*: unify the error definition

errors.toml

@@ -61,6 +61,11 @@ error = '''
 unsupported metrics type %v
 '''
 
+["PD:cgroup:ErrNoCPUControllerDetected"]
+error = '''
+no cpu controller detected
+'''
+
 ["PD:checker:ErrCheckerMergeAgain"]
 error = '''
 region will be merged again, %s
@@ -71,6 +76,36 @@ error = '''
 checker not found
 '''
 
+["PD:checker:ErrNoNewLeader"]
+error = '''
+no new leader
+'''
+
+["PD:checker:ErrNoStoreToAdd"]
+error = '''
+no store to add peer
+'''
+
+["PD:checker:ErrNoStoreToReplace"]
+error = '''
+no store to replace peer
+'''
+
+["PD:checker:ErrPeerCannotBeLeader"]
+error = '''
+peer cannot be leader
+'''
+
+["PD:checker:ErrPeerCannotBeWitness"]
+error = '''
+peer cannot be witness
+'''
+
+["PD:checker:ErrRegionNoLeader"]
+error = '''
+region no leader
+'''
+
 ["PD:client:ErrClientCreateTSOStream"]
 error = '''
 create TSO stream failed, %s
@@ -491,6 +526,116 @@ error = '''
 failed to unmarshal json
 '''
 
+["PD:keyspace:ErrExceedMaxEtcdTxnOps"]
+error = '''
+exceed max etcd txn operations
+'''
+
+["PD:keyspace:ErrIllegalOperation"]
+error = '''
+unknown operation
+'''
+
+["PD:keyspace:ErrKeyspaceExists"]
+error = '''
+keyspace already exists
+'''
+
+["PD:keyspace:ErrKeyspaceGroupExists"]
+error = '''
+keyspace group already exists
+'''
+
+["PD:keyspace:ErrKeyspaceGroupInMerging"]
+error = '''
+keyspace group %v is in merging state
+'''
+
+["PD:keyspace:ErrKeyspaceGroupInSplit"]
+error = '''
+keyspace group %v is in split state
+'''
+
+["PD:keyspace:ErrKeyspaceGroupNotEnoughReplicas"]
+error = '''
+not enough replicas in the keyspace group
+'''
+
+["PD:keyspace:ErrKeyspaceGroupNotExists"]
+error = '''
+keyspace group %v does not exist
+'''
+
+["PD:keyspace:ErrKeyspaceGroupNotInMerging"]
+error = '''
+keyspace group %v is not in merging state
+'''
+
+["PD:keyspace:ErrKeyspaceGroupNotInSplit"]
+error = '''
+keyspace group %v is not in split state
+'''
+
+["PD:keyspace:ErrKeyspaceGroupPrimaryNotFound"]
+error = '''
+primary of keyspace group does not exist
+'''
+
+["PD:keyspace:ErrKeyspaceGroupWithEmptyKeyspace"]
+error = '''
+keyspace group with empty keyspace
+'''
+
+["PD:keyspace:ErrKeyspaceNotFound"]
+error = '''
+keyspace does not exist
+'''
+
+["PD:keyspace:ErrKeyspaceNotInAnyKeyspaceGroup"]
+error = '''
+keyspace is not in any keyspace group
+'''
+
+["PD:keyspace:ErrKeyspaceNotInKeyspaceGroup"]
+error = '''
+keyspace is not in this keyspace group
+'''
+
+["PD:keyspace:ErrModifyDefaultKeyspace"]
+error = '''
+cannot modify default keyspace's state
+'''
+
+["PD:keyspace:ErrModifyDefaultKeyspaceGroup"]
+error = '''
+default keyspace group cannot be modified
+'''
+
+["PD:keyspace:ErrNoAvailableNode"]
+error = '''
+no available node
+'''
+
+["PD:keyspace:ErrNodeNotInKeyspaceGroup"]
+error = '''
+the tso node is not in this keyspace group
+'''
+
+["PD:keyspace:ErrRegionSplitFailed"]
+error = '''
+region split failed
+'''
+
+["PD:keyspace:ErrRegionSplitTimeout"]
+error = '''
+region split timeout
+'''
+
+["PD:keyspace:ErrUnsupportedOperationInKeyspace"]
+error = '''
+it's a unsupported operation
+'''
+
 ["PD:leveldb:ErrLevelDBClose"]
 error = '''
 close leveldb error
@@ -646,6 +791,11 @@ error = '''
 failed to unmarshal proto
 '''
 
