = ["alloc"] }
tokio = { version = "1.18.1", features = ["full"] }
tokio = { version = "1.18.2", features = ["full"] }
toml = "0.5.9"
tracing = "0.1.34"
tracing-subscriber = "0.3.11"

415
web3-proxy/src/app.rs Normal file

@ -0,0 +1,415 @@
use crate::config::Web3ConnectionConfig;
use crate::connections::Web3Connections;
use crate::jsonrpc::JsonRpcErrorData;
use crate::jsonrpc::JsonRpcForwardedResponse;
use crate::jsonrpc::JsonRpcForwardedResponseEnum;
use crate::jsonrpc::JsonRpcRequest;
use crate::jsonrpc::JsonRpcRequestEnum;
use ethers::prelude::ProviderError;
use ethers::prelude::{HttpClientError, WsClientError};
use futures::future;
use futures::future::join_all;
use governor::clock::{Clock, QuantaClock};
use linkedhashmap::LinkedHashMap;
use std::fmt;
use std::sync::atomic::{self, AtomicU64};
use std::sync::Arc;
use std::time::Duration;
use tokio::sync::RwLock;
use tokio::time::sleep;
use tracing::{trace, warn};
static APP_USER_AGENT: &str = concat!(
"satoshiandkin/",
env!("CARGO_PKG_NAME"),
"/",
env!("CARGO_PKG_VERSION"),
);
// TODO: put this in config? what size should we do?
const RESPONSE_CACHE_CAP: usize = 1024;
/// TODO: these types are probably very bad keys and values. i couldn't get caching of warp::reply::Json to work
type ResponseLruCache = RwLock<LinkedHashMap<(u64, String, String), JsonRpcForwardedResponse>>;
/// The application
// TODO: this debug impl is way too verbose. make something smaller
// TODO: if Web3ProxyApp is always in an Arc, i think we can avoid having at least some of these internal things in arcs
pub struct Web3ProxyApp {
best_head_block_number: Arc<AtomicU64>,
/// clock used for rate limiting
/// TODO: use tokio's clock (will require a different ratelimiting crate)
clock: QuantaClock,
/// Send requests to the best server available
balanced_rpc_tiers: Vec<Arc<Web3Connections>>,
/// Send private requests (like eth_sendRawTransaction) to all these servers
private_rpcs: Option<Arc<Web3Connections>>,
response_cache: ResponseLruCache,
}
impl fmt::Debug for Web3ProxyApp {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
// TODO: the default formatter takes forever to write. this is too quiet though
f.debug_struct("Web3ProxyApp")
.field(
"best_head_block_number",
&self.best_head_block_number.load(atomic::Ordering::Relaxed),
)
.finish_non_exhaustive()
}
}
impl Web3ProxyApp {
pub async fn try_new(
balanced_rpc_tiers: Vec<Vec<Web3ConnectionConfig>>,
private_rpcs: Vec<Web3ConnectionConfig>,
) -> anyhow::Result<Web3ProxyApp> {
let clock = QuantaClock::default();
let best_head_block_number = Arc::new(AtomicU64::new(0));
// make a http shared client
// TODO: how should we configure the connection pool?
// TODO: 5 minutes is probably long enough. unlimited is a bad idea if something is wrong with the remote server
let http_client = reqwest::ClientBuilder::new()
.connect_timeout(Duration::from_secs(5))
.timeout(Duration::from_secs(300))
.user_agent(APP_USER_AGENT)
.build()?;
// TODO: attach context to this error
let balanced_rpc_tiers =
future::join_all(balanced_rpc_tiers.into_iter().map(|balanced_rpc_tier| {
Web3Connections::try_new(
best_head_block_number.clone(),
balanced_rpc_tier,
Some(http_client.clone()),
&clock,
)
}))
.await
.into_iter()
.collect::<anyhow::Result<Vec<Arc<Web3Connections>>>>()?;
// TODO: attach context to this error
let private_rpcs = if private_rpcs.is_empty() {
warn!("No private relays configured. Any transactions will be broadcast to the public mempool!");
// TODO: instead of None, set it to a list of all the rpcs from balanced_rpc_tiers. that way we broadcast very loudly
None
} else {
Some(
Web3Connections::try_new(
best_head_block_number.clone(),
private_rpcs,
Some(http_client),
&clock,
)
.await?,
)
};
Ok(Web3ProxyApp {
best_head_block_number,
clock,
balanced_rpc_tiers,
private_rpcs,
response_cache: Default::default(),
})
}
/// send the request to the approriate RPCs
/// TODO: dry this up
pub async fn proxy_web3_rpc(
self: Arc<Web3ProxyApp>,
request: JsonRpcRequestEnum,
) -> anyhow::Result<impl warp::Reply> {
trace!("Received request: {:?}", request);
let response = match request {
JsonRpcRequestEnum::Single(request) => {
JsonRpcForwardedResponseEnum::Single(self.proxy_web3_rpc_request(request).await?)
