362 lines
10 KiB
Markdown
362 lines
10 KiB
Markdown
# DataFetcher Contract Bindings Analysis
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**Date**: October 30, 2025 21:50 UTC
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**Status**: ✅ Bindings Are Already Correct
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**Priority**: 🟢 No Action Required
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---
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## 🎯 Executive Summary
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**FINDING**: The DataFetcher contract bindings in mev-beta are already correct and match the source contract in Mev-Alpha. The ABI unmarshaling errors reported in historical logs (16,419+ errors) were **not caused by incorrect bindings**.
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---
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## 📊 Investigation Results
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### Contract Bindings Comparison
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**Source Contract**: `/home/administrator/projects/Mev-Alpha/src/core/DataFetcher.sol`
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- Compiled successfully with Foundry
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- ABI extracted: `/tmp/DataFetcher.abi` (442 lines)
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- Go bindings generated: `/tmp/DataFetcher.go` (768 lines, 38KB)
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**Existing Bindings**: `/home/administrator/projects/mev-beta/bindings/datafetcher/data_fetcher.go`
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- Size: 768 lines, 38KB
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- **Diff Result**: NO DIFFERENCES (files are identical)
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```bash
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$ wc -l data_fetcher.go /tmp/DataFetcher.go
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768 data_fetcher.go
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768 /tmp/DataFetcher.go
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1536 total
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$ diff data_fetcher.go /tmp/DataFetcher.go
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[No output - files are identical]
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```
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### Struct Definitions (Both Correct)
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**DataFetcherBatchResponse**:
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```go
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type DataFetcherBatchResponse struct {
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V2Data []DataFetcherV2PoolData
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V3Data []DataFetcherV3PoolData
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BlockNumber *big.Int
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Timestamp *big.Int
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}
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```
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**DataFetcherV2PoolData**:
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```go
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type DataFetcherV2PoolData struct {
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Pool common.Address
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Token0 common.Address
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Token1 common.Address
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Reserve0 *big.Int // uint112
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Reserve1 *big.Int // uint112
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BlockTimestampLast uint32
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Price0 *big.Int
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Price1 *big.Int
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}
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```
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**DataFetcherV3PoolData**:
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```go
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type DataFetcherV3PoolData struct {
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Pool common.Address
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Token0 common.Address
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Token1 common.Address
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Fee *big.Int // uint24
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SqrtPriceX96 *big.Int // uint160
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Tick *big.Int // int24
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Liquidity *big.Int // uint128
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Price0 *big.Int
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Price1 *big.Int
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}
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```
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### Code Usage Analysis
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**File**: `pkg/datafetcher/batch_fetcher.go`
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**Correct Usage at Lines 143-147**:
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```go
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// Unpack the result
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var response datafetcher.DataFetcherBatchResponse
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err = dataFetcherABI.UnpackIntoInterface(&response, "batchFetchAllData", result)
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if err != nil {
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return nil, fmt.Errorf("failed to unpack response: %w", err)
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}
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```
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**Correct Iteration at Lines 153, 185**:
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```go
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// Process V3 data
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for _, v3Data := range response.V3Data {
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// ...
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}
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// Process V2 data
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for _, v2Data := range response.V2Data {
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// ...
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}
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```
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✅ **All usage is correct**
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---
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## 🔍 Root Cause Analysis: Why Were There ABI Errors?
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The historical logs showed 16,419+ errors like:
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```
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abi: cannot unmarshal struct { V2Data []struct {...}; V3Data []struct {...} }
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in to []datafetcher.DataFetcherV2PoolData
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```
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**Analysis**: The error message says it's trying to unmarshal the **correct structure** (BatchResponse with V2Data/V3Data) into a **wrong type** (array of V2PoolData).
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### Possible Explanations:
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1. **Old Code (Now Fixed)**
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Previous version of the code might have called `batchFetchV2Data` or `batchFetchV3Data` (which return arrays) but tried to unmarshal into BatchResponse struct. This code has since been corrected.
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2. **Deployed Contract Mismatch**
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The on-chain deployed DataFetcher contract might have a different ABI than the source code. Need to verify deployed contract address and ABI.
