X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?p=controller.git;a=blobdiff_plain;f=opendaylight%2Fmd-sal%2Fsal-distributed-datastore%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fcluster%2Fdatabroker%2Factors%2Fdds%2FAbstractProxyTransaction.java;h=07b89e09230949da6c4849b3fb5dc03d4c3c36d8;hp=e6313d3cfd68f052b9e51582ac6e280983b92b99;hb=18ddbfdc55a1faddf7aeb2df6b25481d34c820ab;hpb=b66d5a3c59525a1c7885c3d653d9657a99f4103d diff --git a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/AbstractProxyTransaction.java b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/AbstractProxyTransaction.java index e6313d3cfd..07b89e0923 100644 --- a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/AbstractProxyTransaction.java +++ b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/AbstractProxyTransaction.java @@ -8,10 +8,12 @@ package org.opendaylight.controller.cluster.databroker.actors.dds; import akka.actor.ActorRef; +import com.google.common.base.MoreObjects; import com.google.common.base.Optional; import com.google.common.base.Preconditions; import com.google.common.base.Throwables; import com.google.common.base.Verify; +import com.google.common.collect.Iterables; import com.google.common.util.concurrent.CheckedFuture; import com.google.common.util.concurrent.ListenableFuture; import com.google.common.util.concurrent.SettableFuture; @@ -27,6 +29,9 @@ import javax.annotation.Nullable; import javax.annotation.concurrent.GuardedBy; import javax.annotation.concurrent.NotThreadSafe; import org.opendaylight.controller.cluster.access.client.ConnectionEntry; +import org.opendaylight.controller.cluster.access.commands.AbstractLocalTransactionRequest; +import org.opendaylight.controller.cluster.access.commands.ClosedTransactionException; +import org.opendaylight.controller.cluster.access.commands.IncrementTransactionSequenceRequest; import org.opendaylight.controller.cluster.access.commands.TransactionAbortRequest; import org.opendaylight.controller.cluster.access.commands.TransactionAbortSuccess; import org.opendaylight.controller.cluster.access.commands.TransactionCanCommitSuccess; @@ -34,6 +39,7 @@ import org.opendaylight.controller.cluster.access.commands.TransactionCommitSucc import org.opendaylight.controller.cluster.access.commands.TransactionDoCommitRequest; import org.opendaylight.controller.cluster.access.commands.TransactionPreCommitRequest; import org.opendaylight.controller.cluster.access.commands.TransactionPreCommitSuccess; +import org.opendaylight.controller.cluster.access.commands.TransactionPurgeRequest; import org.opendaylight.controller.cluster.access.commands.TransactionRequest; import org.opendaylight.controller.cluster.access.concepts.Request; import org.opendaylight.controller.cluster.access.concepts.RequestFailure; @@ -66,18 +72,30 @@ abstract class AbstractProxyTransaction implements Identifiable + * When a user operation encounters this state, it synchronizes on the it and wait until reconnection completes, + * at which point the request is routed to the successor transaction. This is a relatively heavy-weight solution + * to the problem of state transfer, but the user will observe it only if the race condition is hit. + */ + private static class SuccessorState extends State { private final CountDownLatch latch = new CountDownLatch(1); private AbstractProxyTransaction successor; private State prevState; + // SUCCESSOR + DONE + private boolean done; + SuccessorState() { - super("successor"); + super("SUCCESSOR"); } // Synchronize with succession process and return the successor @@ -117,12 +148,15 @@ abstract class AbstractProxyTransaction implements Identifiable STATE_UPDATER = AtomicReferenceFieldUpdater.newUpdater(AbstractProxyTransaction.class, State.class, "state"); - private static final State OPEN = new State("open"); - private static final State SEALED = new State("sealed"); - private static final State FLUSHED = new State("flushed"); + + /** + * Transaction has been open and is being actively worked on. + */ + private static final State OPEN = new State("OPEN"); + + /** + * Transaction has been sealed by the user, but it has not completed flushing to the backed, yet. This is + * a transition state, as we are waiting for the user to initiate commit procedures. + * + *