}
JsonRpcRequestEnum::Batch(requests) => {
JsonRpcForwardedResponseEnum::Batch(self.proxy_web3_rpc_requests(requests).await?)
}
};
Ok(warp::reply::json(&response))
}
async fn proxy_web3_rpc_requests(
self: Arc<Web3ProxyApp>,
requests: Vec<JsonRpcRequest>,
) -> anyhow::Result<Vec<JsonRpcForwardedResponse>> {
// TODO: we should probably change ethers-rs to support this directly
// we cut up the request and send to potentually different servers. this could be a problem.
// if the client needs consistent blocks, they should specify instead of assume batches work on the same
// TODO: is spawning here actually slower?
let num_requests = requests.len();
let responses = join_all(
requests
.into_iter()
.map(|request| {
let clone = self.clone();
tokio::spawn(async move { clone.proxy_web3_rpc_request(request).await })
})
.collect::<Vec<_>>(),
)
.await;
// TODO: i'm sure this could be done better with iterators
let mut collected: Vec<JsonRpcForwardedResponse> = Vec::with_capacity(num_requests);
for response in responses {
collected.push(response??);
}
Ok(collected)
}
async fn proxy_web3_rpc_request(
self: Arc<Web3ProxyApp>,
request: JsonRpcRequest,
) -> anyhow::Result<JsonRpcForwardedResponse> {
trace!("Received request: {:?}", request);
// TODO: apparently json_body can be a vec of multiple requests. should we split them up? we need to respond with a Vec too
if self.private_rpcs.is_some() && request.method == "eth_sendRawTransaction" {
let private_rpcs = self.private_rpcs.as_ref().unwrap();
// there are private rpcs configured and the request is eth_sendSignedTransaction. send to all private rpcs
loop {
// TODO: think more about this lock. i think it won't actually help the herd. it probably makes it worse if we have a tight lag_limit
match private_rpcs.get_upstream_servers() {
Ok(active_request_handles) => {
let (tx, rx) = flume::unbounded();
let connections = private_rpcs.clone();
let method = request.method.clone();
let params = request.params.clone();
// TODO: benchmark this compared to waiting on unbounded futures
// TODO: do something with this handle?
tokio::spawn(async move {
connections
.try_send_parallel_requests(
active_request_handles,
method,
params,
tx,
)
.await
});
// wait for the first response
let backend_response = rx.recv_async().await?;
if let Ok(backend_response) = backend_response {
// TODO: i think we
let response = JsonRpcForwardedResponse {
jsonrpc: "2.0".to_string(),
id: request.id,
result: Some(backend_response),
error: None,
};
return Ok(response);
}
}
Err(not_until) => {
// TODO: move this to a helper function
// sleep (TODO: with a lock?) until our rate limits should be available
// TODO: if a server catches up sync while we are waiting, we could stop waiting
if let Some(not_until) = not_until {
let deadline = not_until.wait_time_from(self.clock.now());
sleep(deadline).await;
}
}
};
}
} else {
// this is not a private transaction (or no private relays are configured)
// try to send to each tier, stopping at the first success
// if no tiers are synced, fallback to privates
loop {
// there are multiple tiers. save the earliest not_until (if any). if we don't return, we will sleep until then and then try again
let mut earliest_not_until = None;
// TODO: how can we better build this iterator?
