// withEventLogInternal embeds a trace.EventLog in the context, causing future
// logging and event calls to go to the EventLog. The current context must not
// have an existing open span.
func withEventLogInternal(ctx context.Context, eventLog trace.EventLog) context.Context {
if opentracing.SpanFromContext(ctx) != nil {
panic("event log under span")
}
val := &ctxEventLog{eventLog: eventLog}
return context.WithValue(ctx, ctxEventLogKey{}, val)
}
// SpanFromContext wraps opentracing.SpanFromContext so that the returned
// Span is never nil.
func SpanFromContext(ctx context.Context) opentracing.Span {
sp := opentracing.SpanFromContext(ctx)
if sp == nil {
return NoopSpan()
}
return sp
}
// EnsureContext checks whether the given context.Context contains a Span. If
// not, it creates one using the provided Tracer and wraps it in the returned
// Span. The returned closure must be called after the request has been fully
// processed.
func EnsureContext(ctx context.Context, tracer opentracing.Tracer) (context.Context, func()) {
_, _, funcName := caller.Lookup(1)
if opentracing.SpanFromContext(ctx) == nil {
sp := tracer.StartSpan(funcName)
return opentracing.ContextWithSpan(ctx, sp), sp.Finish
}
return ctx, func() {}
}
// ChildSpan opens a span as a child of the current span in the context (if
// there is one).
//
// Returns the new context and the new span (if any). The span should be
// closed via FinishSpan.
func ChildSpan(ctx context.Context, opName string) (context.Context, opentracing.Span) {
span := opentracing.SpanFromContext(ctx)
if span == nil {
return ctx, nil
}
newSpan := span.Tracer().StartSpan(opName, opentracing.ChildOf(span.Context()))
return opentracing.ContextWithSpan(ctx, newSpan), newSpan
}
// SpanFromContext returns the Span obtained from the context or, if none is
// found, a new one started through the tracer. Callers should call (or defer)
// the returned cleanup func as well to ensure that the span is Finish()ed, but
// callers should *not* attempt to call Finish directly -- in the case where the
// span was obtained from the context, it is not the caller's to Finish.
func SpanFromContext(opName string, tracer opentracing.Tracer, ctx context.Context) (opentracing.Span, func()) {
sp := opentracing.SpanFromContext(ctx)
if sp == nil {
sp = tracer.StartSpan(opName)
return sp, sp.Finish
}
return sp, func() {}
}
// SetFlowRequestTrace populates req.Trace with the context of the current Span
// in the context (if any).
func SetFlowRequestTrace(ctx context.Context, req *SetupFlowRequest) error {
sp := opentracing.SpanFromContext(ctx)
if sp == nil {
return nil
}
req.TraceContext = &tracing.SpanContextCarrier{}
tracer := sp.Tracer()
return tracer.Inject(sp.Context(), basictracer.Delegator, req.TraceContext)
}
// AnnotateCtx annotates a given context with the information in AmbientContext:
// - the EventLog is embedded in the context if the context doesn't already
// have en event log or an open trace.
// - the log tags in AmbientContext are added (if ctx doesn't already have them).
//
// For background operations, context.Background() should be passed; however, in
// that case it is strongly recommended to open a span if possible (using
// AnnotateCtxWithSpan).
func (ac *AmbientContext) AnnotateCtx(ctx context.Context) context.Context {
// TODO(radu): We could keep a cached context based off of
// context.Background() to avoid allocations in that case.
if ac.eventLog != nil && opentracing.SpanFromContext(ctx) == nil && eventLogFromCtx(ctx) == nil {
ctx = embedCtxEventLog(ctx, ac.eventLog)
}
if ac.tags != nil {
ctx = copyTagChain(ctx, ac.tags)
}
return ctx
}
// getSpanOrEventLog returns the current Span. If there is no Span, it returns
// the current ctxEventLog. If neither (or the Span is NoopTracer), returns
// false.
func getSpanOrEventLog(ctx context.Context) (opentracing.Span, *ctxEventLog, bool) {
if sp := opentracing.SpanFromContext(ctx); sp != nil {
if sp.Tracer() == noopTracer {
return nil, nil, false
}
return sp, nil, true
}
if el := eventLogFromCtx(ctx); el != nil {
return nil, el, true
}
return nil, nil, false
}
func newFlow(flowCtx FlowCtx, flowReg *flowRegistry, simpleFlowConsumer RowReceiver) *Flow {
if opentracing.SpanFromContext(flowCtx.Context) == nil {
panic("flow context has no span")
}
flowCtx.Context = log.WithLogTagStr(flowCtx.Context, "f", flowCtx.id.Short())
return &Flow{
FlowCtx: flowCtx,
flowRegistry: flowReg,
simpleFlowConsumer: simpleFlowConsumer,
status: FlowNotStarted,
}
}
// sendSingleRange gathers and rearranges the replicas, and makes an RPC call.
