// TestTxnCoordSenderAddIntentOnError verifies that intents are tracked if
// the transaction is, even on error.
func TestTxnCoordSenderAddIntentOnError(t *testing.T) {
defer leaktest.AfterTest(t)()
s, sender := createTestDB(t)
defer s.Stop()
// Create a transaction with intent at "a".
key := roachpb.Key("x")
txn := client.NewTxn(context.Background(), *s.DB)
// Write so that the coordinator begins tracking this txn.
if err := txn.Put("x", "y"); err != nil {
t.Fatal(err)
}
err, ok := txn.CPut(key, []byte("x"), []byte("born to fail")).(*roachpb.ConditionFailedError)
if !ok {
t.Fatal(err)
}
sender.Lock()
txnID := *txn.Proto.ID
intentSpans, _ := roachpb.MergeSpans(sender.txns[txnID].keys)
expSpans := []roachpb.Span{{Key: key, EndKey: []byte("")}}
equal := !reflect.DeepEqual(intentSpans, expSpans)
sender.Unlock()
if err := txn.Rollback(); err != nil {
t.Fatal(err)
}
if !equal {
t.Fatalf("expected stored intents %v, got %v", expSpans, intentSpans)
}
}
// TestTxnCoordSenderKeyRanges verifies that multiple requests to same or
// overlapping key ranges causes the coordinator to keep track only of
// the minimum number of ranges.
func TestTxnCoordSenderKeyRanges(t *testing.T) {
defer leaktest.AfterTest(t)()
ranges := []struct {
start, end roachpb.Key
}{
{roachpb.Key("a"), roachpb.Key(nil)},
{roachpb.Key("a"), roachpb.Key(nil)},
{roachpb.Key("aa"), roachpb.Key(nil)},
{roachpb.Key("b"), roachpb.Key(nil)},
{roachpb.Key("aa"), roachpb.Key("c")},
{roachpb.Key("b"), roachpb.Key("c")},
}
s, sender := createTestDB(t)
defer s.Stop()
defer teardownHeartbeats(sender)
txn := client.NewTxn(context.Background(), *s.DB)
for _, rng := range ranges {
if rng.end != nil {
if err := txn.DelRange(rng.start, rng.end); err != nil {
t.Fatal(err)
}
} else {
if err := txn.Put(rng.start, []byte("value")); err != nil {
t.Fatal(err)
}
}
}
txnID := *txn.Proto.ID
// Verify that the transaction metadata contains only two entries
// in its "keys" range group. "a" and range "aa"-"c".
txnMeta, ok := sender.txns[txnID]
if !ok {
t.Fatalf("expected a transaction to be created on coordinator")
}
keys, _ := roachpb.MergeSpans(txnMeta.keys)
if len(keys) != 2 {
t.Errorf("expected 2 entries in keys range group; got %v", keys)
}
}
// tryAsyncAbort (synchronously) grabs a copy of the txn proto and the intents
// (which it then clears from txnMeta), and asynchronously tries to abort the
// transaction.
func (tc *TxnCoordSender) tryAsyncAbort(txnID uuid.UUID) {
tc.Lock()
txnMeta := tc.txns[txnID]
// Clone the intents and the txn to avoid data races.
intentSpans, _ := roachpb.MergeSpans(append([]roachpb.Span(nil), txnMeta.keys...))
txnMeta.keys = nil
txn := txnMeta.txn.Clone()
tc.Unlock()
// Since we don't hold the lock continuously, it's possible that two aborts
// raced here. That's fine (and probably better than the alternative, which
// is missing new intents sometimes).
if txn.Status != roachpb.PENDING {
return
}
ba := roachpb.BatchRequest{}
ba.Txn = &txn
et := &roachpb.EndTransactionRequest{
Span: roachpb.Span{
Key: txn.Key,
},
Commit: false,
IntentSpans: intentSpans,
}
ba.Add(et)
ctx := tc.AnnotateCtx(context.TODO())
if err := tc.stopper.RunAsyncTask(ctx, func(ctx context.Context) {
// Use the wrapped sender since the normal Sender does not allow
// clients to specify intents.