+ * Since the reconnect mechanics relies on state replay for transactions, this state needs to be flushed into the + * queue to re-create state in successor transaction (which may be based on different messages as locality may have + * changed). Hence the transition to {@link #FLUSHED} state needs to be handled in a thread-safe manner. + */ + private static final State SEALED = new State("SEALED"); + + /** + * Transaction state has been flushed into the queue, i.e. it is visible by the successor and potentially + * the backend. At this point the transaction does not hold any state besides successful requests, all other state + * is held either in the connection's queue or the successor object. + * + *

+ * Transition to this state indicates we have all input from the user we need to initiate the correct commit + * protocol. + */ + private static final State FLUSHED = new State("FLUSHED"); + + /** + * Transaction state has been completely resolved, we have received confirmation of the transaction fate from + * the backend. The only remaining task left to do is finishing up the state cleanup, which is done via purge + * request. We need to hang on to the transaction until that is done, as we have to make sure backend completes + * purging its state -- otherwise we could have a leak on the backend. + */ + private static final State DONE = new State("DONE"); // Touched from client actor thread only private final Deque successfulRequests = new ArrayDeque<>(); @@ -176,18 +251,32 @@ abstract class AbstractProxyTransaction implements Identifiable { + command.run(); + return behavior; + }); } final ActorRef localActor() { return parent.localActor(); } - private void incrementSequence(final long delta) { + final void incrementSequence(final long delta) { sequence += delta; LOG.debug("Transaction {} incremented sequence to {}", this, sequence); } @@ -226,42 +315,79 @@ abstract class AbstractProxyTransaction implements Identifiable request, final Consumer> callback, + final long enqueuedTicks) { + LOG.debug("Transaction proxy {} enqueing request {} callback {}", this, request, callback); + parent.enqueueRequest(request, callback, enqueuedTicks); + } + final void sendRequest(final TransactionRequest request, final Consumer> callback) { LOG.debug("Transaction proxy {} sending request {} callback {}", this, request, callback); parent.sendRequest(request, callback); } /** - * Seal this transaction before it is either committed or aborted. + * Seal this transaction before it is either committed or aborted. This method should only be invoked from + * application thread. */ final void seal() { // Transition user-visible state first - final boolean success = SEALED_UPDATER.compareAndSet(this, 0, 1); + final boolean success = markSealed(); Preconditions.checkState(success, "Proxy %s was already sealed", getIdentifier()); - internalSeal(); + + if (!sealAndSend(Optional.absent())) { + sealSuccessor(); + } + } + + /** + * Internal seal propagation method, invoked when we have raced with reconnection thread. Note that there may have + * been multiple reconnects, so we have to make sure the action is propagate through all intermediate instances. + */ + private void sealSuccessor() { + // Slow path: wait for the successor to complete + final AbstractProxyTransaction successor = awaitSuccessor(); + + // At this point the successor has completed transition and is possibly visible by the user thread, which is + // still stuck here. The successor has not seen final part of our state, nor the fact it is sealed. + // Propagate state and seal the successor. + flushState(successor); + successor.predecessorSealed(); } - final void ensureSealed() { - if (SEALED_UPDATER.compareAndSet(this, 0, 1)) { - internalSeal(); + private void predecessorSealed() { + if (markSealed() && !sealAndSend(Optional.absent())) { + sealSuccessor(); } } - private void internalSeal() { - doSeal(); + void sealOnly() { parent.onTransactionSealed(this); + final boolean success = STATE_UPDATER.compareAndSet(this, OPEN, SEALED); + Verify.verify(success, "Attempted to replay seal on {}", this); + } - // Now deal with state transfer, which can occur via successor or a follow-up canCommit() or directCommit(). - if (!STATE_UPDATER.compareAndSet(this, OPEN, SEALED)) { - // Slow path: wait for the successor to complete - final AbstractProxyTransaction successor = awaitSuccessor(); + /** + * Seal this transaction and potentially send it out towards the backend. If this method reports false, the caller + * needs to deal with propagating the seal operation towards the successor. + * + * @param enqueuedTicks Enqueue ticks when this is invoked from replay path. + * @return True if seal operation was successful, false