let rpc_iter = if let Some(private_rpcs) = self.private_rpcs.as_ref() {
self.balanced_rpc_tiers.iter().chain(vec![private_rpcs])
} else {
self.balanced_rpc_tiers.iter().chain(vec![])
};
for balanced_rpcs in rpc_iter {
let best_head_block_number =
self.best_head_block_number.load(atomic::Ordering::Acquire); // TODO: we don't store current block for everything anymore. we store it on the connections
let best_rpc_block_number = balanced_rpcs.head_block_number();
if best_rpc_block_number < best_head_block_number {
continue;
}
// TODO: building this cache key is slow and its large, but i don't see a better way right now
// TODO: inspect the params and see if a block is specified. if so, use that block number instead of current_block
let cache_key = (
best_head_block_number,
request.method.clone(),
request.params.to_string(),
);
if let Some(cached) = self.response_cache.read().await.get(&cache_key) {
// TODO: this still serializes every time
// TODO: return a reference in the other places so that this works without a clone?
return Ok(cached.to_owned());
}
// TODO: what allowed lag?
match balanced_rpcs.next_upstream_server().await {
Ok(active_request_handle) => {
let response = balanced_rpcs
.try_send_request(
active_request_handle,
&request.method,
&request.params,
)
.await;
let response = match response {
Ok(partial_response) => {
// TODO: trace here was really slow with millions of requests.
// info!("forwarding request from {}", upstream_server);
let response = JsonRpcForwardedResponse {
jsonrpc: "2.0".to_string(),
id: request.id,
// TODO: since we only use the result here, should that be all we return from try_send_request?
result: Some(partial_response),
error: None,
};
// TODO: small race condidition here. parallel requests with the same query will both be saved to the cache
let mut response_cache = self.response_cache.write().await;
// TODO: cache the warp::reply to save us serializing every time
response_cache.insert(cache_key, response.clone());
if response_cache.len() >= RESPONSE_CACHE_CAP {
response_cache.pop_front();
}
response
}
Err(e) => {
let code;
let message: String;
let data;
match e {
ProviderError::JsonRpcClientError(e) => {
// TODO: we should check what type the provider is rather than trying to downcast both types of errors
if let Some(e) = e.downcast_ref::<HttpClientError>() {
match &*e {
HttpClientError::JsonRpcError(e) => {
code = e.code;
message = e.message.clone();
data = e.data.clone();
}
e => {
// TODO: improve this
code = -32603;
message = format!("{}", e);
data = None;
}
}
} else if let Some(e) =
e.downcast_ref::<WsClientError>()
{
match &*e {
WsClientError::JsonRpcError(e) => {
code = e.code;
message = e.message.clone();
data = e.data.clone();
}
e => {
// TODO: improve this
code = -32603;
message = format!("{}", e);
data = None;
}
}
} else {
unimplemented!();
}
}
_ => {
code = -32603;
message = format!("{}", e);
data = None;
}
}
JsonRpcForwardedResponse {
jsonrpc: "2.0".to_string(),
id: request.id,
result: None,
error: Some(JsonRpcErrorData {
code,
message,
data,
}),
}
}
};
if response.error.is_some() {
trace!("Sending error reply: {:?}", response);
} else {
trace!("Sending reply: {:?}", response);
}
return Ok(response);
}
Err(None) => {
// TODO: this is too verbose. if there are other servers in other tiers, we use those!
// warn!("No servers in sync!");
}
Err(Some(not_until)) => {
// save the smallest not_until. if nothing succeeds, return an Err with not_until in it
// TODO: helper function for this
if earliest_not_until.is_none() {
earliest_not_until.replace(not_until);
} else {
let earliest_possible =
earliest_not_until.as_ref().unwrap().earliest_possible();
let new_earliest_possible = not_until.earliest_possible();
if earliest_possible > new_earliest_possible {
earliest_not_until = Some(not_until);
}
}
}
}
}
// we haven't returned an Ok
// if we did return a rate limit error, sleep and try again
if let Some(earliest_not_until) = earliest_not_until {
let deadline = earliest_not_until.wait_time_from(self.clock.now());
// TODO: max wait
sleep(deadline).await;
} else {
// TODO: how long should we wait?