if _, pErr := tc.wrapped.Send(ctx, ba); pErr != nil {
if log.V(1) {
log.Warningf(ctx, "abort due to inactivity failed for %s: %s ", txn, pErr)
}
}
}); err != nil {
log.Warning(ctx, err)
}
}
// Send implements the batch.Sender interface. If the request is part of a
// transaction, the TxnCoordSender adds the transaction to a map of active
// transactions and begins heartbeating it. Every subsequent request for the
// same transaction updates the lastUpdate timestamp to prevent live
// transactions from being considered abandoned and garbage collected.
// Read/write mutating requests have their key or key range added to the
// transaction's interval tree of key ranges for eventual cleanup via resolved
// write intents; they're tagged to an outgoing EndTransaction request, with
// the receiving replica in charge of resolving them.
func (tc *TxnCoordSender) Send(
ctx context.Context, ba roachpb.BatchRequest,
) (*roachpb.BatchResponse, *roachpb.Error) {
// Start new or pick up active trace. From here on, there's always an active
// Trace, though its overhead is small unless it's sampled.
sp := opentracing.SpanFromContext(ctx)
var tracer opentracing.Tracer
if sp == nil {
tracer = tc.AmbientContext.Tracer
sp = tracer.StartSpan(opTxnCoordSender)
defer sp.Finish()
ctx = opentracing.ContextWithSpan(ctx, sp)
} else {
tracer = sp.Tracer()
}
startNS := tc.clock.PhysicalNow()
if ba.Txn != nil {
// If this request is part of a transaction...
if err := tc.maybeBeginTxn(&ba); err != nil {
return nil, roachpb.NewError(err)
}
txnID := *ba.Txn.ID
// Associate the txnID with the trace. We need to do this after the
// maybeBeginTxn call. We set both a baggage item and a tag because only
// tags show up in the LIghtstep UI.
txnIDStr := txnID.String()
sp.SetTag("txnID", txnIDStr)
sp.SetBaggageItem("txnID", txnIDStr)
var et *roachpb.EndTransactionRequest
var hasET bool
{
var rArgs roachpb.Request
rArgs, hasET = ba.GetArg(roachpb.EndTransaction)
if hasET {
et = rArgs.(*roachpb.EndTransactionRequest)
if len(et.Key) != 0 {
return nil, roachpb.NewErrorf("EndTransaction must not have a Key set")
}
et.Key = ba.Txn.Key
if len(et.IntentSpans) > 0 {
// TODO(tschottdorf): it may be useful to allow this later.
// That would be part of a possible plan to allow txns which
// write on multiple coordinators.
return nil, roachpb.NewErrorf("client must not pass intents to EndTransaction")
}
}
}
if pErr := func() *roachpb.Error {
tc.Lock()
defer tc.Unlock()
if pErr := tc.maybeRejectClientLocked(ctx, *ba.Txn); pErr != nil {
return pErr
}
if !hasET {
return nil
}
// Everything below is carried out only when trying to commit.
// Populate et.IntentSpans, taking into account both any existing
// and new writes, and taking care to perform proper deduplication.
txnMeta := tc.txns[txnID]
distinctSpans := true
if txnMeta != nil {
et.IntentSpans = txnMeta.keys
// Defensively set distinctSpans to false if we had any previous
// requests in this transaction. This effectively limits the distinct
// spans optimization to 1pc transactions.
distinctSpans = len(txnMeta.keys) == 0
}
// We can't pass in a batch response here to better limit the key
// spans as we don't know what is going to be affected. This will
// affect queries such as `DELETE FROM my.table LIMIT 10` when
// executed as a 1PC transaction. e.g.: a (BeginTransaction,
// DeleteRange, EndTransaction) batch.
