Fix pokt-network#1457; Fix pokt-network#1484;

Fix a high memory consumption that also is part of the issue pokt-network#1457.
Under high load of requests (1000/rps or more) the RAM got crazy and scale up to 40GB or close to that.
Now after the fix of pokt-network#1457 with the worker pool, the node remains under 14gb of ram in my local tests.

app/common_test.go

@@ -105,6 +105,7 @@ func NewInMemoryTendermintNodeAminoWithValidators(t *testing.T, genesisState []b
 			panic(err)
 		}
 		pocketTypes.CleanPocketNodes()
+		pocketTypes.StopEvidenceWorker()
 		PCA = nil
 		inMemKB = nil
 		err := inMemDB.Close()
@@ -170,6 +171,7 @@ func NewInMemoryTendermintNodeProtoWithValidators(t *testing.T, genesisState []b
 		}
 
 		pocketTypes.CleanPocketNodes()
+		pocketTypes.StopEvidenceWorker()
 
 		PCA = nil
 		inMemKB = nil

app/config.go

@@ -473,6 +473,7 @@ func InitPocketCoreConfig(chains *types.HostedBlockchains, logger log.Logger) {
 }
 
 func ShutdownPocketCore() {
+	types.StopEvidenceWorker()
 	types.FlushSessionCache()
 	types.StopServiceMetrics()
 }

app/query_test.go

@@ -791,6 +791,7 @@ func TestQueryRelay(t *testing.T) {
 			_, stopCli, evtChan := subscribeTo(t, tmTypes.EventNewBlock)
 			select {
 			case <-evtChan:
+				assert.Equal(t, uint64(1), types.GlobalEvidenceWorker.SuccessfulTasks())
 				inv, err := types.GetEvidence(types.SessionHeader{
 					ApplicationPubKey:  aat.ApplicationPublicKey,
 					Chain:              relay.Proof.Blockchain,
@@ -858,16 +859,18 @@ func TestQueryRelayMultipleNodes(t *testing.T) {
 			}
 			_, stopCli, evtChan := subscribeTo(t, tmTypes.EventNewBlock)
 			<-evtChan // Wait for block
+			chain := sdk.PlaceholderHash
+			sessionBlockHeight := int64(1)
 			// setup relay
 			for _, v := range validators {
 				relay := types.Relay{
 					Payload: payload,
 					Meta:    types.RelayMeta{BlockHeight: 5}, // todo race condition here
 					Proof: types.RelayProof{
 						Entropy:            32598345349034509,
-						SessionBlockHeight: 1,
+						SessionBlockHeight: sessionBlockHeight,
 						ServicerPubKey:     v.PublicKey().RawString(),
-						Blockchain:         sdk.PlaceholderHash,
+						Blockchain:         chain,
 						Token:              aat,
 						Signature:          "",
 					},
@@ -886,23 +889,32 @@ func TestQueryRelayMultipleNodes(t *testing.T) {
 					BodyString(expectedRequest).
 					Reply(200).
 					BodyString(expectedResponse)
+			}
 
-				validatorAddress := sdk.GetAddress(v.PublicKey())
-				node, nodeErr := types.GetPocketNodeByAddress(&validatorAddress)
+			select {
+			case <-evtChan:
+				// verify that each store task was successful
+				assert.Equal(t, uint64(len(validators)), types.GlobalEvidenceWorker.SuccessfulTasks())
+				// check the evidence store of each node.
+				for _, v := range validators {
+					validatorAddress := sdk.GetAddress(v.PublicKey())
+					_node, nodeErr := types.GetPocketNodeByAddress(&validatorAddress)
+
+					assert.Nil(t, nodeErr)
+					inv, err := types.GetEvidence(types.SessionHeader{
+						ApplicationPubKey:  aat.ApplicationPublicKey,
+						Chain:              chain,
+						SessionBlockHeight: sessionBlockHeight,
+					}, types.RelayEvidence, sdk.NewInt(10000), _node.EvidenceStore)
+					assert.Nil(t, err)
+					assert.NotNil(t, inv)
+					assert.Equal(t, int64(1), inv.NumOfProofs)
+				}
 