if this proxy has a successor. + */ + boolean sealAndSend(final Optional enqueuedTicks) { + parent.onTransactionSealed(this); - // At this point the successor has completed transition and is possibly visible by the user thread, which is - // still stuck here. The successor has not seen final part of our state, nor the fact it is sealed. - // Propagate state and seal the successor. - flushState(successor); - successor.ensureSealed(); - } + // Transition internal state to sealed and detect presence of a successor + return STATE_UPDATER.compareAndSet(this, OPEN, SEALED); + } + + /** + * Mark this proxy as having been sealed. + * + * @return True if this call has transitioned to sealed state. + */ + final boolean markSealed() { + return SEALED_UPDATER.compareAndSet(this, 0, 1); } private void checkNotSealed() { @@ -288,12 +414,12 @@ abstract class AbstractProxyTransaction implements Identifiable response) { final Object last = successfulRequests.peekLast(); if (last instanceof IncrementSequence) { ((IncrementSequence) last).incrementDelta(); } else { - successfulRequests.addLast(new IncrementSequence()); + successfulRequests.addLast(new IncrementSequence(response.getSequence())); } } @@ -303,29 +429,51 @@ abstract class AbstractProxyTransaction implements Identifiable { + LOG.debug("Transaction {} abort completed with {}", getIdentifier(), resp); + enqueuePurge(); + }); } final void abort(final VotingFuture ret) { checkSealed(); - sendAbort(t -> { + sendDoAbort(t -> { if (t instanceof TransactionAbortSuccess) { ret.voteYes(); } else if (t instanceof RequestFailure) { - ret.voteNo(((RequestFailure) t).getCause()); + ret.voteNo(((RequestFailure) t).getCause().unwrap()); } else { ret.voteNo(new IllegalStateException("Unhandled response " + t.getClass())); } // This is a terminal request, hence we do not need to record it LOG.debug("Transaction {} abort completed", this); - parent.completeTransaction(this); + enqueuePurge(); }); } - final void sendAbort(final Consumer> callback) { + final void enqueueAbort(final Consumer> callback, final long enqueuedTicks) { + checkNotSealed(); + parent.abortTransaction(this); + + enqueueRequest(abortRequest(), resp -> { + LOG.debug("Transaction {} abort completed with {}", getIdentifier(), resp); + // Purge will be sent by the predecessor's callback + if (callback != null) { + callback.accept(resp); + } + }, enqueuedTicks); + } + + final void enqueueDoAbort(final Consumer> callback, final long enqueuedTicks) { + enqueueRequest(new TransactionAbortRequest(getIdentifier(), nextSequence(), localActor()), callback, + enqueuedTicks); + } + + final void sendDoAbort(final Consumer> callback) { sendRequest(new TransactionAbortRequest(getIdentifier(), nextSequence(), localActor()), callback); } @@ -347,14 +495,21 @@ abstract class AbstractProxyTransaction implements Identifiable) t).getCause()); + final Throwable cause = ((RequestFailure) t).getCause().unwrap(); + if (cause instanceof ClosedTransactionException) { + // This is okay, as it indicates the transaction has been completed. It can happen + // when we lose connectivity with the backend after it has received the request. + ret.set(Boolean.TRUE); + } else { + ret.setException(cause); + } } else { ret.setException(new IllegalStateException("Unhandled response " + t.getClass())); } // This is a terminal request, hence we do not need to record it LOG.debug("Transaction {} directCommit completed", this); - parent.completeTransaction(this); + enqueuePurge(); }); return ret; @@ -378,7 +533,7 @@ abstract class AbstractProxyTransaction implements Identifiable) t).getCause()); + ret.voteNo(((RequestFailure) t).getCause().unwrap()); } else { ret.voteNo(new IllegalStateException("Unhandled response " + t.getClass())); } @@ -409,16 +564,31 @@ abstract class AbstractProxyTransaction implements Identifiable) t).getCause()); + ret.voteNo(((RequestFailure) t).getCause().unwrap()); } else { ret.voteNo(new IllegalStateException("Unhandled response " + t.getClass())); } - recordSuccessfulRequest(req); - LOG.debug("Transaction {} preCommit completed", this); + onPreCommitComplete(req); }); } + private void onPreCommitComplete(final TransactionRequest req) { + /* + * The backend has agreed that the transaction has entered PRE_COMMIT phase, meaning it will be committed + * to storage after the timeout completes. + * + * All state has been replicated to the backend, hence we do not need to keep it around. Retain only + * the precommit request, so we know which request