+["PD:ratelimit:ErrMaxWaitingTasksExceeded"]
+error = '''
+max waiting tasks exceeded
+'''
+
 ["PD:region:ErrRegionAbnormalPeer"]
 error = '''
 region %v has abnormal peer
@@ -691,6 +841,11 @@ error = '''
 invalid group settings, please check the group name, priority and the number of resources
 '''
 
+["PD:scatter:ErrEmptyRegion"]
+error = '''
+empty region
+'''
+
 ["PD:schedule:ErrCreateOperator"]
 error = '''
 unable to create operator, %s

pkg/cgroup/cgroup_cpu.go

@@ -19,9 +19,9 @@ import (
 	"path/filepath"
 
 	"github.com/pingcap/errors"
-)
 
-var errNoCPUControllerDetected = errors.New("no cpu controller detected")
+	"github.com/tikv/pd/pkg/errs"
+)
 
 // Helper function for getCgroupCPU. Root is always "/", except in tests.
 func getCgroupCPUHelper(root string) (CPUUsage, error) {
@@ -32,7 +32,7 @@ func getCgroupCPUHelper(root string) (CPUUsage, error) {
 
 	// No CPU controller detected
 	if path == "" {
-		return CPUUsage{}, errNoCPUControllerDetected
+		return CPUUsage{}, errs.ErrNoCPUControllerDetected
 	}
 
 	mount, ver, err := getCgroupDetails(filepath.Join(root, procPathMountInfo), path, "cpu,cpuacct")

pkg/cgroup/cgroup_cpu_test.go

@@ -26,6 +26,8 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
+
+	"github.com/tikv/pd/pkg/errs"
 )
 
 func checkKernelVersionNewerThan(re *require.Assertions, t *testing.T, major, minor int) bool {
@@ -82,7 +84,7 @@ func TestGetCgroupCPU(t *testing.T) {
 		}()
 	}
 	cpu, err := GetCgroupCPU()
-	if err == errNoCPUControllerDetected {
+	if err == errs.ErrNoCPUControllerDetected {
 		// for more information, please refer https://github.com/pingcap/tidb/pull/41347
 		if checkKernelVersionNewerThan(re, t, 4, 7) {
 			re.NoError(err, "linux version > v4.7 and err still happens")

