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package integration_tests
import (
"fmt"
"net/http"
"os"
"sync/atomic"
"testing"
"time"
"github.com/alicebob/miniredis"
"github.com/ethereum-optimism/optimism/proxyd"
"github.com/stretchr/testify/require"
)
const (
goodResponse = `{"jsonrpc": "2.0", "result": "hello", "id": 999}`
noBackendsResponse = `{"error":{"code":-32011,"message":"no backends available for method"},"id":999,"jsonrpc":"2.0"}`
unexpectedResponse = `{"error":{"code":-32011,"message":"some error"},"id":999,"jsonrpc":"2.0"}`
)
func TestFailover(t *testing.T) {
goodBackend := NewMockBackend(BatchedResponseHandler(200, goodResponse))
defer goodBackend.Close()
badBackend := NewMockBackend(nil)
defer badBackend.Close()
require.NoError(t, os.Setenv("GOOD_BACKEND_RPC_URL", goodBackend.URL()))
require.NoError(t, os.Setenv("BAD_BACKEND_RPC_URL", badBackend.URL()))
config := ReadConfig("failover")
client := NewProxydClient("http://127.0.0.1:8545")
_, shutdown, err := proxyd.Start(config)
require.NoError(t, err)
defer shutdown()
tests := []struct {
name string
handler http.Handler
}{
{
"backend responds 200 with non-JSON response",
http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(200)
_, _ = w.Write([]byte("this data is not JSON!"))
}),
},
{
"backend responds with no body",
http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(200)
}),
},
}
codes := []int{
300,
301,
302,
401,
403,
429,
500,
503,
}
for _, code := range codes {
tests = append(tests, struct {
name string
handler http.Handler
}{
fmt.Sprintf("backend %d", code),
http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(code)
}),
})
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
badBackend.SetHandler(tt.handler)
res, statusCode, err := client.SendRPC("eth_chainId", nil)
require.NoError(t, err)
require.Equal(t, 200, statusCode)
RequireEqualJSON(t, []byte(goodResponse), res)
require.Equal(t, 1, len(badBackend.Requests()))
require.Equal(t, 1, len(goodBackend.Requests()))
badBackend.Reset()
goodBackend.Reset()
})
}
t.Run("backend times out and falls back to another", func(t *testing.T) {
badBackend.SetHandler(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
time.Sleep(2 * time.Second)
_, _ = w.Write([]byte("[{}]"))
}))
res, statusCode, err := client.SendRPC("eth_chainId", nil)
require.NoError(t, err)
require.Equal(t, 200, statusCode)
RequireEqualJSON(t, []byte(goodResponse), res)
require.Equal(t, 1, len(badBackend.Requests()))
require.Equal(t, 1, len(goodBackend.Requests()))
goodBackend.Reset()
badBackend.Reset()
})
t.Run("works with a batch request", func(t *testing.T) {
goodBackend.SetHandler(BatchedResponseHandler(200, goodResponse, goodResponse))
badBackend.SetHandler(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(500)
}))
res, statusCode, err := client.SendBatchRPC(
NewRPCReq("1", "eth_chainId", nil),
NewRPCReq("2", "eth_chainId", nil),
)
require.NoError(t, err)
require.Equal(t, 200, statusCode)
RequireEqualJSON(t, []byte(asArray(goodResponse, goodResponse)), res)
require.Equal(t, 1, len(badBackend.Requests()))
require.Equal(t, 1, len(goodBackend.Requests()))
goodBackend.Reset()
badBackend.Reset()
})
}
func TestRetries(t *testing.T) {
backend := NewMockBackend(BatchedResponseHandler(200, goodResponse))
defer backend.Close()
require.NoError(t, os.Setenv("GOOD_BACKEND_RPC_URL", backend.URL()))
config := ReadConfig("retries")
client := NewProxydClient("http://127.0.0.1:8545")
_, shutdown, err := proxyd.Start(config)
require.NoError(t, err)
defer shutdown()
attempts := int32(0)
backend.SetHandler(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
incremented := atomic.AddInt32(&attempts, 1)
if incremented != 2 {
w.WriteHeader(500)
return
}
BatchedResponseHandler(200, goodResponse)(w, r)
}))
// test case where request eventually succeeds
res, statusCode, err := client.SendRPC("eth_chainId", nil)
require.NoError(t, err)
require.Equal(t, 200, statusCode)
RequireEqualJSON(t, []byte(goodResponse), res)
require.Equal(t, 2, len(backend.Requests()))
// test case where it does not
backend.Reset()
attempts = -10
res, statusCode, err = client.SendRPC("eth_chainId", nil)
require.NoError(t, err)
require.Equal(t, 503, statusCode)
RequireEqualJSON(t, []byte(noBackendsResponse), res)
require.Equal(t, 4, len(backend.Requests()))
}
func TestOutOfServiceInterval(t *testing.T) {