func (ds *DistSender) sendSingleRange(
ctx context.Context, ba roachpb.BatchRequest, desc *roachpb.RangeDescriptor,
) (*roachpb.BatchResponse, *roachpb.Error) {
// Hack: avoid formatting the message passed to Span.LogEvent for
// opentracing.noopSpans. We can't actually tell if we have a noopSpan, but
// we can see if the span as a NoopTracer. Note that this particular
// invocation is expensive because we're pretty-printing keys.
//
// TODO(tschottdorf): This hack can go away when something like
// Span.LogEventf is added.
sp := opentracing.SpanFromContext(ctx)
if sp != nil && sp.Tracer() != (opentracing.NoopTracer{}) {
sp.LogEvent(fmt.Sprintf("sending RPC to [%s, %s)", desc.StartKey, desc.EndKey))
}
// Try to send the call.
replicas := newReplicaSlice(ds.gossip, desc)
// Rearrange the replicas so that those replicas with long common
// prefix of attributes end up first. If there's no prefix, this is a
// no-op.
order := ds.optimizeReplicaOrder(replicas)
// If this request needs to go to a leader and we know who that is, move
// it to the front.
if !(ba.IsReadOnly() && ba.ReadConsistency == roachpb.INCONSISTENT) {
if leader := ds.leaderCache.Lookup(roachpb.RangeID(desc.RangeID)); leader.StoreID > 0 {
if i := replicas.FindReplica(leader.StoreID); i >= 0 {
replicas.MoveToFront(i)
order = orderStable
}
}
}
// TODO(tschottdorf): should serialize the trace here, not higher up.
br, pErr := ds.sendRPC(ctx, desc.RangeID, replicas, order, ba)
if pErr != nil {
return nil, pErr
}
// If the reply contains a timestamp, update the local HLC with it.
if br.Error != nil && br.Error.Now != roachpb.ZeroTimestamp {
ds.clock.Update(br.Error.Now)
} else if br.Now != roachpb.ZeroTimestamp {
ds.clock.Update(br.Now)
}
// Untangle the error from the received response.
pErr = br.Error
br.Error = nil // scrub the response error
return br, pErr
}
// ForkCtxSpan checks if ctx has a Span open; if it does, it creates a new Span
// that follows from the original Span. This allows the resulting context to be
// used in an async task that might outlive the original operation.
//
// Returns the new context and the new span (if any). The span should be
// closed via FinishSpan.
func ForkCtxSpan(ctx context.Context, opName string) (context.Context, opentracing.Span) {
if span := opentracing.SpanFromContext(ctx); span != nil {
if span.BaggageItem(Snowball) == "1" {
// If we are doing snowball tracing, the span might outlive the snowball
// tracer (calling the record function when it is no longer legal to do
// so). Return a context with no span in this case.
return opentracing.ContextWithSpan(ctx, nil), nil
}
tr := span.Tracer()
newSpan := tr.StartSpan(opName, opentracing.FollowsFrom(span.Context()))
return opentracing.ContextWithSpan(ctx, newSpan), newSpan
}
return ctx, nil
}
// Cleanup should be called when the flow completes (after all processors and
// mailboxes exited).
func (f *Flow) Cleanup() {
if f.status == FlowFinished {
panic("flow cleanup called twice")
}
if log.V(1) {
log.Infof(f.Context, "cleaning up")
}
sp := opentracing.SpanFromContext(f.Context)
sp.Finish()
if f.status != FlowNotStarted {
f.flowRegistry.UnregisterFlow(f.id)
}
f.status = FlowFinished
}
// AnnotateCtxWithSpan annotates the given context with the information in
// AmbientContext (see AnnotateCtx) and opens a span.
//
// If the given context has a span, the new span is a child of that span.
// Otherwise, the Tracer in AmbientContext is used to create a new root span.
//
// The caller is responsible for closing the span (via Span.Finish).
func (ac *AmbientContext) AnnotateCtxWithSpan(
ctx context.Context, opName string,
) (context.Context, opentracing.Span) {
if ac.tags != nil {
ctx = copyTagChain(ctx, ac.tags)
}
var span opentracing.Span
if parentSpan := opentracing.SpanFromContext(ctx); parentSpan != nil {
tracer := parentSpan.Tracer()
span = tracer.StartSpan(opName, opentracing.ChildOf(parentSpan.Context()))
} else {
if ac.Tracer == nil {
panic("no tracer in AmbientContext for root span")
}
span = ac.Tracer.StartSpan(opName)
}
return opentracing.ContextWithSpan(ctx, span), span
}
// NewSession creates and initializes a new Session object.
