4 files changed, 146 insertions, 2 deletions
diff --git a/cmd/utils/fdlimit_test.go b/cmd/utils/fdlimit_test.go
new file mode 100644
index 000000000..0a950a6c9
--- /dev/null
+++ b/cmd/utils/fdlimit_test.go
@@ -0,0 +1,35 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package utils
+
+import "testing"
+
+// TestFileDescriptorLimits simply tests whether the file descriptor allowance
+// per this process can be retrieved.
+func TestFileDescriptorLimits(t *testing.T) {
+	target := 4096
+
+	if limit, err := getFdLimit(); err != nil || limit <= 0 {
+		t.Fatalf("failed to retrieve file descriptor limit (%d): %v", limit, err)
+	}
+	if err := raiseFdLimit(uint64(target)); err != nil {
+		t.Fatalf("failed to raise file allowance")
+	}
+	if limit, err := getFdLimit(); err != nil || limit < target {
+		t.Fatalf("failed to retrieve raised descriptor limit (have %v, want %v): %v", limit, target, err)
+	}
+}
diff --git a/cmd/utils/fdlimit_unix.go b/cmd/utils/fdlimit_unix.go
new file mode 100644
index 000000000..2a6dffc8f
--- /dev/null
+++ b/cmd/utils/fdlimit_unix.go
@@ -0,0 +1,50 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+// +build linux darwin
+
+package utils
+
+import "syscall"
+
+// raiseFdLimit tries to maximize the file descriptor allowance of this process
+// to the maximum hard-limit allowed by the OS.
+func raiseFdLimit(max uint64) error {
+	// Get the current limit
+	var limit syscall.Rlimit
+	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
+		return err
+	}
+	// Try to update the limit to the max allowance
+	limit.Cur = limit.Max
+	if limit.Cur > max {
+		limit.Cur = max
+	}
+	if err := syscall.Setrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
+		return err
+	}
+	return nil
+}
+
+// getFdLimit retrieves the number of file descriptors allowed to be opened by this
+// process.
+func getFdLimit() (int, error) {
+	var limit syscall.Rlimit
+	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &limit); err != nil {
+		return 0, err
+	}
+	return int(limit.Cur), nil
+}
diff --git a/cmd/utils/fdlimit_windows.go b/cmd/utils/fdlimit_windows.go
new file mode 100644
index 000000000..53aad3d7a
--- /dev/null
+++ b/cmd/utils/fdlimit_windows.go
@@ -0,0 +1,41 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package utils
+
+import "errors"
+
+// raiseFdLimit tries to maximize the file descriptor allowance of this process
+// to the maximum hard-limit allowed by the OS.
+func raiseFdLimit(max uint64) error {
+	// This method is NOP by design:
+	//  * Linux/Darwin counterparts need to manually increase per process limits
+	//  * On Windows Go uses the CreateFile API, which is limited to 16K files, non
+	//    changeable from within a running process
+	// This way we can always "request" raising the limits, which will either have
+	// or not have effect based on the platform we're running on.
+	if max > 16384 {
+		return errors.New("file descriptor limit (16384) reached")
+	}
+	return nil
+}
+
+// getFdLimit retrieves the number of file descriptors allowed to be opened by this
+// process.
+func getFdLimit() (int, error) {
+	// Please see raiseFdLimit for the reason why we use hard coded 16K as the limit
+	return 16384, nil
+}
diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index 3efb65e42..69fb0b9db 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -143,7 +143,7 @@ var (
 	CacheFlag = cli.IntFlag{
 		Name:  "cache",
 		Usage: "Megabytes of memory allocated to internal caching (min 16MB / database forced)",
-		Value: 0,
+		Value: 128,
 	}
 	BlockchainVersionFlag = cli.IntFlag{
 		Name:  "blockchainversion",
@@ -527,6 +527,22 @@ func MakeGenesisBlock(ctx *cli.Context) string {
 	return string(data)
 }
 
+// MakeDatabaseHandles raises out the number of allowed file handles per process
+// for Geth and returns half of the allowance to assign to the database.
+func MakeDatabaseHandles() int {
+	if err := raiseFdLimit(2048); err != nil {
+		Fatalf("Failed to raise file descriptor allowance: %v", err)
+	}
+	limit, err := getFdLimit()
+	if err != nil {
+		Fatalf("Failed to retrieve file descriptor allowance: %v", err)
+	}
+	if limit > 2048 { // cap database file descriptors even if more is available
+		limit = 2048
+	}
+	return limit / 2 // Leave half for networking and other stuff
+}
+
 // MakeAccountManager creates an account manager from set command line flags.
 func MakeAccountManager(ctx *cli.Context) *accounts.Manager {
 	// Create the keystore crypto primitive, light if requested
@@ -649,6 +665,7 @@ func MakeSystemNode(name, version string, extra []byte, ctx *cli.Context) *node.
 		FastSync:                ctx.GlobalBool(FastSyncFlag.Name),
 		BlockChainVersion:       ctx.GlobalInt(BlockchainVersionFlag.Name),
 		DatabaseCache:           ctx.GlobalInt(CacheFlag.Name),
+		DatabaseHandles:         MakeDatabaseHandles(),
 		NetworkId:               ctx.GlobalInt(NetworkIdFlag.Name),
 		AccountManager:          accman,
 		Etherbase:               MakeEtherbase(accman, ctx),
@@ -763,9 +780,10 @@ func SetupVM(ctx *cli.Context) {
 func MakeChain(ctx *cli.Context) (chain *core.BlockChain, chainDb ethdb.Database) {
 	datadir := MustMakeDataDir(ctx)
 	cache := ctx.GlobalInt(CacheFlag.Name)
+	handles := MakeDatabaseHandles()
 
 	var err error
-	if chainDb, err = ethdb.NewLDBDatabase(filepath.Join(datadir, "chaindata"), cache); err != nil {
+	if chainDb, err = ethdb.NewLDBDatabase(filepath.Join(datadir, "chaindata"), cache, handles); err != nil {
 		Fatalf("Could not open database: %v", err)
 	}
 	if ctx.GlobalBool(OlympicFlag.Name) {