-				assert.Nil(t, nodeErr)
-				inv, err := types.GetEvidence(types.SessionHeader{
-					ApplicationPubKey:  aat.ApplicationPublicKey,
-					Chain:              relay.Proof.Blockchain,
-					SessionBlockHeight: relay.Proof.SessionBlockHeight,
-				}, types.RelayEvidence, sdk.NewInt(10000), node.EvidenceStore)
-				assert.Nil(t, err)
-				assert.NotNil(t, inv)
-				assert.Equal(t, inv.NumOfProofs, int64(1))
+				cleanup()
+				stopCli()
+				gock.Off()
 			}
-			cleanup()
-			stopCli()
-			gock.Off()
 			return
 		})
 	}

go.mod

@@ -9,6 +9,8 @@ replace github.com/tendermint/tm-db => github.com/pokt-network/tm-db v0.5.2-0.20
 require (
 	github.com/cosmos/gogoproto v1.4.10
 	github.com/cucumber/godog v0.12.5
+	github.com/alitto/pond v1.8.1
+	github.com/cucumber/godog v0.12.6
 	github.com/go-kit/kit v0.12.0
 	github.com/gogo/protobuf v1.3.2
 	github.com/golang/protobuf v1.5.3
@@ -19,7 +21,7 @@ require (
 	github.com/prometheus/client_golang v1.11.0
 	github.com/regen-network/cosmos-proto v0.3.0
 	github.com/spf13/cobra v1.4.0
-	github.com/stretchr/testify v1.7.0
+	github.com/stretchr/testify v1.7.1
 	github.com/syndtr/goleveldb v1.0.1-0.20210819022825-2ae1ddf74ef7
 	github.com/tendermint/go-amino v0.15.1
 	github.com/tendermint/tendermint v0.33.7
@@ -43,7 +45,7 @@ require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/go-kit/log v0.2.0 // indirect
 	github.com/go-logfmt/logfmt v0.5.1 // indirect
-	github.com/gofrs/uuid v4.0.0+incompatible // indirect
+	github.com/gofrs/uuid v4.2.0+incompatible // indirect
 	github.com/golang/snappy v0.0.4 // indirect
 	github.com/google/btree v1.0.0 // indirect
 	github.com/google/go-cmp v0.5.9 // indirect
@@ -52,7 +54,7 @@ require (
 	github.com/gtank/ristretto255 v0.1.2 // indirect
 	github.com/h2non/parth v0.0.0-20190131123155-b4df798d6542 // indirect
 	github.com/hashicorp/go-immutable-radix v1.3.1 // indirect
-	github.com/hashicorp/go-memdb v1.3.0 // indirect
+	github.com/hashicorp/go-memdb v1.3.2 // indirect
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/jmhodges/levigo v1.0.0 // indirect
 	github.com/kr/text v0.2.0 // indirect

types/config.go

@@ -36,6 +36,9 @@ type PocketConfig struct {
 	ValidatorCacheSize         int64  `json:"validator_cache_size"`
 	ApplicationCacheSize       int64  `json:"application_cache_size"`
 	RPCTimeout                 int64  `json:"rpc_timeout"`
+	RPCMaxIdleConns           int    `json:"rpc_max_idle_conns"`
+	RPCMaxConnsPerHost        int    `json:"rpc_max_conns_per_host"`
+	RPCMaxIdleConnsPerHost    int    `json:"rpc_max_idle_conns_per_host"`
 	PrometheusAddr             string `json:"pocket_prometheus_port"`
 	PrometheusMaxOpenfiles     int    `json:"prometheus_max_open_files"`
 	MaxClaimAgeForProofRetry   int    `json:"max_claim_age_for_proof_retry"`
@@ -104,6 +107,9 @@ const (
 	DefaultPocketPrometheusListenAddr  = "8083"
 	DefaultPrometheusMaxOpenFile       = 3
 	DefaultRPCTimeout                  = 30000
+	DefaultRPCMaxIdleConns             = 1000
+	DefaultRPCMaxConnsPerHost          = 1000
+	DefaultRPCMaxIdleConnsPerHost      = 1000
 	DefaultMaxClaimProofRetryAge       = 32
 	DefaultProofPrevalidation          = false
 	DefaultCtxCacheSize                = 20
@@ -138,6 +144,9 @@ func DefaultConfig(dataDir string) Config {
 			ValidatorCacheSize:         DefaultValidatorCacheSize,
 			ApplicationCacheSize:       DefaultApplicationCacheSize,
 			RPCTimeout:                 DefaultRPCTimeout,
+			RPCMaxIdleConns:           DefaultRPCMaxIdleConns,
+			RPCMaxConnsPerHost:        DefaultRPCMaxConnsPerHost,
+			RPCMaxIdleConnsPerHost:    DefaultRPCMaxIdleConnsPerHost,
 			PrometheusAddr:             DefaultPocketPrometheusListenAddr,
 			PrometheusMaxOpenfiles:     DefaultPrometheusMaxOpenFile,
 			MaxClaimAgeForProofRetry:   DefaultMaxClaimProofRetryAge,