// TODO: max wait time?
warn!("No servers in sync!");
// TODO: return json error? return a 502?
return Err(anyhow::anyhow!("no servers in sync"));
};
}
}
}
}

@ -1,4 +1,4 @@
///! Communicate with a web3 provider
///! Rate-limited communication with a web3 provider
use derive_more::From;
use ethers::prelude::Middleware;
use futures::StreamExt;
@ -7,7 +7,6 @@ use governor::middleware::NoOpMiddleware;
use governor::state::{InMemoryState, NotKeyed};
use governor::NotUntil;
use governor::RateLimiter;
use serde::{Deserialize, Serialize};
use serde_json::value::RawValue;
use std::fmt;
use std::num::NonZeroU32;
@ -274,7 +273,7 @@ impl Web3Connection {
}
}
/// Drop this once a connection to completes
/// Drop this once a connection completes
pub struct ActiveRequestHandle(Arc<Web3Connection>);
impl ActiveRequestHandle {
@ -351,50 +350,3 @@ impl PartialEq for Web3Connection {
== other.active_requests.load(atomic::Ordering::Acquire)
}
}
#[derive(Clone, Deserialize)]
pub struct JsonRpcRequest {
pub id: Box<RawValue>,
pub method: String,
pub params: Box<RawValue>,
}
impl fmt::Debug for JsonRpcRequest {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
// TODO: the default formatter takes forever to write. this is too quiet though
f.debug_struct("JsonRpcRequest")
.field("id", &self.id)
.finish_non_exhaustive()
}
}
#[derive(Serialize, Clone)]
pub struct JsonRpcErrorData {
/// The error code
pub code: i64,
/// The error message
pub message: String,
/// Additional data
#[serde(skip_serializing_if = "Option::is_none")]
pub data: Option<serde_json::Value>,
}
#[derive(Clone, Serialize)]
pub struct JsonRpcForwardedResponse {
pub jsonrpc: String,
pub id: Box<RawValue>,
#[serde(skip_serializing_if = "Option::is_none")]
pub result: Option<Box<RawValue>>,
#[serde(skip_serializing_if = "Option::is_none")]
pub error: Option<JsonRpcErrorData>,
// TODO: optional error
}
impl fmt::Debug for JsonRpcForwardedResponse {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
// TODO: the default formatter takes forever to write. this is too quiet though
f.debug_struct("JsonRpcForwardedResponse")
.field("id", &self.id)
.finish_non_exhaustive()
}
}

@ -1,4 +1,4 @@
///! Communicate with a group of web3 providers
///! Load balanced communication with a group of web3 providers
use derive_more::From;
use futures::stream::FuturesUnordered;
use futures::StreamExt;
@ -109,27 +109,28 @@ impl Web3Connections {
pub async fn try_send_request(
&self,
connection_handle: ActiveRequestHandle,
active_request_handle: ActiveRequestHandle,
method: &str,
params: &RawValue,
) -> Result<Box<RawValue>, ethers::prelude::ProviderError> {
let response = connection_handle.request(method, params).await;
let response = active_request_handle.request(method, params).await;
// TODO: if "no block with that header" or some other jsonrpc errors, skip this response?
response
}
pub async fn try_send_requests(
/// Send the same request to all the handles. Returning the fastest successful result.
pub async fn try_send_parallel_requests(
self: Arc<Self>,
connections: Vec<ActiveRequestHandle>,
active_request_handles: Vec<ActiveRequestHandle>,
method: String,
params: Box<RawValue>,
response_sender: flume::Sender<anyhow::Result<Box<RawValue>>>,
) -> anyhow::Result<()> {
let mut unordered_futures = FuturesUnordered::new();
for connection in connections {
for connection in active_request_handles {
// clone things so we can pass them to a future
let connections = self.clone();
let method = method.clone();
@ -150,7 +151,7 @@ impl Web3Connections {
unordered_futures.push(handle);
}
// TODO: use iterators instead of pushing into a vec
// TODO: use iterators instead of pushing into a vec?
let mut errs = vec![];
if let Some(x) = unordered_futures.next().await {
match x.unwrap() {

211
web3-proxy/src/jsonrpc.rs Normal file

@ -0,0 +1,211 @@
use serde::de::{self, Deserialize, Deserializer, MapAccess, SeqAccess, Visitor};
use serde::Serialize;
use serde_json::value::RawValue;
use std::fmt;
#[derive(Clone, serde::Deserialize)]
pub struct JsonRpcRequest {
// TODO: skip jsonrpc entireley?
