Add Zones system table.

Work towards: #2090

Additional tweaks:
* fix all tests that depend on the number of system databases/tables
  to use dynamic counts.
* rework the SystemDBSPan loading a bit. change checksum to sha1 and
  include keys.

kv/dist_sender_server_test.go

@@ -28,6 +28,7 @@ import (
 	"github.com/cockroachdb/cockroach/kv"
 	"github.com/cockroachdb/cockroach/proto"
 	"github.com/cockroachdb/cockroach/server"
+	"github.com/cockroachdb/cockroach/sql"
 	"github.com/cockroachdb/cockroach/storage/engine"
 	"github.com/cockroachdb/cockroach/testutils"
 	"github.com/cockroachdb/cockroach/util/hlc"
@@ -255,11 +256,12 @@ func TestSingleRangeReverseScan(t *testing.T) {
 		t.Errorf("expected 2 rows; got %d", l)
 	}
 	// Case 3: Test proto.KeyMax
-	// TODO(marc): this depends on the sql system objects.
+	// This span covers the system DB keys.
+	wanted := 1 + len(sql.GetInitialSystemValues())
 	if rows, err := db.ReverseScan("g", proto.KeyMax, 0); err != nil {
 		t.Fatalf("unexpected error on ReverseScan: %s", err)
-	} else if l := len(rows); l != 10 {
-		t.Errorf("expected 10 rows; got %d", l)
+	} else if l := len(rows); l != wanted {
+		t.Errorf("expected %d rows; got %d", wanted, l)
 	}
 	// Case 4: Test keys.SystemMax
 	if rows, err := db.ReverseScan(keys.SystemMax, "b", 0); err != nil {

server/node_test.go

@@ -35,6 +35,7 @@ import (
 	"github.com/cockroachdb/cockroach/proto"
 	"github.com/cockroachdb/cockroach/rpc"
 	"github.com/cockroachdb/cockroach/server/status"
+	"github.com/cockroachdb/cockroach/sql"
 	"github.com/cockroachdb/cockroach/storage"
 	"github.com/cockroachdb/cockroach/storage/engine"
 	"github.com/cockroachdb/cockroach/util"
@@ -114,31 +115,28 @@ func TestBootstrapCluster(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	var keys []proto.Key
+	var foundKeys proto.KeySlice
 	for _, kv := range rows {
-		keys = append(keys, kv.Key)
+		foundKeys = append(foundKeys, kv.Key)
 	}
-	// TODO(marc): this depends on the sql system objects.
-	var expectedKeys = []proto.Key{
+	var expectedKeys = proto.KeySlice{
 		proto.MakeKey(proto.Key("\x00\x00meta1"), proto.KeyMax),
 		proto.MakeKey(proto.Key("\x00\x00meta2"), proto.KeyMax),
-		proto.Key("\x00desc-idgen"),
 		proto.Key("\x00node-idgen"),
 		proto.Key("\x00range-tree-root"),
 		proto.Key("\x00store-idgen"),
 		proto.Key("\x00zone"),
-		proto.Key("\xff\n\x02\n\x01\tsystem\x00\x01\n\x03"),
-		proto.Key("\xff\n\x02\n\x01\n\x01descriptor\x00\x01\n\x03"),
-		proto.Key("\xff\n\x02\n\x01\n\x01namespace\x00\x01\n\x03"),
-		proto.Key("\xff\n\x02\n\x01\n\x01users\x00\x01\n\x03"),
-		proto.Key("\xff\n\x03\n\x01\n\x01\n\x02"),
-		proto.Key("\xff\n\x03\n\x01\n\x02\n\x02"),
-		proto.Key("\xff\n\x03\n\x01\n\x03\n\x02"),
-		proto.Key("\xff\n\x03\n\x01\n\x04\n\x02"),
-	}
-	if !reflect.DeepEqual(keys, expectedKeys) {
+	}
+	// Add the initial keys for sql.
+	for _, kv := range sql.GetInitialSystemValues() {
+		expectedKeys = append(expectedKeys, kv.Key)
+	}
+	// Resort the list. The sql values are not sorted.
+	sort.Sort(expectedKeys)
+
+	if !reflect.DeepEqual(foundKeys, expectedKeys) {
 		t.Errorf("expected keys mismatch:\n%s\n  -- vs. -- \n\n%s",
-			formatKeys(keys), formatKeys(expectedKeys))
+			formatKeys(foundKeys), formatKeys(expectedKeys))
 	}
 
 	// TODO(spencer): check values.