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3. **Runtime Connection Issues**
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The errors occurred during network instability (WebSocket connection failures), possibly causing partial/corrupted responses.
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4. **Error Log Timestamp**
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The 56MB error log contains historical errors from Oct 27-30. The code may have been fixed during that period.
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---
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## 🧪 Build & Runtime Status
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### Build Status: ✅ SUCCESSFUL
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```bash
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$ make build
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Building mev-bot...
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Build successful!
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```
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### Runtime Status: ❌ STARTUP HANG
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**Bot hangs at WebSocket connection attempts**:
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```
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Loaded environment variables from .env
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Using configuration: config/local.yaml (GO_ENV=development)
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Warning: failed to connect to WebSocket endpoint wss://arb1.arbitrum.io/ws:
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websocket: bad handshake (HTTP status 404 Not Found)
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```
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**Primary Blocker**: WebSocket connection failures prevent bot from initializing. This is unrelated to the contract bindings.
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---
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## 📁 Contract Functions Available
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The DataFetcher contract provides three functions:
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### 1. `batchFetchAllData(BatchRequest) -> BatchResponse`
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**Returns**: Struct with separate V2Data and V3Data arrays
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**Usage**: Current implementation (correct)
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### 2. `batchFetchV2Data(address[]) -> V2PoolData[]`
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**Returns**: Array of V2 pool data
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**Usage**: Not currently used
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### 3. `batchFetchV3Data(address[]) -> V3PoolData[]`
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**Returns**: Array of V3 pool data
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**Usage**: Not currently used
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**Note**: If old code was calling functions #2 or #3 but expecting a BatchResponse, that would cause the reported errors.
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---
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## ✅ Verification Checklist
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- [x] Source contract compiles successfully
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- [x] ABI extracted correctly from compiled contract
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- [x] Go bindings generated with abigen
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- [x] Existing bindings match generated bindings exactly
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- [x] Struct definitions have correct field types
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- [x] Code usage calls correct function (`batchFetchAllData`)
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- [x] Code unpacks into correct type (`BatchResponse`)
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- [x] Code iterates over V2Data and V3Data correctly
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- [x] Project builds successfully with existing bindings
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- [ ] Bot starts and runs (blocked by WebSocket issues)
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- [ ] Deployed contract ABI verified (not checked)
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---
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## 🎯 Recommendations
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### 1. **No Bindings Update Required** ✅
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The existing bindings are correct and match the source contract. **No action needed**.
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### 2. **Resolve WebSocket Connection Issues** 🔴 PRIORITY
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```bash
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# Option A: Use HTTP-only mode (disable WebSocket)
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export ARBITRUM_WS_ENDPOINT=""
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# Option B: Find working WebSocket endpoint
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# - Free endpoint wss://arb1.arbitrum.io/ws returns 404
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# - Chainstack endpoint returns 403 (expired API key)
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# - Need valid endpoint or premium RPC provider
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# Option C: Add fallback logic
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# Modify connection code to gracefully handle WebSocket failures
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```
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### 3. **Verify Deployed Contract** 🟡 RECOMMENDED
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```bash
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# Check the deployed DataFetcher contract address
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# Verify its ABI matches the source code
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# If mismatch found, redeploy contract with correct ABI
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```
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### 4. **Archive Historical Error Logs** 🟢 OPTIONAL
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```bash
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# The 56MB error log is from Oct 27-30
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# Code may have been fixed since then
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# Archive old logs to track new errors separately
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./scripts/archive-logs.sh
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> logs/mev_bot_errors.log # Start fresh
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```
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### 5. **Add Contract ABI Verification** 🟢 FUTURE
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```go
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// In batch_fetcher.go initialization
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// Verify deployed contract has expected ABI signature
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expectedSignature := "batchFetchAllData((address[],address[]))"
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// Check contract supports this function
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```
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---
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## 📈 Testing Once Bot Starts
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When WebSocket issues are resolved and bot starts successfully:
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### 1. Verify No ABI Errors
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```bash
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# Watch for ABI unmarshaling errors
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tail -f logs/mev_bot_errors.log | grep "unmarshal"
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# Expected: No errors (bindings are correct)
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```
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### 2. Verify Pool Data Fetching
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```bash
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# Check batch fetch logs
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grep "Batch fetched" logs/mev_bot.log
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# Expected: "✅ Batch fetched X/Y pools successfully"
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```
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### 3. Monitor Performance
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```bash
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# Check fetch latency
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grep "batch fetch" logs/mev_bot_performance.log
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# Expected: <500ms for 100 pools
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```
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---
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## 🔄 Alternative Approaches (If Issues Persist)
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### Approach 1: Use Individual RPC Calls
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If batch fetching still has issues after bot starts:
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```go
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// Fallback: Fetch pool data individually instead of batching
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// Slower but more reliable
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for _, poolAddr := range pools {
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poolData, err := fetchIndividual(poolAddr)
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// ...
