// Locates the region in which the given row key for the given table is.
func (c *client) locateRegion(ctx context.Context,
table, key []byte) (hrpc.RegionInfo, string, uint16, error) {
metaKey := createRegionSearchKey(table, key)
rpc, err := hrpc.NewGetBefore(ctx, metaTableName, metaKey, hrpc.Families(infoFamily))
if err != nil {
return nil, "", 0, err
}
rpc.SetRegion(c.metaRegionInfo)
resp, err := c.sendRPC(rpc)
if err != nil {
ch := c.metaRegionInfo.AvailabilityChan()
if ch != nil {
select {
case <-ch:
return c.locateRegion(ctx, table, key)
case <-rpc.Context().Done():
return nil, "", 0, ErrDeadline
}
} else {
return nil, "", 0, err
}
}
metaRow := resp.(*pb.GetResponse)
if metaRow.Result == nil {
return nil, "", 0, TableNotFound
}
reg, host, port, err := region.ParseRegionInfo(metaRow)
if err != nil {
return nil, "", 0, err
}
if !bytes.Equal(table, reg.Table()) {
// This would indicate a bug in HBase.
return nil, "", 0, fmt.Errorf("WTF: Meta returned an entry for the wrong table!"+
" Looked up table=%q key=%q got region=%s", table, key, reg)
} else if len(reg.StopKey()) != 0 &&
bytes.Compare(key, reg.StopKey()) >= 0 {
// This would indicate a hole in the meta table.
return nil, "", 0, fmt.Errorf("WTF: Meta returned an entry for the wrong region!"+
" Looked up table=%q key=%q got region=%s", table, key, reg)
}
return reg, host, port, nil
}
func TestRegionDiscovery(t *testing.T) {
client := newClient("~invalid.quorum~") // We shouldn't connect to ZK.
reg := client.getRegionFromCache([]byte("test"), []byte("theKey"))
if reg != nil {
t.Errorf("Found region %#v even though the cache was empty?!", reg)
}
// Inject a "test" table with a single region that covers the entire key
// space (both the start and stop keys are empty).
family := []byte("info")
metaRow := &pb.GetResponse{
Result: &pb.Result{Cell: []*pb.Cell{
&pb.Cell{
Row: []byte("test,,1234567890042.56f833d5569a27c7a43fbf547b4924a4."),
Family: family,
Qualifier: []byte("regioninfo"),
Value: []byte("PBUF\b\xc4\xcd\xe9\x99\xe0)\x12\x0f\n\adefault\x12\x04test" +
"\x1a\x00\"\x00(\x000\x008\x00"),
},
&pb.Cell{
Row: []byte("test,,1234567890042.56f833d5569a27c7a43fbf547b4924a4."),
Family: family,
Qualifier: []byte("seqnumDuringOpen"),
Value: []byte("\x00\x00\x00\x00\x00\x00\x00\x02"),
},
&pb.Cell{
Row: []byte("test,,1234567890042.56f833d5569a27c7a43fbf547b4924a4."),
Family: family,
Qualifier: []byte("server"),
Value: []byte("localhost:50966"),
},
&pb.Cell{
Row: []byte("test,,1234567890042.56f833d5569a27c7a43fbf547b4924a4."),
Family: family,
Qualifier: []byte("serverstartcode"),
Value: []byte("\x00\x00\x01N\x02\x92R\xb1"),
},
}}}
reg, _, _, err := region.ParseRegionInfo(metaRow)
if err != nil {
t.Fatalf("Failed to discover region: %s", err)
}
client.regions.put(reg)
reg = client.getRegionFromCache([]byte("test"), []byte("theKey"))
if reg == nil {
t.Fatal("Region not found even though we injected it in the cache.")
}
expected := region.NewInfo(
[]byte("test"),
[]byte("test,,1234567890042.56f833d5569a27c7a43fbf547b4924a4."),
nil,
nil,
)
if !bytes.Equal(reg.Table(), expected.Table()) ||
!bytes.Equal(reg.Name(), expected.Name()) ||
!bytes.Equal(reg.StartKey(), expected.StartKey()) ||
!bytes.Equal(reg.StopKey(), expected.StopKey()) {
t.Errorf("Found region %#v \nbut expected %#v", reg, expected)
}
reg = client.getRegionFromCache([]byte("notfound"), []byte("theKey"))
if reg != nil {
t.Errorf("Found region %#v even though this table doesn't exist", reg)
}
}