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-rw-r--r--swarm/shed/db.go205
-rw-r--r--swarm/shed/db_test.go6
-rw-r--r--swarm/shed/example_store_test.go2
3 files changed, 206 insertions, 7 deletions
diff --git a/swarm/shed/db.go b/swarm/shed/db.go
index e128b8cbc..7377e12d2 100644
--- a/swarm/shed/db.go
+++ b/swarm/shed/db.go
@@ -23,14 +23,23 @@
package shed
import (
+ "errors"
+ "fmt"
+ "strconv"
+ "strings"
+ "time"
+
"github.com/ethereum/go-ethereum/metrics"
+ "github.com/ethereum/go-ethereum/swarm/log"
"github.com/syndtr/goleveldb/leveldb"
"github.com/syndtr/goleveldb/leveldb/iterator"
"github.com/syndtr/goleveldb/leveldb/opt"
)
-// The limit for LevelDB OpenFilesCacheCapacity.
-const openFileLimit = 128
+const (
+ openFileLimit = 128 // The limit for LevelDB OpenFilesCacheCapacity.
+ writePauseWarningThrottler = 1 * time.Minute
+)
// DB provides abstractions over LevelDB in order to
// implement complex structures using fields and ordered indexes.
@@ -38,11 +47,22 @@ const openFileLimit = 128
// information about naming and types.
type DB struct {
ldb *leveldb.DB
+
+ compTimeMeter metrics.Meter // Meter for measuring the total time spent in database compaction
+ compReadMeter metrics.Meter // Meter for measuring the data read during compaction
+ compWriteMeter metrics.Meter // Meter for measuring the data written during compaction
+ writeDelayNMeter metrics.Meter // Meter for measuring the write delay number due to database compaction
+ writeDelayMeter metrics.Meter // Meter for measuring the write delay duration due to database compaction
+ diskReadMeter metrics.Meter // Meter for measuring the effective amount of data read
+ diskWriteMeter metrics.Meter // Meter for measuring the effective amount of data written
+
+ quitChan chan chan error // Quit channel to stop the metrics collection before closing the database
}
// NewDB constructs a new DB and validates the schema
// if it exists in database on the given path.
-func NewDB(path string) (db *DB, err error) {
+// metricsPrefix is used for metrics collection for the given DB.
+func NewDB(path string, metricsPrefix string) (db *DB, err error) {
ldb, err := leveldb.OpenFile(path, &opt.Options{
OpenFilesCacheCapacity: openFileLimit,
})
@@ -66,6 +86,15 @@ func NewDB(path string) (db *DB, err error) {
return nil, err
}
}
+
+ // Configure meters for DB
+ db.configure(metricsPrefix)
+
+ // Create a quit channel for the periodic metrics collector and run it
+ db.quitChan = make(chan chan error)
+
+ go db.meter(10 * time.Second)
+
return db, nil
}
@@ -126,5 +155,175 @@ func (db *DB) WriteBatch(batch *leveldb.Batch) (err error) {
// Close closes LevelDB database.
func (db *DB) Close() (err error) {
+ close(db.quitChan)
return db.ldb.Close()
}
+
+// Configure configures the database metrics collectors
+func (db *DB) configure(prefix string) {
+ // Initialize all the metrics collector at the requested prefix
+ db.compTimeMeter = metrics.NewRegisteredMeter(prefix+"compact/time", nil)
+ db.compReadMeter = metrics.NewRegisteredMeter(prefix+"compact/input", nil)
+ db.compWriteMeter = metrics.NewRegisteredMeter(prefix+"compact/output", nil)
+ db.diskReadMeter = metrics.NewRegisteredMeter(prefix+"disk/read", nil)
+ db.diskWriteMeter = metrics.NewRegisteredMeter(prefix+"disk/write", nil)
+ db.writeDelayMeter = metrics.NewRegisteredMeter(prefix+"compact/writedelay/duration", nil)
+ db.writeDelayNMeter = metrics.NewRegisteredMeter(prefix+"compact/writedelay/counter", nil)
+}
+
+func (db *DB) meter(refresh time.Duration) {
+ // Create the counters to store current and previous compaction values
+ compactions := make([][]float64, 2)
+ for i := 0; i < 2; i++ {
+ compactions[i] = make([]float64, 3)
+ }
+ // Create storage for iostats.
+ var iostats [2]float64
+
+ // Create storage and warning log tracer for write delay.