x/pocketcore/keeper/service.go

@@ -69,8 +69,12 @@ func (k Keeper) HandleRelay(ctx sdk.Ctx, relay pc.Relay) (*pc.RelayResponse, sdk
 		}
 		return nil, err
 	}
-	// store the proof before execution, because the proof corresponds to the previous relay
-	relay.Proof.Store(maxPossibleRelays, servicerNode.EvidenceStore)
+	// move this to a worker that will insert this proof in a series style to avoid memory consumption and relay proof race conditions
+	// https://github.com/pokt-network/pocket-core/issues/1457
+	pc.GlobalEvidenceWorker.Submit(func() {
+		// store the proof before execution, because the proof corresponds to the previous relay
+		relay.Proof.Store(maxPossibleRelays, servicerNode.EvidenceStore)
+	})
 	// attempt to execute
 	respPayload, err := relay.Execute(hostedBlockchains, &servicerNodeAddr)
 	if err != nil {

x/pocketcore/keeper/service_test.go

@@ -108,6 +108,10 @@ func testRelayAt(
 	assert.Nil(t, er)
 	validRelay.Proof.Signature = hex.EncodeToString(clientSig)
 
+	httpClient := types.GetChainsClient()
+	defer gock.Off() // Flush pending mocks after test execution
+	defer gock.RestoreClient(httpClient)
+	gock.InterceptClient(httpClient)
 	gock.New("https://www.google.com:443").
 		Post("/").
 		Reply(200).

x/pocketcore/types/config.go

@@ -3,6 +3,7 @@ package types
 import (
 	"encoding/hex"
 	"fmt"
+	"github.com/alitto/pond"
 	"github.com/pokt-network/pocket-core/crypto"
 	"github.com/pokt-network/pocket-core/types"
 	"github.com/tendermint/tendermint/config"
@@ -20,13 +21,16 @@ var (
 	globalRPCTimeout       time.Duration
 	GlobalPocketConfig     types.PocketConfig
 	GlobalTenderMintConfig config.Config
+	GlobalEvidenceWorker   *pond.WorkerPool
 )
 
 func InitConfig(chains *HostedBlockchains, logger log.Logger, c types.Config) {
 	ConfigOnce.Do(func() {
 		InitGlobalServiceMetric(chains, logger, c.PocketConfig.PrometheusAddr, c.PocketConfig.PrometheusMaxOpenfiles)
 	})
+	InitHttpClient(c.PocketConfig.RPCMaxIdleConns, c.PocketConfig.RPCMaxConnsPerHost, c.PocketConfig.RPCMaxIdleConnsPerHost)
 	InitPocketNodeCaches(c, logger)
+	InitEvidenceWorker(c, logger)
 	GlobalPocketConfig = c.PocketConfig
 	GlobalTenderMintConfig = c.TendermintConfig
 	if GlobalPocketConfig.LeanPocket {
@@ -37,6 +41,18 @@ func InitConfig(chains *HostedBlockchains, logger log.Logger, c types.Config) {
 	SetRPCTimeout(c.PocketConfig.RPCTimeout)
 }
 