// remote can be nil.
func NewSession(
ctx context.Context, args SessionArgs, e *Executor, remote net.Addr, memMetrics *MemoryMetrics,
) *Session {
ctx = e.AnnotateCtx(ctx)
s := &Session{
Database: args.Database,
SearchPath: []string{"pg_catalog"},
User: args.User,
Location: time.UTC,
virtualSchemas: e.virtualSchemas,
memMetrics: memMetrics,
}
cfg, cache := e.getSystemConfig()
s.planner = planner{
leaseMgr: e.cfg.LeaseManager,
systemConfig: cfg,
databaseCache: cache,
session: s,
execCfg: &e.cfg,
}
s.PreparedStatements = makePreparedStatements(s)
s.PreparedPortals = makePreparedPortals(s)
if opentracing.SpanFromContext(ctx) == nil {
remoteStr := "<admin>"
if remote != nil {
remoteStr = remote.String()
}
// Set up an EventLog for session events.
ctx = log.WithEventLog(ctx, fmt.Sprintf("sql [%s]", args.User), remoteStr)
s.finishEventLog = true
}
s.context, s.cancel = context.WithCancel(ctx)
return s
}
// Tracef looks for an opentracing.Trace in the context and formats and logs
// the given message to it on success.
func Tracef(ctx context.Context, format string, args ...interface{}) {
sp := opentracing.SpanFromContext(ctx)
if sp != nil && sp.Tracer() != noopTracer {
sp.LogEvent(fmt.Sprintf(format, args...))
}
}
// 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 and embed its trace metadata into
// header for use by RPC recipients. From here on, there's always an active
// Trace, though its overhead is small unless it's sampled.
sp := opentracing.SpanFromContext(ctx)
if sp == nil {
sp = tc.tracer.StartSpan(opTxnCoordSender)
defer sp.Finish()
ctx = opentracing.ContextWithSpan(ctx, sp)
}
// 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.Header.Trace == nil {
ba.Header.Trace = &tracing.Span{}
}
if err := tc.tracer.Inject(sp, basictracer.Delegator, ba.Trace); err != nil {
return nil, roachpb.NewError(err)
}
}
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
// Verify that if this Transaction is not read-only, we have it on file.
// If not, refuse further operations - the transaction was aborted due
// to a timeout or the client must have issued a write on another
// coordinator previously.
if ba.Txn.Writing {
tc.Lock()
_, ok := tc.txns[txnID]
tc.Unlock()
if !ok {
pErr := roachpb.NewErrorf("writing transaction timed out, was aborted, " +
"or ran on multiple coordinators")
return nil, pErr
}
}
if rArgs, ok := ba.GetArg(roachpb.EndTransaction); ok {
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")
}
tc.Lock()
txnMeta, metaOK := tc.txns[txnID]
{
// Populate et.IntentSpans, taking into account both existing
// writes (if any) and new writes in this batch, and taking
// care to perform proper deduplication.
var keys interval.RangeGroup
if metaOK {
keys = txnMeta.keys
} else {
keys = interval.NewRangeTree()
}
ba.IntentSpanIterate(func(key, endKey roachpb.Key) {
addKeyRange(keys, key, endKey)
})
et.IntentSpans = collectIntentSpans(keys)
}
tc.Unlock()
if len(et.IntentSpans) > 0 {
// All good, proceed.
} else if !metaOK {
// If we don't have the transaction, then this must be a retry
// by the client. We can no longer reconstruct a correct
// request so we must fail.
//
// TODO(bdarnell): if we had a GetTransactionStatus API then
// we could lookup the transaction and return either nil or
// TransactionAbortedError instead of this ambivalent error.
return nil, roachpb.NewErrorf("transaction is already committed or aborted")
}
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 nil, roachpb.NewErrorf("cannot commit a read-only transaction")
}
if log.V(1) {
for _, intent := range et.IntentSpans {
log.Trace(ctx, fmt.Sprintf("intent: [%s,%s)", intent.Key, intent.EndKey))
}
}
}
}
// 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(startNS, ctx, ba, br, pErr); pErr != nil {
log.Trace(ctx, fmt.Sprintf("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("%v: waiting %s on EndTransaction for linearizability", br.Txn.ID.Short(), util.TruncateDuration(sleepNS, time.Millisecond))
}
time.Sleep(sleepNS)
}()
}
if br.Txn.Status != roachpb.PENDING {
tc.cleanupTxn(ctx, *br.Txn)
}
return br, nil
}
// withEventLogInternal embeds a trace.EventLog in the context, causing future
// logging and event calls to go to the EventLog. The current context must not
// have an existing open span.