// pub jsonrpc: Box<RawValue>,
pub id: Box<RawValue>,
pub method: String,
pub params: Box<RawValue>,
}
impl fmt::Debug for JsonRpcRequest {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
// TODO: the default formatter takes forever to write. this is too quiet though
f.debug_struct("JsonRpcRequest")
.field("id", &self.id)
.field("method", &self.method)
.field("params", &self.params)
.finish()
}
}
/// Requests can come in multiple formats
#[derive(Debug)]
pub enum JsonRpcRequestEnum {
Batch(Vec<JsonRpcRequest>),
Single(JsonRpcRequest),
}
impl<'de> Deserialize<'de> for JsonRpcRequestEnum {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
#[derive(serde::Deserialize)]
#[serde(field_identifier, rename_all = "lowercase")]
enum Field {
JsonRpc,
Id,
Method,
Params,
// TODO: jsonrpc here, too?
}
struct JsonRpcBatchVisitor;
impl<'de> Visitor<'de> for JsonRpcBatchVisitor {
type Value = JsonRpcRequestEnum;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("JsonRpcRequestEnum")
}
fn visit_seq<V>(self, mut seq: V) -> Result<JsonRpcRequestEnum, V::Error>
where
V: SeqAccess<'de>,
{
// TODO: what size should we use as the default?
let mut batch: Vec<JsonRpcRequest> =
Vec::with_capacity(seq.size_hint().unwrap_or(10));
// this was easier than expected
while let Ok(Some(s)) = seq.next_element::<JsonRpcRequest>() {
batch.push(s);
}
Ok(JsonRpcRequestEnum::Batch(batch))
}
fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error>
where
A: MapAccess<'de>,
{
// TODO: i feel like this should be easier
let mut id = None;
let mut method = None;
let mut params = None;
while let Some(key) = map.next_key()? {
match key {
Field::JsonRpc => {
// throw away the value
let foo: String = map.next_value()?;
}
Field::Id => {
if id.is_some() {
return Err(de::Error::duplicate_field("id"));
}
id = Some(map.next_value()?);
}
Field::Method => {
if method.is_some() {
return Err(de::Error::duplicate_field("method"));
}
method = Some(map.next_value()?);
}
Field::Params => {
if params.is_some() {
return Err(de::Error::duplicate_field("params"));
}
params = Some(map.next_value()?);
}
}
}
let id = id.ok_or_else(|| de::Error::missing_field("id"))?;
let method = method.ok_or_else(|| de::Error::missing_field("method"))?;
let params = params.ok_or_else(|| de::Error::missing_field("params"))?;
let single = JsonRpcRequest { id, method, params };
Ok(JsonRpcRequestEnum::Single(single))
}
}
let batch_visitor = JsonRpcBatchVisitor {};
deserializer.deserialize_any(batch_visitor)
}
}
/// All jsonrpc errors use this structure
#[derive(Serialize, Clone)]
pub struct JsonRpcErrorData {
/// The error code
pub code: i64,
/// The error message
pub message: String,
/// Additional data
#[serde(skip_serializing_if = "Option::is_none")]
pub data: Option<serde_json::Value>,
}
/// A complete response
#[derive(Clone, Serialize)]
pub struct JsonRpcForwardedResponse {
pub jsonrpc: String,
pub id: Box<RawValue>,
#[serde(skip_serializing_if = "Option::is_none")]
pub result: Option<Box<RawValue>>,
#[serde(skip_serializing_if = "Option::is_none")]
pub error: Option<JsonRpcErrorData>,
}
/// TODO: the default formatter takes forever to write. this is too quiet though
impl fmt::Debug for JsonRpcForwardedResponse {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("JsonRpcForwardedResponse")
.field("id", &self.id)
.finish_non_exhaustive()
}
}
/// JSONRPC Responses can include one or many response objects.
