swarm: initial instrumentation (#15969)

* swarm: initial instrumentation with go-metrics

* swarm: initialise metrics collection and add ResettingTimer to HTTP requests

* swarm: update metrics flags names. remove redundant Timer.

* swarm: rename method for periodically updating gauges

* swarm: finalise metrics after feedback

* swarm/network: always init kad metrics containers

* swarm/network: off-by-one index in metrics containers

* swarm, metrics: resolved conflicts

4 files changed, 53 insertions, 0 deletions

diff --git a/swarm/storage/chunker.go b/swarm/storage/chunker.go
index 98cd6e75e..2b397f801 100644
--- a/swarm/storage/chunker.go
+++ b/swarm/storage/chunker.go
@@ -23,6 +23,8 @@ import (
 	"io"
 	"sync"
 	"time"
+
+	"github.com/ethereum/go-ethereum/metrics"
 )
 
 /*
@@ -63,6 +65,11 @@ var (
 	errOperationTimedOut    = errors.New("operation timed out")
 )
 
+//metrics variables
+var (
+	newChunkCounter = metrics.NewRegisteredCounter("storage.chunks.new", nil)
+)
+
 type TreeChunker struct {
 	branches int64
 	hashFunc SwarmHasher
@@ -298,6 +305,13 @@ func (self *TreeChunker) hashChunk(hasher SwarmHash, job *hashJob, chunkC chan *
 	job.parentWg.Done()
 
 	if chunkC != nil {
+		//NOTE: this increases the chunk count even if the local node already has this chunk;
+		//on file upload the node will increase this counter even if the same file has already been uploaded
+		//So it should be evaluated whether it is worth keeping this counter
+		//and/or actually better track when the chunk is Put to the local database
+		//(which may question the need for disambiguation when a completely new chunk has been created
+		//and/or a chunk is being put to the local DB; for chunk tracking it may be worth distinguishing
+		newChunkCounter.Inc(1)
 		chunkC <- newChunk
 	}
 }
diff --git a/swarm/storage/dbstore.go b/swarm/storage/dbstore.go
index 46a5c16cc..421bb061d 100644
--- a/swarm/storage/dbstore.go
+++ b/swarm/storage/dbstore.go
@@ -33,11 +33,18 @@ import (
 	"sync"
 
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/syndtr/goleveldb/leveldb"
 	"github.com/syndtr/goleveldb/leveldb/iterator"
 )
 
+//metrics variables
+var (
+	gcCounter            = metrics.NewRegisteredCounter("storage.db.dbstore.gc.count", nil)
+	dbStoreDeleteCounter = metrics.NewRegisteredCounter("storage.db.dbstore.rm.count", nil)
+)
+
 const (
 	defaultDbCapacity = 5000000
 	defaultRadius     = 0 // not yet used
@@ -255,6 +262,7 @@ func (s *DbStore) collectGarbage(ratio float32) {
 	// actual gc
 	for i := 0; i < gcnt; i++ {
 		if s.gcArray[i].value <= cutval {
+			gcCounter.Inc(1)
 			s.delete(s.gcArray[i].idx, s.gcArray[i].idxKey)
 		}
 	}
@@ -383,6 +391,7 @@ func (s *DbStore) delete(idx uint64, idxKey []byte) {
 	batch := new(leveldb.Batch)
 	batch.Delete(idxKey)
 	batch.Delete(getDataKey(idx))
+	dbStoreDeleteCounter.Inc(1)
 	s.entryCnt--
 	batch.Put(keyEntryCnt, U64ToBytes(s.entryCnt))
 	s.db.Write(batch)
diff --git a/swarm/storage/localstore.go b/swarm/storage/localstore.go
index b442e6cc5..ece0c8615 100644
--- a/swarm/storage/localstore.go
+++ b/swarm/storage/localstore.go
@@ -18,6 +18,13 @@ package storage
 
 import (
 	"encoding/binary"
+
+	"github.com/ethereum/go-ethereum/metrics"
+)
+
+//metrics variables
+var (
+	dbStorePutCounter = metrics.NewRegisteredCounter("storage.db.dbstore.put.count", nil)
 )
 
 // LocalStore is a combination of inmemory db over a disk persisted db
@@ -39,6 +46,14 @@ func NewLocalStore(hash SwarmHasher, params *StoreParams) (*LocalStore, error) {
 	}, nil
 }
 
+func (self *LocalStore) CacheCounter() uint64 {
+	return uint64(self.memStore.(*MemStore).Counter())
+}
+
+func (self *LocalStore) DbCounter() uint64 {
+	return self.DbStore.(*DbStore).Counter()
+}
+
 // LocalStore is itself a chunk store
 // unsafe, in that the data is not integrity checked
 func (self *LocalStore) Put(chunk *Chunk) {
@@ -48,6 +63,7 @@ func (self *LocalStore) Put(chunk *Chunk) {
 		chunk.wg.Add(1)
 	}
 	go func() {
+		dbStorePutCounter.Inc(1)
 		self.DbStore.Put(chunk)
 		if chunk.wg != nil {
 			chunk.wg.Done()
diff --git a/swarm/storage/memstore.go b/swarm/storage/memstore.go
index 3cb25ac62..d6be54220 100644
--- a/swarm/storage/memstore.go
+++ b/swarm/storage/memstore.go
@@ -23,6 +23,13 @@ import (
 	"sync"
 
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/metrics"
+)
+
+//metrics variables
+var (
+	memstorePutCounter    = metrics.NewRegisteredCounter("storage.db.memstore.put.count", nil)
+	memstoreRemoveCounter = metrics.NewRegisteredCounter("storage.db.memstore.rm.count", nil)
 )
 
 const (
@@ -130,6 +137,10 @@ func (s *MemStore) setCapacity(c uint) {
 	s.capacity = c
 }
 
+func (s *MemStore) Counter() uint {
+	return s.entryCnt
+}
+
 // entry (not its copy) is going to be in MemStore
 func (s *MemStore) Put(entry *Chunk) {
 	if s.capacity == 0 {
@@ -145,6 +156,8 @@ func (s *MemStore) Put(entry *Chunk) {
 
 	s.accessCnt++
 
+	memstorePutCounter.Inc(1)
+
 	node := s.memtree
 	bitpos := uint(0)
 	for node.entry == nil {
@@ -289,6 +302,7 @@ func (s *MemStore) removeOldest() {
 	}
 
 	if node.entry.SData != nil {
+		memstoreRemoveCounter.Inc(1)
 		node.entry = nil
 		s.entryCnt--
 	}