+ var (
+ delaystats [2]int64
+ lastWritePaused time.Time
+ )
+
+ var (
+ errc chan error
+ merr error
+ )
+
+ // Iterate ad infinitum and collect the stats
+ for i := 1; errc == nil && merr == nil; i++ {
+ // Retrieve the database stats
+ stats, err := db.ldb.GetProperty("leveldb.stats")
+ if err != nil {
+ log.Error("Failed to read database stats", "err", err)
+ merr = err
+ continue
+ }
+ // Find the compaction table, skip the header
+ lines := strings.Split(stats, "\n")
+ for len(lines) > 0 && strings.TrimSpace(lines[0]) != "Compactions" {
+ lines = lines[1:]
+ }
+ if len(lines) <= 3 {
+ log.Error("Compaction table not found")
+ merr = errors.New("compaction table not found")
+ continue
+ }
+ lines = lines[3:]
+
+ // Iterate over all the table rows, and accumulate the entries
+ for j := 0; j < len(compactions[i%2]); j++ {
+ compactions[i%2][j] = 0
+ }
+ for _, line := range lines {
+ parts := strings.Split(line, "|")
+ if len(parts) != 6 {
+ break
+ }
+ for idx, counter := range parts[3:] {
+ value, err := strconv.ParseFloat(strings.TrimSpace(counter), 64)
+ if err != nil {
+ log.Error("Compaction entry parsing failed", "err", err)
+ merr = err
+ continue
+ }
+ compactions[i%2][idx] += value
+ }
+ }
+ // Update all the requested meters
+ if db.compTimeMeter != nil {
+ db.compTimeMeter.Mark(int64((compactions[i%2][0] - compactions[(i-1)%2][0]) * 1000 * 1000 * 1000))
+ }
+ if db.compReadMeter != nil {
+ db.compReadMeter.Mark(int64((compactions[i%2][1] - compactions[(i-1)%2][1]) * 1024 * 1024))
+ }
+ if db.compWriteMeter != nil {
+ db.compWriteMeter.Mark(int64((compactions[i%2][2] - compactions[(i-1)%2][2]) * 1024 * 1024))
+ }
+
+ // Retrieve the write delay statistic
+ writedelay, err := db.ldb.GetProperty("leveldb.writedelay")
+ if err != nil {
+ log.Error("Failed to read database write delay statistic", "err", err)
+ merr = err
+ continue
+ }
+ var (
+ delayN int64
+ delayDuration string
+ duration time.Duration
+ paused bool
+ )
+ if n, err := fmt.Sscanf(writedelay, "DelayN:%d Delay:%s Paused:%t", &delayN, &delayDuration, &paused); n != 3 || err != nil {
+ log.Error("Write delay statistic not found")
+ merr = err
+ continue
+ }
+ duration, err = time.ParseDuration(delayDuration)
+ if err != nil {
+ log.Error("Failed to parse delay duration", "err", err)
+ merr = err
+ continue
+ }
+ if db.writeDelayNMeter != nil {
+ db.writeDelayNMeter.Mark(delayN - delaystats[0])
+ }
+ if db.writeDelayMeter != nil {
+ db.writeDelayMeter.Mark(duration.Nanoseconds() - delaystats[1])
+ }
+ // If a warning that db is performing compaction has been displayed, any subsequent
+ // warnings will be withheld for one minute not to overwhelm the user.
+ if paused && delayN-delaystats[0] == 0 && duration.Nanoseconds()-delaystats[1] == 0 &&
+ time.Now().After(lastWritePaused.Add(writePauseWarningThrottler)) {
+ log.Warn("Database compacting, degraded performance")
+ lastWritePaused = time.Now()
+ }
+ delaystats[0], delaystats[1] = delayN, duration.Nanoseconds()
+
+ // Retrieve the database iostats.
+ ioStats, err := db.ldb.GetProperty("leveldb.iostats")
+ if err != nil {
+ log.Error("Failed to read database iostats", "err", err)
+ merr = err
+ continue
+ }
+ var nRead, nWrite float64
+ parts := strings.Split(ioStats, " ")
+ if len(parts) < 2 {
+ log.Error("Bad syntax of ioStats", "ioStats", ioStats)
+ merr = fmt.Errorf("bad syntax of ioStats %s", ioStats)
+ continue
+ }
+ if n, err := fmt.Sscanf(parts[0], "Read(MB):%f", &nRead); n != 1 || err != nil {
+ log.Error("Bad syntax of read entry", "entry", parts[0])
+ merr = err
+ continue
+ }
+ if n, err := fmt.Sscanf(parts[1], "Write(MB):%f", &nWrite); n != 1 || err != nil {
+ log.Error("Bad syntax of write entry", "entry", parts[1])
+ merr = err
+ continue
+ }
+ if db.diskReadMeter != nil {
+ db.diskReadMeter.Mark(int64((nRead - iostats[0]) * 1024 * 1024))
+ }
+ if db.diskWriteMeter != nil {
+ db.diskWriteMeter.Mark(int64((nWrite - iostats[1]) * 1024 * 1024))
+ }
+ iostats[0], iostats[1] = nRead, nWrite
+
+ // Sleep a bit, then repeat the stats collection
+ select {
+ case errc = <-db.quitChan:
+ // Quit requesting, stop hammering the database
+ case <-time.After(refresh):
+ // Timeout, gather a new set of stats
+ }
+ }
+
+ if errc == nil {
+ errc = <-db.quitChan
+ }
+ errc <- merr
+}
diff --git a/swarm/shed/db_test.go b/swarm/shed/db_test.go
index 45325beeb..65fdac4a6 100644
--- a/swarm/shed/db_test.go
+++ b/swarm/shed/db_test.go
@@ -55,7 +55,7 @@ func TestDB_persistence(t *testing.T) {
}
defer os.RemoveAll(dir)
- db, err := NewDB(dir)
+ db, err := NewDB(dir, "")
if err != nil {
t.Fatal(err)
}
@@ -73,7 +73,7 @@ func TestDB_persistence(t *testing.T) {
t.Fatal(err)
}
- db2, err := NewDB(dir)
+ db2, err := NewDB(dir, "")
if err != nil {
t.Fatal(err)
}
@@ -101,7 +101,7 @@ func newTestDB(t *testing.T) (db *DB, cleanupFunc func()) {
t.Fatal(err)
}
cleanupFunc = func() { os.RemoveAll(dir) }
- db, err = NewDB(dir)
+ db, err = NewDB(dir, "")
if err != nil {
cleanupFunc()
t.Fatal(err)
diff --git a/swarm/shed/example_store_test.go b/swarm/shed/example_store_test.go
index 2ed0be141..908a1e446 100644
--- a/swarm/shed/example_store_test.go
+++ b/swarm/shed/example_store_test.go
@@ -52,7 +52,7 @@ type Store struct {
// and possible conflicts with schema from existing database is checked
// automatically.
func New(path string) (s *Store, err error) {
- db, err := shed.NewDB(path)
+ db, err := shed.NewDB(path, "")
if err != nil {
return nil, err
}