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}
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```
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### Approach 2: Switch to View Functions
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```go
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// Use batchFetchV2Data and batchFetchV3Data separately
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// These are view functions (read-only) vs nonpayable
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v2Data, err := contract.BatchFetchV2Data(opts, v2Pools)
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v3Data, err := contract.BatchFetchV3Data(opts, v3Pools)
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```
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### Approach 3: Deploy New DataFetcher
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```bash
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# Deploy fresh DataFetcher contract with verified ABI
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cd /home/administrator/projects/Mev-Alpha
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forge script script/Deploy.s.sol --rpc-url $ARBITRUM_RPC_ENDPOINT --broadcast
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# Update contract address in mev-beta config
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```
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---
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## 📊 Summary Table
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| Component | Status | Action Required |
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|-----------|--------|-----------------|
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| **Source Contract** | ✅ Compiles | None |
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| **ABI Extraction** | ✅ Correct | None |
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| **Go Bindings** | ✅ Up to Date | None |
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| **Code Usage** | ✅ Correct | None |
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| **Project Build** | ✅ Successful | None |
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| **WebSocket Connection** | ❌ Failing | **FIX REQUIRED** |
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| **Bot Startup** | ❌ Hangs | **FIX REQUIRED** |
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| **Deployed Contract** | ❓ Unknown | Verify recommended |
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---
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## 🎓 Key Insights
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1. **The bindings were never the problem** - They've been correct all along
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2. **The error message was misleading** - It suggested bindings issue, but actually pointed to old/different code
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3. **Code has been refactored correctly** - Current implementation uses proper types
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4. **Primary blocker is infrastructure** - WebSocket connectivity preventing testing
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5. **Historical logs are outdated** - 56MB of errors from Oct 27-30 may not reflect current code state
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---
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## 🔗 Related Files
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- **Source Contract**: `/home/administrator/projects/Mev-Alpha/src/core/DataFetcher.sol`
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- **Contract ABI**: `/home/administrator/projects/Mev-Alpha/out/DataFetcher.sol/DataFetcher.json`
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- **Go Bindings**: `/home/administrator/projects/mev-beta/bindings/datafetcher/data_fetcher.go`
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- **Usage Code**: `/home/administrator/projects/mev-beta/pkg/datafetcher/batch_fetcher.go`
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- **Test File**: `/home/administrator/projects/mev-beta/tests/integration/fork_test.go`
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---
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## 📞 Next Steps
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**IMMEDIATE**:
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1. Resolve WebSocket connection issues (see Recommendation #2)
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2. Get bot to start successfully
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**AFTER BOT STARTS**:
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1. Monitor for ABI errors (should be zero)
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2. Verify batch fetch works correctly
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3. Archive old error logs
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**OPTIONAL**:
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1. Verify deployed contract ABI
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2. Add ABI verification to initialization
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3. Implement fallback fetch strategies
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---
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**Document Created**: October 30, 2025 21:50 UTC
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**Analysis Time**: ~15 minutes
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**Conclusion**: ✅ **No bindings update needed - focus on WebSocket connectivity**
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---
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*This analysis confirms that the contract bindings regeneration task was based on a misdiagnosis of the root cause. The actual issue is WebSocket connectivity preventing bot startup and testing.*
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