func withEventLogInternal(ctx context.Context, eventLog trace.EventLog) context.Context {
if opentracing.SpanFromContext(ctx) != nil {
panic("event log under span")
}
return embedCtxEventLog(ctx, &ctxEventLog{eventLog: eventLog})
}
// 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 and embed its trace metadata into
// header for use by RPC recipients. From here on, there's always an active
// Trace, though its overhead is small unless it's sampled.
sp := opentracing.SpanFromContext(ctx)
// TODO(radu): once contexts are plumbed correctly, we should use the Tracer
// from ctx.
tracer := tracing.TracerFromCtx(tc.ctx)
if sp == nil {
sp = tracer.StartSpan(opTxnCoordSender)
defer sp.Finish()
ctx = opentracing.ContextWithSpan(ctx, sp)
}
// 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.Header.Trace == nil {
ba.Header.Trace = &tracing.Span{}
} 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.Header.Trace = protoutil.Clone(ba.Header.Trace).(*tracing.Span)
}
if err := tracer.Inject(sp.Context(), basictracer.Delegator, ba.Trace); err != nil {
return nil, roachpb.NewError(err)
}
}
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)
}
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[*ba.Txn.ID]
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
}
ba.IntentSpanIterate(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.Tracef(ctx, "intent: [%s,%s)", intent.Key, intent.EndKey)
}
}
}
// 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(startNS, ctx, ba, br, pErr); pErr != nil {
log.Tracef(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.ID.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
}
// resetForNewSQLTxn (re)initializes the txnState for a new transaction.
// It creates a new client.Txn and initializes it using the session defaults.
// txnState.State will be set to Open.
func (ts *txnState) resetForNewSQLTxn(e *Executor, s *Session) {
if ts.sp != nil {
panic(fmt.Sprintf("txnState.reset() called on ts with active span. How come "+
"finishSQLTxn() wasn't called previously? ts: %+v", ts))
}
// Reset state vars to defaults.
ts.retrying = false
ts.retryIntent = false
ts.autoRetry = false
ts.commitSeen = false
// Discard previously collected spans. We start collecting anew on
// every fresh SQL txn.
ts.CollectedSpans = nil
// Create a context for this transaction. It will include a
// root span that will contain everything executed as part of the
// upcoming SQL txn, including (automatic or user-directed) retries.
// The span is closed by finishSQLTxn().
// TODO(andrei): figure out how to close these spans on server shutdown?
ctx := s.context
var sp opentracing.Span
if traceSQL {
var err error
sp, err = tracing.JoinOrNewSnowball("coordinator", nil, func(sp basictracer.RawSpan) {
ts.CollectedSpans = append(ts.CollectedSpans, sp)
})
if err != nil {
log.Warningf(ctx, "unable to create snowball tracer: %s", err)
return
}
} else if traceSQLFor7881 {
var err error
sp, _, err = tracing.NewTracerAndSpanFor7881(func(sp basictracer.RawSpan) {
ts.CollectedSpans = append(ts.CollectedSpans, sp)
})
if err != nil {
log.Fatalf(ctx, "couldn't create a tracer for debugging #7881: %s", err)
}
} else {
if parentSp := opentracing.SpanFromContext(ctx); parentSp != nil {
// Create a child span for this SQL txn.
tracer := parentSp.Tracer()
sp = tracer.StartSpan("sql txn", opentracing.ChildOf(parentSp.Context()))
} else {
// Create a root span for this SQL txn.
tracer := e.cfg.AmbientCtx.Tracer
sp = tracer.StartSpan("sql txn")
}
}
// Put the new span in the context.
ts.sp = sp
ctx = opentracing.ContextWithSpan(ctx, sp)
ts.Ctx = ctx
ts.mon.Start(ctx, &s.mon, mon.BoundAccount{})
ts.txn = client.NewTxn(ts.Ctx, *e.cfg.DB)
ts.txn.Proto.Isolation = s.DefaultIsolationLevel
ts.State = Open
// Discard the old schemaChangers, if any.
ts.schemaChangers = schemaChangerCollection{}
}
// Trace looks for an opentracing.Trace in the context and logs the given
// message to it on success.
func Trace(ctx context.Context, msg string) {
sp := opentracing.SpanFromContext(ctx)
if sp != nil {
sp.LogEvent(msg)
}
}