pkg/errs/errno.go

@@ -140,8 +140,69 @@ var (
 
 // checker errors
 var (
-	ErrCheckerNotFound   = errors.Normalize("checker not found", errors.RFCCodeText("PD:checker:ErrCheckerNotFound"))
-	ErrCheckerMergeAgain = errors.Normalize("region will be merged again, %s", errors.RFCCodeText("PD:checker:ErrCheckerMergeAgain"))
+	ErrCheckerNotFound     = errors.Normalize("checker not found", errors.RFCCodeText("PD:checker:ErrCheckerNotFound"))
+	ErrCheckerMergeAgain   = errors.Normalize("region will be merged again, %s", errors.RFCCodeText("PD:checker:ErrCheckerMergeAgain"))
+	ErrNoStoreToAdd        = errors.Normalize("no store to add peer", errors.RFCCodeText("PD:checker:ErrNoStoreToAdd"))
+	ErrNoStoreToReplace    = errors.Normalize("no store to replace peer", errors.RFCCodeText("PD:checker:ErrNoStoreToReplace"))
+	ErrPeerCannotBeLeader  = errors.Normalize("peer cannot be leader", errors.RFCCodeText("PD:checker:ErrPeerCannotBeLeader"))
+	ErrPeerCannotBeWitness = errors.Normalize("peer cannot be witness", errors.RFCCodeText("PD:checker:ErrPeerCannotBeWitness"))
+	ErrNoNewLeader         = errors.Normalize("no new leader", errors.RFCCodeText("PD:checker:ErrNoNewLeader"))
+	ErrRegionNoLeader      = errors.Normalize("region no leader", errors.RFCCodeText("PD:checker:ErrRegionNoLeader"))
+)
+
+// scatter errors
+var (
+	ErrEmptyRegion = errors.Normalize("empty region", errors.RFCCodeText("PD:scatter:ErrEmptyRegion"))
+)
+
+// keyspace errors
+var (
+	// ErrKeyspaceNotFound is used to indicate target keyspace does not exist.
+	ErrKeyspaceNotFound = errors.Normalize("keyspace does not exist", errors.RFCCodeText("PD:keyspace:ErrKeyspaceNotFound"))
+	// ErrRegionSplitTimeout indices to split region timeout
+	ErrRegionSplitTimeout = errors.Normalize("region split timeout", errors.RFCCodeText("PD:keyspace:ErrRegionSplitTimeout"))
+	// ErrRegionSplitFailed indices to split region failed
+	ErrRegionSplitFailed = errors.Normalize("region split failed", errors.RFCCodeText("PD:keyspace:ErrRegionSplitFailed"))
+	// ErrKeyspaceExists indicates target keyspace already exists.
+	// It's used when creating a new keyspace.
+	ErrKeyspaceExists = errors.Normalize("keyspace already exists", errors.RFCCodeText("PD:keyspace:ErrKeyspaceExists"))
+	// ErrKeyspaceGroupExists indicates target keyspace group already exists.
+	ErrKeyspaceGroupExists = errors.Normalize("keyspace group already exists", errors.RFCCodeText("PD:keyspace:ErrKeyspaceGroupExists"))
+	// ErrKeyspaceNotInKeyspaceGroup is used to indicate target keyspace is not in this keyspace group.
+	ErrKeyspaceNotInKeyspaceGroup = errors.Normalize("keyspace is not in this keyspace group", errors.RFCCodeText("PD:keyspace:ErrKeyspaceNotInKeyspaceGroup"))
+	// ErrKeyspaceNotInAnyKeyspaceGroup is used to indicate target keyspace is not in any keyspace group.
+	ErrKeyspaceNotInAnyKeyspaceGroup = errors.Normalize("keyspace is not in any keyspace group", errors.RFCCodeText("PD:keyspace:ErrKeyspaceNotInAnyKeyspaceGroup"))
+	// ErrNodeNotInKeyspaceGroup is used to indicate the tso node is not in this keyspace group.
+	ErrNodeNotInKeyspaceGroup = errors.Normalize("the tso node is not in this keyspace group", errors.RFCCodeText("PD:keyspace:ErrNodeNotInKeyspaceGroup"))
+	// ErrKeyspaceGroupNotEnoughReplicas is used to indicate not enough replicas in the keyspace group.
+	ErrKeyspaceGroupNotEnoughReplicas = errors.Normalize("not enough replicas in the keyspace group", errors.RFCCodeText("PD:keyspace:ErrKeyspaceGroupNotEnoughReplicas"))
+	// ErrKeyspaceGroupWithEmptyKeyspace is used to indicate keyspace group with empty keyspace.
+	ErrKeyspaceGroupWithEmptyKeyspace = errors.Normalize("keyspace group with empty keyspace", errors.RFCCodeText("PD:keyspace:ErrKeyspaceGroupWithEmptyKeyspace"))
+	// ErrModifyDefaultKeyspaceGroup is used to indicate that default keyspace group cannot be modified.
+	ErrModifyDefaultKeyspaceGroup = errors.Normalize("default keyspace group cannot be modified", errors.RFCCodeText("PD:keyspace:ErrModifyDefaultKeyspaceGroup"))
+	// ErrNoAvailableNode is used to indicate no available node in the keyspace group.
+	ErrNoAvailableNode = errors.Normalize("no available node", errors.RFCCodeText("PD:keyspace:ErrNoAvailableNode"))
+	// ErrExceedMaxEtcdTxnOps is used to indicate the number of etcd txn operations exceeds the limit.
+	ErrExceedMaxEtcdTxnOps = errors.Normalize("exceed max etcd txn operations", errors.RFCCodeText("PD:keyspace:ErrExceedMaxEtcdTxnOps"))
+	// ErrModifyDefaultKeyspace is used to indicate that default keyspace cannot be modified.
+	ErrModifyDefaultKeyspace = errors.Normalize("cannot modify default keyspace's state", errors.RFCCodeText("PD:keyspace:ErrModifyDefaultKeyspace"))
+	// ErrIllegalOperation is used to indicate this is an illegal operation.
+	ErrIllegalOperation = errors.Normalize("unknown operation", errors.RFCCodeText("PD:keyspace:ErrIllegalOperation"))
+	// ErrUnsupportedOperationInKeyspace is used to indicate this is an unsupported operation.
+	ErrUnsupportedOperationInKeyspace = errors.Normalize("it's a unsupported operation", errors.RFCCodeText("PD:keyspace:ErrUnsupportedOperationInKeyspace"))
+	// ErrKeyspaceGroupPrimaryNotFound is used to indicate primary of target keyspace group does not exist.
+	ErrKeyspaceGroupPrimaryNotFound = errors.Normalize("primary of keyspace group does not exist", errors.RFCCodeText("PD:keyspace:ErrKeyspaceGroupPrimaryNotFound"))
+	// ErrKeyspaceGroupNotExists is used to indicate target keyspace group does not exist.
+	ErrKeyspaceGroupNotExists = errors.Normalize("keyspace group %v does not exist", errors.RFCCodeText("PD:keyspace:ErrKeyspaceGroupNotExists"))
+	// ErrKeyspaceGroupInSplit is used to indicate target keyspace group is in split state.
+	ErrKeyspaceGroupInSplit = errors.Normalize("keyspace group %v is in split state", errors.RFCCodeText("PD:keyspace:ErrKeyspaceGroupInSplit"))
+	// ErrKeyspaceGroupNotInSplit is used to indicate target keyspace group is not in split state.
+	ErrKeyspaceGroupNotInSplit = errors.Normalize("keyspace group %v is not in split state", errors.RFCCodeText("PD:keyspace:ErrKeyspaceGroupNotInSplit"))
+	// ErrKeyspaceGroupInMerging is used to indicate target keyspace group is in merging state.
+	ErrKeyspaceGroupInMerging = errors.Normalize("keyspace group %v is in merging state", errors.RFCCodeText("PD:keyspace:ErrKeyspaceGroupInMerging"))
+	// ErrKeyspaceGroupNotInMerging is used to indicate target keyspace group is not in merging state.
+	ErrKeyspaceGroupNotInMerging = errors.Normalize("keyspace group %v is not in merging state", errors.RFCCodeText("PD:keyspace:ErrKeyspaceGroupNotInMerging"))
+	// errKeyspaceGroupNotInMerging is used to indicate target keyspace group is not in merging state.
 )
 