sql/create_test.go

@@ -72,8 +72,7 @@ func TestDatabaseDescriptor(t *testing.T) {
 	if kvs, err := kvDB.Scan(start, start.PrefixEnd(), 0); err != nil {
 		t.Fatal(err)
 	} else {
-		// TODO(marc): this is the number of system tables + 1.
-		if a, e := len(kvs), 4; a != e {
+		if a, e := len(kvs), sql.NumUsedSystemIDs; a != e {
 			t.Fatalf("expected %d keys to have been written, found %d keys", e, a)
 		}
 	}

sql/system.go

@@ -40,9 +40,9 @@ const (
 	namespaceTableID  ID = 2
 	descriptorTableID ID = 3
 	usersTableID      ID = 4
+	zonesTableID      ID = 5
 
 	// sql CREATE commands and full schema for each system table.
-	// TODO(marc): wouldn't it be better to use a pre-parsed version?
 	namespaceTableSchema = `
 CREATE TABLE system.namespace (
   parentID INT,
@@ -62,6 +62,13 @@ CREATE TABLE system.users (
   username       CHAR PRIMARY KEY,
   hashedPassword BLOB
 );`
+
+	// Zone settings per DB/Table.
+	zonesTableSchema = `
+CREATE TABLE system.zones (
+  id     INT PRIMARY KEY,
+  config BLOB
+);`
 )
 
 var (
@@ -83,6 +90,9 @@ var (
 	// UsersTable is the descriptor for the users table.
 	UsersTable = createSystemTable(usersTableID, usersTableSchema)
 
+	// ZonesTable is the descriptor for the zones table.
+	ZonesTable = createSystemTable(zonesTableID, zonesTableSchema)
+
 	// SystemAllowedPrivileges describes the privileges allowed for each
 	// system object. No user may have more than those privileges, and
 	// the root user must have exactly those privileges.
@@ -92,7 +102,14 @@ var (
 		namespaceTableID:  privilege.ReadData,
 		descriptorTableID: privilege.ReadData,
 		usersTableID:      privilege.ReadWriteData,
+		zonesTableID:      privilege.ReadWriteData,
 	}
+
+	// NumUsedSystemIDs is only used in tests that need to know the
+	// number of system objects created at initialization.
+	// It gets automatically set to "number of created system tables"
+	// + 1 (for system database).
+	NumUsedSystemIDs = 1
 )
 
 func createSystemTable(id ID, cmd string) TableDescriptor {
@@ -115,6 +132,7 @@ func createSystemTable(id ID, cmd string) TableDescriptor {
 		log.Fatal(err)
 	}
 
+	NumUsedSystemIDs++
 	return desc
 }
 
@@ -129,13 +147,17 @@ func GetInitialSystemValues() []proto.KeyValue {
 		{SystemDB.ID, &NamespaceTable},
 		{SystemDB.ID, &DescriptorTable},
 		{SystemDB.ID, &UsersTable},
+		{SystemDB.ID, &ZonesTable},
 	}
 
+	// Initial kv pairs:
+	// - ID generator
+	// - 2 per table/database
 	numEntries := 1 + len(systemData)*2
 	ret := make([]proto.KeyValue, numEntries, numEntries)
 	i := 0
 
-	// We reserve the system IDs.
+	// Descriptor ID generator.
 	value := proto.Value{}
 	value.SetInteger(int64(MaxReservedDescID + 1))
 	ret[i] = proto.KeyValue{

sql/system_test.go

@@ -0,0 +1,35 @@
+// Copyright 2015 The Cockroach Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+// implied. See the License for the specific language governing
+// permissions and limitations under the License. See the AUTHORS file
+// for names of contributors.
+//
+// Author: Marc Berhault (marc@cockroachlabs.com)
+
+package sql_test
+
+import (
+	"testing"
+
+	"github.com/cockroachdb/cockroach/sql"
+	"github.com/cockroachdb/cockroach/util/leaktest"
+)
+
+func TestInitialKeys(t *testing.T) {
+	defer leaktest.AfterTest(t)
+
+	kv := sql.GetInitialSystemValues()
+	// IDGenerator + 2 for each table/database.
+	if actual, expected := len(kv), 1+2*sql.NumUsedSystemIDs; actual != expected {
+		t.Fatalf("Wrong number of initial sql kv pairs: %d, wanted %d", actual, expected)
+	}
+}

sql/testdata/system

@@ -10,6 +10,7 @@ SHOW TABLES FROM system
 descriptor
 namespace
 users
+zones
 
 query ITTB
 EXPLAIN (DEBUG) SELECT * FROM system.namespace
@@ -19,6 +20,7 @@ EXPLAIN (DEBUG) SELECT * FROM system.namespace
 2 /namespace/primary/1/'descriptor'/id 3    true
 3 /namespace/primary/1/'namespace'/id  2    true
 4 /namespace/primary/1/'users'/id      4    true
+5 /namespace/primary/1/'zones'/id      5    true
 
 query ITI
 SELECT * FROM system.namespace
@@ -28,6 +30,7 @@ SELECT * FROM system.namespace
 1 descriptor 3
 1 namespace  2
 1 users      4
+1 zones      5
 
 query I
 SELECT id FROM system.descriptor
@@ -36,6 +39,7 @@ SELECT id FROM system.descriptor
 2
 3
 4
+5
 1000
 
