[lbry] ffldb: increase open file limit and flush more often

database/ffldb/blockio.go

@@ -37,7 +37,7 @@ const (
 	// maxOpenFiles is the max number of open files to maintain in the
 	// open blocks cache.  Note that this does not include the current
 	// write file, so there will typically be one more than this value open.
-	maxOpenFiles = 25
+	maxOpenFiles = 40
 
 	// maxBlockFileSize is the maximum size for each file used to store
 	// blocks.

database/ffldb/db.go

@@ -2001,10 +2001,11 @@ func openDB(dbPath string, network wire.BitcoinNet, create bool) (database.DB, e
 
 	// Open the metadata database (will create it if needed).
 	opts := opt.Options{
-		ErrorIfExist: create,
-		Strict:       opt.DefaultStrict,
-		Compression:  opt.NoCompression,
-		Filter:       filter.NewBloomFilter(10),
+		ErrorIfExist:           create,
+		Strict:                 opt.DefaultStrict,
+		Compression:            opt.NoCompression,
+		Filter:                 filter.NewBloomFilter(10),
+		OpenFilesCacheCapacity: 2000,
 	}
 	ldb, err := leveldb.OpenFile(metadataDbPath, &opts)
 	if err != nil {

database/ffldb/dbcache.go

@@ -23,7 +23,7 @@ const (
 	// defaultFlushSecs is the default number of seconds to use as a
 	// threshold in between database cache flushes when the cache size has
 	// not been exceeded.
-	defaultFlushSecs = 300 // 5 minutes
+	defaultFlushSecs = 120 // 2 minutes
 
 	// ldbBatchHeaderSize is the size of a leveldb batch header which
 	// includes the sequence header and record counter.
@@ -499,10 +499,12 @@ func (c *dbCache) flush() error {
 	// Since the cached keys to be added and removed use an immutable treap,
 	// a snapshot is simply obtaining the root of the tree under the lock
 	// which is used to atomically swap the root.
-	c.cacheLock.RLock()
+	c.cacheLock.Lock()
 	cachedKeys := c.cachedKeys
 	cachedRemove := c.cachedRemove
-	c.cacheLock.RUnlock()
+	c.cachedKeys = treap.NewImmutable()
+	c.cachedRemove = treap.NewImmutable()
+	c.cacheLock.Unlock()
 
 	// Nothing to do if there is no data to flush.
 	if cachedKeys.Len() == 0 && cachedRemove.Len() == 0 {
@@ -514,12 +516,6 @@ func (c *dbCache) flush() error {
 		return err
 	}
 
-	// Clear the cache since it has been flushed.
-	c.cacheLock.Lock()
-	c.cachedKeys = treap.NewImmutable()
-	c.cachedRemove = treap.NewImmutable()
-	c.cacheLock.Unlock()
-
 	return nil
 }