// newTxn begins a transaction. For testing purposes, this comes with a ID
// pre-initialized, but with the Writing flag set to false.
func newTxn(clock *hlc.Clock, baseKey proto.Key) *proto.Transaction {
f, l, fun := caller.Lookup(1)
name := fmt.Sprintf("%s:%d %s", f, l, fun)
txn := proto.NewTransaction("test", baseKey, 1, proto.SERIALIZABLE, clock.Now(), clock.MaxOffset().Nanoseconds())
txn.Name = name
return txn
}
// maybeBeginTxn begins a new transaction if a txn has been specified
// in the request but has a nil ID. The new transaction is initialized
// using the name and isolation in the otherwise uninitialized txn.
// The Priority, if non-zero is used as a minimum.
func (tc *TxnCoordSender) maybeBeginTxn(header *proto.RequestHeader) {
if header.Txn != nil {
if len(header.Txn.ID) == 0 {
newTxn := proto.NewTransaction(header.Txn.Name, keys.KeyAddress(header.Key), header.GetUserPriority(),
header.Txn.Isolation, tc.clock.Now(), tc.clock.MaxOffset().Nanoseconds())
// Use existing priority as a minimum. This is used on transaction
// aborts to ratchet priority when creating successor transaction.
if newTxn.Priority < header.Txn.Priority {
newTxn.Priority = header.Txn.Priority
}
header.Txn = newTxn
}
}
}
// maybeBeginTxn begins a new transaction if a txn has been specified
// in the request but has a nil ID. The new transaction is initialized
// using the name and isolation in the otherwise uninitialized txn.
// The Priority, if non-zero is used as a minimum.
func (tc *TxnCoordSender) maybeBeginTxn(ba *proto.BatchRequest) {
if ba.Txn == nil {
return
}
if len(ba.Requests) == 0 {
panic("empty batch with txn")
}
if len(ba.Txn.ID) == 0 {
// TODO(tschottdorf): should really choose the first txn write here.
firstKey := ba.Requests[0].GetInner().Header().Key
newTxn := proto.NewTransaction(ba.Txn.Name, keys.KeyAddress(firstKey), ba.GetUserPriority(),
ba.Txn.Isolation, tc.clock.Now(), tc.clock.MaxOffset().Nanoseconds())
// Use existing priority as a minimum. This is used on transaction
// aborts to ratchet priority when creating successor transaction.
if newTxn.Priority < ba.Txn.Priority {
newTxn.Priority = ba.Txn.Priority
}
ba.Txn = newTxn
}
}
// TestRangeLookupWithOpenTransaction verifies that range lookups are
// done in such a way (e.g. using inconsistent reads) that they
// proceed in the event that a write intent is extant at the meta
// index record being read.
func TestRangeLookupWithOpenTransaction(t *testing.T) {
defer leaktest.AfterTest(t)
s := server.StartTestServer(t)
defer s.Stop()
db := createTestClient(t, s.ServingAddr())
// Create an intent on the meta1 record by writing directly to the
// engine.
key := keys.MakeKey(keys.Meta1Prefix, proto.KeyMax)
now := s.Clock().Now()
txn := proto.NewTransaction("txn", proto.Key("foobar"), 0, proto.SERIALIZABLE, now, 0)
if err := engine.MVCCPutProto(s.Ctx.Engines[0], nil, key, now, txn, &proto.RangeDescriptor{}); err != nil {
t.Fatal(err)
}
// Now, with an intent pending, attempt (asynchronously) to read
// from an arbitrary key. This will cause the distributed sender to
// do a range lookup, which will encounter the intent. We're
// verifying here that the range lookup doesn't fail with a write
// intent error. If it did, it would go into a deadloop attempting
// to push the transaction, which in turn requires another range
// lookup, etc, ad nauseam.
success := make(chan struct{})
go func() {
if _, err := db.Get("a"); err != nil {
t.Fatal(err)
}
close(success)
}()
select {
case <-success:
// Hurrah!
case <-time.After(5 * time.Second):
t.Errorf("get request did not succeed in face of range metadata intent")
}
}
// newTxn begins a transaction.
func newTxn(clock *hlc.Clock, baseKey proto.Key) *proto.Transaction {
return proto.NewTransaction("test", baseKey, 1, proto.SERIALIZABLE, clock.Now(), clock.MaxOffset().Nanoseconds())
}