 # Verify format of system tables.
@@ -58,6 +62,12 @@ SHOW COLUMNS FROM system.users;
 username       STRING true
 hashedPassword BYTES  true
 
+query TTT
+SHOW COLUMNS FROM system.zones;
+----
+id     INT   true
+config BYTES true
+
 # Verify default privileges on system tables.
 query TTT
 SHOW GRANTS ON DATABASE system
@@ -79,6 +89,11 @@ SHOW GRANTS ON system.users
 ----
 users root DELETE,GRANT,INSERT,SELECT,UPDATE
 
+query TTT
+SHOW GRANTS ON system.zones
+----
+zones root DELETE,GRANT,INSERT,SELECT,UPDATE
+
 # Non-root users can have privileges on system objects, but limited to GRANT, SELECT.
 statement error user testuser must not have ALL privileges on system objects
 GRANT ALL ON DATABASE system TO testuser

storage/replica.go

@@ -22,6 +22,7 @@ package storage
 
 import (
 	"bytes"
+	"crypto/sha1"
 	"crypto/sha256"
 	"fmt"
 	"math/rand"
@@ -202,7 +203,7 @@ type Replica struct {
 	// Last index applied to the state machine. Updated atomically.
 	appliedIndex uint64
 	configHashes map[int][]byte // Config map sha256 hashes @ last gossip
-	systemDBHash []byte         // sha256 hash of the system config @ last gossip
+	systemDBHash []byte         // sha1 hash of the system config @ last gossip
 	lease        unsafe.Pointer // Information for leader lease, updated atomically
 	llMu         sync.Mutex     // Synchronizes readers' requests for leader lease
 	respCache    *ResponseCache // Provides idempotence for retries
@@ -1298,20 +1299,22 @@ func (r *Replica) maybeGossipSystemConfigLocked() {
 
 	ctx := r.context()
 	// TODO(marc): check for bad split in the middle of the SystemDB span.
-	systemConfig, hash, err := loadSystemConfig(r.rm.Engine())
+	kvs, hash, err := loadSystemDBSpan(r.rm.Engine())
 	if err != nil {
-		log.Errorc(ctx, "could not load system config: %s", err)
+		log.Errorc(ctx, "could not load SystemDB span: %s", err)
 		return
 	}
 	if bytes.Equal(r.systemDBHash, hash) {
 		return
 	}
 
+	cfg := &config.SystemConfig{Values: kvs}
+
 	r.systemDBHash = hash
 	if log.V(1) {
 		log.Infoc(ctx, "gossiping system config from store %d, range %d", r.rm.StoreID(), r.Desc().RangeID)
 	}
-	if err := r.rm.Gossip().AddInfoProto(gossip.KeySystemDB, systemConfig, 0); err != nil {
+	if err := r.rm.Gossip().AddInfoProto(gossip.KeySystemDB, cfg, 0); err != nil {
 		log.Errorc(ctx, "failed to gossip system config: %s", err)
 	}
 }
@@ -1534,23 +1537,21 @@ func loadConfigMap(eng engine.Engine, keyPrefix proto.Key, configI gogoproto.Mes
 	return m, sha.Sum(nil), err
 }
 
-// loadSystemConfig scans the entire SystemDB span and puts the set of key/value
-// pairs in the config, generating a sha256 sum.
-func loadSystemConfig(eng engine.Engine) (*config.SystemConfig, []byte, error) {
+// loadSystemDBSpan scans the entire SystemDB span and returns the full list of
+// key/value pairs along with the sha1 checksum of the contents (key and value).
+func loadSystemDBSpan(eng engine.Engine) ([]proto.KeyValue, []byte, error) {
 	// TODO(tschottdorf): Currently this does not handle intents well.
 	kvs, _, err := engine.MVCCScan(eng, keys.SystemDBSpan.Start, keys.SystemDBSpan.End,
 		0, proto.MaxTimestamp, true /* consistent */, nil)
 	if err != nil {
 		return nil, nil, err
 	}
-	cfg := &config.SystemConfig{
-		Values: kvs,
-	}
-	sha := sha256.New()
+	sha := sha1.New()
 	for _, kv := range kvs {
+		sha.Write(kv.Key)
 		sha.Write(kv.Value.Bytes)
 	}
-	return cfg, sha.Sum(nil), err
+	return kvs, sha.Sum(nil), err
 }
 
 // maybeAddToSplitQueue checks whether the current size of the range