okHandler := BatchedResponseHandler(200, goodResponse)
goodBackend := NewMockBackend(okHandler)
defer goodBackend.Close()
badBackend := NewMockBackend(nil)
defer badBackend.Close()
require.NoError(t, os.Setenv("GOOD_BACKEND_RPC_URL", goodBackend.URL()))
require.NoError(t, os.Setenv("BAD_BACKEND_RPC_URL", badBackend.URL()))
config := ReadConfig("out_of_service_interval")
client := NewProxydClient("http://127.0.0.1:8545")
_, shutdown, err := proxyd.Start(config)
require.NoError(t, err)
defer shutdown()
badBackend.SetHandler(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(503)
}))
res, statusCode, err := client.SendRPC("eth_chainId", nil)
require.NoError(t, err)
require.Equal(t, 200, statusCode)
RequireEqualJSON(t, []byte(goodResponse), res)
require.Equal(t, 2, len(badBackend.Requests()))
require.Equal(t, 1, len(goodBackend.Requests()))
res, statusCode, err = client.SendRPC("eth_chainId", nil)
require.NoError(t, err)
require.Equal(t, 200, statusCode)
RequireEqualJSON(t, []byte(goodResponse), res)
require.Equal(t, 4, len(badBackend.Requests()))
require.Equal(t, 2, len(goodBackend.Requests()))
_, statusCode, err = client.SendBatchRPC(
NewRPCReq("1", "eth_chainId", nil),
NewRPCReq("1", "eth_chainId", nil),
)
require.NoError(t, err)
require.Equal(t, 200, statusCode)
require.Equal(t, 8, len(badBackend.Requests()))
require.Equal(t, 4, len(goodBackend.Requests()))
time.Sleep(time.Second)
badBackend.SetHandler(okHandler)
res, statusCode, err = client.SendRPC("eth_chainId", nil)
require.NoError(t, err)
require.Equal(t, 200, statusCode)
RequireEqualJSON(t, []byte(goodResponse), res)
require.Equal(t, 9, len(badBackend.Requests()))
require.Equal(t, 4, len(goodBackend.Requests()))
}
func TestBatchWithPartialFailover(t *testing.T) {
config := ReadConfig("failover")
config.Server.MaxUpstreamBatchSize = 2
goodBackend := NewMockBackend(BatchedResponseHandler(200, goodResponse, goodResponse))
defer goodBackend.Close()
badBackend := NewMockBackend(SingleResponseHandler(200, "this data is not JSON!"))
defer badBackend.Close()
require.NoError(t, os.Setenv("GOOD_BACKEND_RPC_URL", goodBackend.URL()))
require.NoError(t, os.Setenv("BAD_BACKEND_RPC_URL", badBackend.URL()))
client := NewProxydClient("http://127.0.0.1:8545")
_, shutdown, err := proxyd.Start(config)
require.NoError(t, err)
defer shutdown()
res, statusCode, err := client.SendBatchRPC(
NewRPCReq("1", "eth_chainId", nil),
NewRPCReq("2", "eth_chainId", nil),
NewRPCReq("3", "eth_chainId", nil),
NewRPCReq("4", "eth_chainId", nil),
)
require.NoError(t, err)
require.Equal(t, 200, statusCode)
RequireEqualJSON(t, []byte(asArray(goodResponse, goodResponse, goodResponse, goodResponse)), res)
require.Equal(t, 2, len(badBackend.Requests()))
require.Equal(t, 2, len(goodBackend.Requests()))
}
func TestInfuraFailoverOnUnexpectedResponse(t *testing.T) {
InitLogger()
// Scenario:
// 1. Send batch to BAD_BACKEND (Infura)
// 2. Infura fails completely due to a partially errorneous batch request (one of N+1 request object is invalid)
// 3. Assert that the request batch is re-routed to the failover provider
// 4. Assert that BAD_BACKEND is NOT labeled offline
// 5. Assert that BAD_BACKEND is NOT retried
redis, err := miniredis.Run()
require.NoError(t, err)
defer redis.Close()
config := ReadConfig("failover")
config.Server.MaxUpstreamBatchSize = 2
config.BackendOptions.MaxRetries = 2
// Setup redis to detect offline backends
config.Redis.URL = fmt.Sprintf("redis://127.0.0.1:%s", redis.Port())
require.NoError(t, err)
goodBackend := NewMockBackend(BatchedResponseHandler(200, goodResponse, goodResponse))
defer goodBackend.Close()
badBackend := NewMockBackend(SingleResponseHandler(200, unexpectedResponse))
defer badBackend.Close()
require.NoError(t, os.Setenv("GOOD_BACKEND_RPC_URL", goodBackend.URL()))
require.NoError(t, os.Setenv("BAD_BACKEND_RPC_URL", badBackend.URL()))
client := NewProxydClient("http://127.0.0.1:8545")
_, shutdown, err := proxyd.Start(config)
require.NoError(t, err)
defer shutdown()
res, statusCode, err := client.SendBatchRPC(
NewRPCReq("1", "eth_chainId", nil),
NewRPCReq("2", "eth_chainId", nil),
)
require.NoError(t, err)
require.Equal(t, 200, statusCode)
RequireEqualJSON(t, []byte(asArray(goodResponse, goodResponse)), res)
require.Equal(t, 1, len(badBackend.Requests()))
require.Equal(t, 1, len(goodBackend.Requests()))
}