 // diagnostic errors
@@ -229,6 +290,16 @@ var (
 	ErrBytesToUint64 = errors.Normalize("invalid data, must 8 bytes, but %d", errors.RFCCodeText("PD:typeutil:ErrBytesToUint64"))
 )
 
+// cgroup errors
+var (
+	ErrNoCPUControllerDetected = errors.Normalize("no cpu controller detected", errors.RFCCodeText("PD:cgroup:ErrNoCPUControllerDetected"))
+)
+
+// ratelimit errors
+var (
+	ErrMaxWaitingTasksExceeded = errors.Normalize("max waiting tasks exceeded", errors.RFCCodeText("PD:ratelimit:ErrMaxWaitingTasksExceeded"))
+)
+
 // The third-party project error.
 // url errors
 var (

pkg/gc/safepoint_v2.go

@@ -25,6 +25,7 @@ import (
 	"github.com/pingcap/kvproto/pkg/keyspacepb"
 	"github.com/pingcap/log"
 
+	"github.com/tikv/pd/pkg/errs"
 	"github.com/tikv/pd/pkg/keyspace"
 	"github.com/tikv/pd/pkg/slice"
 	"github.com/tikv/pd/pkg/storage/endpoint"
@@ -101,7 +102,7 @@ func (manager *SafePointV2Manager) checkKeyspace(keyspaceID uint32, updateReques
 		}
 		// If a keyspace does not exist, then loading its gc safe point is prohibited.
 		if meta == nil {
-			return keyspace.ErrKeyspaceNotFound
+			return errs.ErrKeyspaceNotFound
 		}
 		// If keyspace's state does not permit updating safe point, we return error.
 		if updateRequest && !slice.Contains(allowUpdateSafePoint, meta.GetState()) {