ba.IntentSpanIterate(nil, func(key, endKey roachpb.Key) {
et.IntentSpans = append(et.IntentSpans, roachpb.Span{
Key: key,
EndKey: endKey,
})
})
// TODO(peter): Populate DistinctSpans on all batches, not just batches
// which contain an EndTransactionRequest.
var distinct bool
// The request might already be used by an outgoing goroutine, so
// we can't safely mutate anything in-place (as MergeSpans does).
et.IntentSpans = append([]roachpb.Span(nil), et.IntentSpans...)
et.IntentSpans, distinct = roachpb.MergeSpans(et.IntentSpans)
ba.Header.DistinctSpans = distinct && distinctSpans
if len(et.IntentSpans) == 0 {
// If there aren't any intents, then there's factually no
// transaction to end. Read-only txns have all of their state
// in the client.
return roachpb.NewErrorf("cannot commit a read-only transaction")
}
if txnMeta != nil {
txnMeta.keys = et.IntentSpans
}
return nil
}(); pErr != nil {
return nil, pErr
}
if hasET && log.V(1) {
for _, intent := range et.IntentSpans {
log.Eventf(ctx, "intent: [%s,%s)", intent.Key, intent.EndKey)
}
}
}
// Embed the trace metadata into the header for use by RPC recipients. We need
// to do this after the maybeBeginTxn call above.
// TODO(tschottdorf): To get rid of the spurious alloc below we need to
// implement the carrier interface on ba.Header or make Span non-nullable,
// both of which force all of ba on the Heap. It's already there, so may
// not be a big deal, but ba should live on the stack. Also not easy to use
// a buffer pool here since anything that goes into the RPC layer could be
// used by goroutines we didn't wait for.
if ba.TraceContext == nil {
ba.TraceContext = &tracing.SpanContextCarrier{}
} else {
// We didn't make this object but are about to mutate it, so we
// have to take a copy - the original might already have been
// passed to the RPC layer.
ba.TraceContext = protoutil.Clone(ba.TraceContext).(*tracing.SpanContextCarrier)
}
if err := tracer.Inject(sp.Context(), basictracer.Delegator, ba.TraceContext); err != nil {
return nil, roachpb.NewError(err)
}
// Send the command through wrapped sender, taking appropriate measures
// on error.
var br *roachpb.BatchResponse
{
var pErr *roachpb.Error
br, pErr = tc.wrapped.Send(ctx, ba)
if _, ok := pErr.GetDetail().(*roachpb.OpRequiresTxnError); ok {
// TODO(tschottdorf): needs to keep the trace.
br, pErr = tc.resendWithTxn(ba)
}
if pErr = tc.updateState(ctx, startNS, ba, br, pErr); pErr != nil {
log.Eventf(ctx, "error: %s", pErr)
return nil, pErr
}
}
if br.Txn == nil {
return br, nil
}
if _, ok := ba.GetArg(roachpb.EndTransaction); !ok {
return br, nil
}
// If the --linearizable flag is set, we want to make sure that
// all the clocks in the system are past the commit timestamp
// of the transaction. This is guaranteed if either
// - the commit timestamp is MaxOffset behind startNS
// - MaxOffset ns were spent in this function
// when returning to the client. Below we choose the option
// that involves less waiting, which is likely the first one
// unless a transaction commits with an odd timestamp.
if tsNS := br.Txn.Timestamp.WallTime; startNS > tsNS {
startNS = tsNS
}
sleepNS := tc.clock.MaxOffset() -
time.Duration(tc.clock.PhysicalNow()-startNS)
if tc.linearizable && sleepNS > 0 {
defer func() {
if log.V(1) {
log.Infof(ctx, "%v: waiting %s on EndTransaction for linearizability", br.Txn.Short(), util.TruncateDuration(sleepNS, time.Millisecond))
}
time.Sleep(sleepNS)
}()
}
if br.Txn.Status != roachpb.PENDING {
tc.Lock()
tc.cleanupTxnLocked(ctx, *br.Txn)
tc.Unlock()
}
return br, nil
}