+func InitEvidenceWorker(_ types.Config, logger log.Logger) {
+	panicHandler := func(p interface{}) {
+		logger.Error(fmt.Sprintf("evidence storage task panicked: %v", p))
+	}
+	GlobalEvidenceWorker = pond.New(
+		1, 0,
+		pond.IdleTimeout(100),
+		pond.PanicHandler(panicHandler),
+		pond.Strategy(pond.Balanced()),
+	)
+}
+
 func ConvertEvidenceToProto(config types.Config) error {
 	// we have to add a random pocket node so that way lean pokt can still support getting the global evidence cache
 	node := AddPocketNode(crypto.GenerateEd25519PrivKey().GenPrivateKey(), log.NewNopLogger())
@@ -67,6 +83,13 @@ func ConvertEvidenceToProto(config types.Config) error {
 	return nil
 }
 
+func StopEvidenceWorker() {
+	if !GlobalEvidenceWorker.Stopped() {
+		GlobalEvidenceWorker.StopAndWait()
+	}
+	GlobalEvidenceWorker = nil
+}
+
 func FlushSessionCache() {
 	for _, k := range GlobalPocketNodes {
 		if k.SessionStore != nil {

x/pocketcore/types/service.go

@@ -18,13 +18,47 @@ import (
 
 const DEFAULTHTTPMETHOD = "POST"
 
+var (
+	chainHttpClient *http.Client
+)
+
 // "Relay" - A read / write API request to a hosted (non-native) external blockchain
 type Relay struct {
 	Payload Payload    `json:"payload"` // the data payload of the request
 	Meta    RelayMeta  `json:"meta"`    // metadata for the relay request
 	Proof   RelayProof `json:"proof"`   // the authentication scheme needed for work
 }
 
+func GetChainsClient() *http.Client {
+	if chainHttpClient == nil {
+		InitHttpClient(1000, 1000, 1000)
+	}
+
+	return chainHttpClient
+}
+
+func InitHttpClient(maxIdleConns, maxConnsPerHost, maxIdleConnsPerHost int) {
+	var chainsTransport *http.Transport
+
+	t, ok := http.DefaultTransport.(*http.Transport)
+	if ok {
+		chainsTransport = t.Clone()
+		// this params may could be handled by config.json, but how much people know about this?
+		// tbd: figure out the right values to this, rn the priority is stop recreating new http client and connections.
+		chainsTransport.MaxIdleConns = maxIdleConns
+		chainsTransport.MaxConnsPerHost = maxConnsPerHost
+		chainsTransport.MaxIdleConnsPerHost = maxIdleConnsPerHost
+	} // if not ok, probably is because is *gock.Transport - test only
+
+	chainHttpClient = &http.Client{
+		Timeout: globalRPCTimeout * time.Second,
+	}
+
+	if chainsTransport != nil {
+		chainHttpClient.Transport = chainsTransport
+	}
+}
+
 // "Validate" - Checks the validity of a Relay Request using store data
 func (r *Relay) Validate(
 	ctx sdk.Ctx,
@@ -349,7 +383,7 @@ func executeHTTPRequest(payload, url, userAgent string, basicAuth BasicAuth, met
 		}
 	}
 	// execute the request
-	resp, err := (&http.Client{Timeout: globalRPCTimeout * time.Millisecond}).Do(req)
+	resp, err := GetChainsClient().Do(req)
 	if err != nil {
 		return "", err
 	}

x/pocketcore/types/service_test.go

@@ -169,8 +169,10 @@ func TestRelay_Execute(t *testing.T) {
 		},
 	}
 	validRelay.Proof.RequestHash = validRelay.RequestHashString()
+	httpClient := GetChainsClient()
 	defer gock.Off() // Flush pending mocks after test execution
-
+	defer gock.RestoreClient(httpClient)
+	gock.InterceptClient(httpClient)
 	gock.New("https://server.com").
 		Post("/relay").
 		Reply(200).
@@ -182,6 +184,7 @@ func TestRelay_Execute(t *testing.T) {
 			URL: "https://server.com/relay/",
 		}},
 	}
+
 	response, err := validRelay.Execute(&hb, &nodeAddr)
 	assert.True(t, err == nil)
 	assert.Equal(t, response, "bar")