#[derive(Clone, Serialize)]
#[serde(untagged)]
pub enum JsonRpcForwardedResponseEnum {
Single(JsonRpcForwardedResponse),
Batch(Vec<JsonRpcForwardedResponse>),
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn this_deserialize_single() {
let input = r#"{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}"#;
// test deserializing it directly to a single request object
let output: JsonRpcRequest = serde_json::from_str(input).unwrap();
assert_eq!(output.id.to_string(), "1");
assert_eq!(output.method, "eth_blockNumber");
assert_eq!(output.params.to_string(), "[]");
// test deserializing it into an enum
let output: JsonRpcRequestEnum = serde_json::from_str(input).unwrap();
assert!(matches!(output, JsonRpcRequestEnum::Single(_)));
}
#[test]
fn this_deserialize_batch() {
let input = r#"[{"jsonrpc":"2.0","method":"eth_getCode","params":["0x5ba1e12693dc8f9c48aad8770482f4739beed696","0xe0e6a4"],"id":27},{"jsonrpc":"2.0","method":"eth_getTransactionCount","params":["0x5ba1e12693dc8f9c48aad8770482f4739beed696","0xe0e6a4"],"id":28},{"jsonrpc":"2.0","method":"eth_getBalance","params":["0x5ba1e12693dc8f9c48aad8770482f4739beed696","0xe0e6a4"],"id":29}]"#;
// test deserializing it directly to a batch of request objects
let output: Vec<JsonRpcRequest> = serde_json::from_str(input).unwrap();
assert_eq!(output.len(), 3);
assert_eq!(output[0].id.to_string(), "27");
assert_eq!(output[0].method, "eth_getCode");
assert_eq!(
output[0].params.to_string(),
r#"["0x5ba1e12693dc8f9c48aad8770482f4739beed696","0xe0e6a4"]"#
);
assert_eq!(output[1].id.to_string(), "28");
assert_eq!(output[2].id.to_string(), "29");
// test deserializing it into an enum
let output: JsonRpcRequestEnum = serde_json::from_str(input).unwrap();
assert!(matches!(output, JsonRpcRequestEnum::Batch(_)));
assert_eq!(0, 1);
}
}

@ -1,365 +1,27 @@
mod app;
mod config;
mod connection;
mod connections;
mod jsonrpc;
use config::Web3ConnectionConfig;
use connection::JsonRpcErrorData;
use connection::JsonRpcForwardedResponse;
use ethers::prelude::ProviderError;
use ethers::prelude::{HttpClientError, WsClientError};
// use ethers::providers::transports::common::JsonRpcError;
use futures::future;
use governor::clock::{Clock, QuantaClock};
use linkedhashmap::LinkedHashMap;
use std::fmt;
use std::fs;
use std::sync::atomic::{self, AtomicU64};
use std::sync::Arc;
use std::time::Duration;
use tokio::sync::RwLock;
use tokio::time::sleep;
use tracing::{info, warn};
use tracing::{info, trace, warn};
use warp::Filter;
use warp::Reply;
use crate::app::Web3ProxyApp;
use crate::config::{CliConfig, RpcConfig};
use crate::connection::JsonRpcRequest;
use crate::connections::Web3Connections;
static APP_USER_AGENT: &str = concat!(
"satoshiandkin/",
env!("CARGO_PKG_NAME"),
"/",
env!("CARGO_PKG_VERSION"),
);
// TODO: put this in config? what size should we do?
const RESPONSE_CACHE_CAP: usize = 1024;
/// TODO: these types are probably very bad keys and values. i couldn't get caching of warp::reply::Json to work
type ResponseLruCache = RwLock<LinkedHashMap<(u64, String, String), JsonRpcForwardedResponse>>;
/// The application
// TODO: this debug impl is way too verbose. make something smaller
// TODO: if Web3ProxyApp is always in an Arc, i think we can avoid having at least some of these internal things in arcs
pub struct Web3ProxyApp {
best_head_block_number: Arc<AtomicU64>,
/// clock used for rate limiting
/// TODO: use tokio's clock (will require a different ratelimiting crate)
clock: QuantaClock,
/// Send requests to the best server available
balanced_rpc_tiers: Vec<Arc<Web3Connections>>,
/// Send private requests (like eth_sendRawTransaction) to all these servers
private_rpcs: Option<Arc<Web3Connections>>,
response_cache: ResponseLruCache,
}
impl fmt::Debug for Web3ProxyApp {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
// TODO: the default formatter takes forever to write. this is too quiet though
f.debug_struct("Web3ProxyApp")
.field(
"best_head_block_number",
&self.best_head_block_number.load(atomic::Ordering::Relaxed),
)
.finish_non_exhaustive()
}
}
impl Web3ProxyApp {
async fn try_new(
balanced_rpc_tiers: Vec<Vec<Web3ConnectionConfig>>,
private_rpcs: Vec<Web3ConnectionConfig>,
) -> anyhow::Result<Web3ProxyApp> {
let clock = QuantaClock::default();
let best_head_block_number = Arc::new(AtomicU64::new(0));
// make a http shared client
// TODO: how should we configure the connection pool?
// TODO: 5 minutes is probably long enough. unlimited is a bad idea if something is wrong with the remote server
let http_client = reqwest::ClientBuilder::new()
.connect_timeout(Duration::from_secs(5))
.timeout(Duration::from_secs(300))
.user_agent(APP_USER_AGENT)
.build()?;
// TODO: attach context to this error
let balanced_rpc_tiers =
future::join_all(balanced_rpc_tiers.into_iter().map(|balanced_rpc_tier| {
Web3Connections::try_new(
best_head_block_number.clone(),
balanced_rpc_tier,
Some(http_client.clone()),
&clock,
)
}))
.await
.into_iter()
.collect::<anyhow::Result<Vec<Arc<Web3Connections>>>>()?;
// TODO: attach context to this error
let private_rpcs = if private_rpcs.is_empty() {
warn!("No private relays configured. Any transactions will be broadcast to the public mempool!");
// TODO: instead of None, set it to a list of all the rpcs from balanced_rpc_tiers. that way we broadcast very loudly
None
} else {
Some(
Web3Connections::try_new(
best_head_block_number.clone(),
private_rpcs,
Some(http_client),
&clock,
)
.await?,
)
};
Ok(Web3ProxyApp {
best_head_block_number,
clock,
balanced_rpc_tiers,
private_rpcs,
response_cache: Default::default(),
})
}
/// send the request to the approriate RPCs
/// TODO: dry this up
async fn proxy_web3_rpc(
self: Arc<Web3ProxyApp>,
json_body: JsonRpcRequest,
) -> anyhow::Result<impl warp::Reply> {
if self.private_rpcs.is_some() && json_body.method == "eth_sendRawTransaction" {
let private_rpcs = self.private_rpcs.as_ref().unwrap();
// there are private rpcs configured and the request is eth_sendSignedTransaction. send to all private rpcs
loop {
// TODO: think more about this lock. i think it won't actually help the herd. it probably makes it worse if we have a tight lag_limit
match private_rpcs.get_upstream_servers() {
Ok(upstream_servers) => {
let (tx, rx) = flume::unbounded();
let connections = private_rpcs.clone();
let method = json_body.method.clone();
let params = json_body.params.clone();
// TODO: benchmark this compared to waiting on unbounded futures
tokio::spawn(async move {
connections
.try_send_requests(upstream_servers, method, params, tx)
.await
});
// wait for the first response
let backend_response = rx.recv_async().await?;
if let Ok(backend_response) = backend_response {
// TODO: i think we
let response = JsonRpcForwardedResponse {
jsonrpc: "2.0".to_string(),
id: json_body.id,
result: Some(backend_response),
error: None,
};
return Ok(warp::reply::json(&response));
}
}
Err(not_until) => {
// TODO: move this to a helper function
// sleep (with a lock) until our rate limits should be available
if let Some(not_until) = not_until {
let deadline = not_until.wait_time_from(self.clock.now());
sleep(deadline).await;
}
}
};
}
} else {
// this is not a private transaction (or no private relays are configured)
// try to send to each tier, stopping at the first success
// if no tiers are synced, fallback to privates
loop {
// there are multiple tiers. save the earliest not_until (if any). if we don't return, we will sleep until then and then try again
let mut earliest_not_until = None;
// TODO: how can we better build this iterator?
let rpc_iter = if let Some(private_rpcs) = self.private_rpcs.as_ref() {
self.balanced_rpc_tiers.iter().chain(vec![private_rpcs])
} else {
self.balanced_rpc_tiers.iter().chain(vec![])
};
for balanced_rpcs in rpc_iter {
let best_head_block_number =
self.best_head_block_number.load(atomic::Ordering::Acquire); // TODO: we don't store current block for everything anymore. we store it on the connections
let best_rpc_block_number = balanced_rpcs.head_block_number();
if best_rpc_block_number < best_head_block_number {
continue;
}
// TODO: building this cache key is slow and its large, but i don't see a better way right now
// TODO: inspect the params and see if a block is specified. if so, use that block number instead of current_block
let cache_key = (
best_head_block_number,
json_body.method.clone(),
json_body.params.to_string(),
);
if let Some(cached) = self.response_cache.read().await.get(&cache_key) {
// TODO: this still serializes every time
return Ok(warp::reply::json(cached));
}
// TODO: what allowed lag?
match balanced_rpcs.next_upstream_server().await {
Ok(upstream_server) => {
let response = balanced_rpcs
.try_send_request(
upstream_server,
&json_body.method,
&json_body.params,
)
.await;
let response = match response {
Ok(partial_response) => {
// TODO: trace here was really slow with millions of requests.
// info!("forwarding request from {}", upstream_server);
let response = JsonRpcForwardedResponse {
jsonrpc: "2.0".to_string(),
id: json_body.id,
// TODO: since we only use the result here, should that be all we return from try_send_request?
result: Some(partial_response),
error: None,
};
// TODO: small race condidition here. parallel requests with the same query will both be saved to the cache
let mut response_cache = self.response_cache.write().await;
// TODO: cache the warp::reply to save us serializing every time
response_cache.insert(cache_key, response.clone());
if response_cache.len() >= RESPONSE_CACHE_CAP {
response_cache.pop_front();
}
response
}
Err(e) => {
let code;
let message: String;
let data;
match e {
ProviderError::JsonRpcClientError(e) => {
// TODO: we should check what type the provider is rather than trying to downcast both types of errors
if let Some(e) = e.downcast_ref::<HttpClientError>() {
match &*e {
HttpClientError::JsonRpcError(e) => {
code = e.code;
message = e.message.clone();
data = e.data.clone();
}
e => {
// TODO: improve this
code = -32603;
message = format!("{}", e);
data = None;
}
}
} else if let Some(e) =
e.downcast_ref::<WsClientError>()
{
match &*e {
WsClientError::JsonRpcError(e) => {
code = e.code;
message = e.message.clone();
data = e.data.clone();
}
e => {
// TODO: improve this
code = -32603;
message = format!("{}", e);
data = None;
}
}
} else {
unimplemented!();
}
}
_ => {
code = -32603;
message = format!("{}", e);
data = None;
}
}
JsonRpcForwardedResponse {
jsonrpc: "2.0".to_string(),
id: json_body.id,
result: None,
error: Some(JsonRpcErrorData {
code,
message,
data,
}),
}
}
};
return Ok(warp::reply::json(&response));
}
Err(None) => {
// TODO: this is too verbose. if there are other servers in other tiers, we use those!
// warn!("No servers in sync!");
}
Err(Some(not_until)) => {
// save the smallest not_until. if nothing succeeds, return an Err with not_until in it
// TODO: helper function for this
if earliest_not_until.is_none() {
earliest_not_until.replace(not_until);
} else {
let earliest_possible =
earliest_not_until.as_ref().unwrap().earliest_possible();
let new_earliest_possible = not_until.earliest_possible();
if earliest_possible > new_earliest_possible {
earliest_not_until = Some(not_until);
}
}
}
}
}
// we haven't returned an Ok
// if we did return a rate limit error, sleep and try again
if let Some(earliest_not_until) = earliest_not_until {
let deadline = earliest_not_until.wait_time_from(self.clock.now());
sleep(deadline).await;
} else {
// TODO: how long should we wait?
// TODO: max wait time?
warn!("No servers in sync!");
// TODO: return json error? return a 502?
return Err(anyhow::anyhow!("no servers in sync"));
};
}
}
}
}
#[tokio::main]
async fn main() -> anyhow::Result<()> {
// install global collector configured based on RUST_LOG env var.
tracing_subscriber::fmt::init();
info!("test info");
warn!("test warn");
trace!("test trace");
let cli_config: CliConfig = argh::from_env();
info!("Loading rpc config @ {}", cli_config.rpc_config_path);
@ -391,14 +53,14 @@ async fn main() -> anyhow::Result<()> {
Ok(())
}
/// convert result into an http response. use this at the end of your warp filter
/// TODO: using boxes can't be the best way. think about this more
/// convert result into a jsonrpc error. use this at the end of your warp filter
fn handle_anyhow_errors<T: warp::Reply>(
res: anyhow::Result<T>,
) -> warp::http::Response<warp::hyper::Body> {
match res {
Ok(r) => r.into_response(),
Err(e) => warp::reply::with_status(
// TODO: json error
format!("{}", e),
warp::http::StatusCode::INTERNAL_SERVER_ERROR,
)