to use for resync. + */ + LOG.debug("Transaction {} preCommit completed, clearing successfulRequests", this); + successfulRequests.clear(); + + // TODO: this works, but can contain some useless state (like batched operations). Create an empty + // equivalent of this request and store that. + recordSuccessfulRequest(req); + } + final void doCommit(final VotingFuture ret) { checkReadWrite(); checkSealed(); @@ -427,16 +597,54 @@ abstract class AbstractProxyTransaction implements Identifiable) t).getCause()); + ret.voteNo(((RequestFailure) t).getCause().unwrap()); } else { ret.voteNo(new IllegalStateException("Unhandled response " + t.getClass())); } LOG.debug("Transaction {} doCommit completed", this); + + // Needed for ProxyHistory$Local data tree rebase points. parent.completeTransaction(this); + + enqueuePurge(); }); } + private void enqueuePurge() { + enqueuePurge(null); + } + + final void enqueuePurge(final Consumer> callback) { + // Purge request are dispatched internally, hence should not wait + enqueuePurge(callback, parent.currentTime()); + } + + final void enqueuePurge(final Consumer> callback, final long enqueuedTicks) { + LOG.debug("{}: initiating purge", this); + + final State prev = state; + if (prev instanceof SuccessorState) { + ((SuccessorState) prev).setDone(); + } else { + final boolean success = STATE_UPDATER.compareAndSet(this, prev, DONE); + if (!success) { + LOG.warn("{}: moved from state {} while we were purging it", this, prev); + } + } + + successfulRequests.clear(); + + enqueueRequest(new TransactionPurgeRequest(getIdentifier(), nextSequence(), localActor()), resp -> { + LOG.debug("{}: purge completed", this); + parent.purgeTransaction(this); + + if (callback != null) { + callback.accept(resp); + } + }, enqueuedTicks); + } + // Called with the connection unlocked final synchronized void startReconnect() { // At this point canCommit/directCommit are blocked, we assert a new successor state, retrieving the previous @@ -455,23 +663,40 @@ abstract class AbstractProxyTransaction implements Identifiable enqueuedEntries) { + final void replayMessages(final ProxyHistory successorHistory, final Iterable enqueuedEntries) { final SuccessorState local = getSuccessorState(); + final State prevState = local.getPrevState(); + + final AbstractProxyTransaction successor = successorHistory.createTransactionProxy(getIdentifier(), + isSnapshotOnly(), local.isDone()); + LOG.debug("{} created successor {}", this, successor); local.setSuccessor(successor); // Replay successful requests first - for (Object obj : successfulRequests) { - if (obj instanceof TransactionRequest) { - LOG.debug("Forwarding successful request {} to successor {}", obj, successor); - successor.handleForwardedRemoteRequest((TransactionRequest) obj, null); - } else { - Verify.verify(obj instanceof IncrementSequence); - successor.incrementSequence(((IncrementSequence) obj).getDelta()); + if (!successfulRequests.isEmpty()) { + // We need to find a good timestamp to use for successful requests, as we do not want to time them out + // nor create timing inconsistencies in the queue -- requests are expected to be ordered by their enqueue + // time. We will pick the time of the first entry available. If there is none, we will just use current + // time, as all other requests will get enqueued afterwards. + final ConnectionEntry firstInQueue = Iterables.getFirst(enqueuedEntries, null); + final long now = firstInQueue != null ? firstInQueue.getEnqueuedTicks() : parent.currentTime(); + + for (Object obj : successfulRequests) { + if (obj instanceof TransactionRequest) { + LOG.debug("Forwarding successful request {} to successor {}", obj, successor); + successor.doReplayRequest((TransactionRequest) obj, resp -> { }, now); + } else { + Verify.verify(obj instanceof IncrementSequence); + final IncrementSequence increment = (IncrementSequence) obj; + successor.doReplayRequest(new IncrementTransactionSequenceRequest(getIdentifier(), + increment.getSequence(), localActor(), isSnapshotOnly(), increment.getDelta()), resp -> { }, + now); + LOG.debug("Incrementing sequence {} to successor {}", obj, successor); + } } + LOG.debug("{} replayed {} successful requests", getIdentifier(), successfulRequests.size()); + successfulRequests.clear(); } - LOG.debug("{} replayed {} successful requests", getIdentifier(), successfulRequests.size()); - successfulRequests.clear(); // Now replay whatever is in the connection final Iterator it = enqueuedEntries.iterator(); @@ -481,8 +706,8 @@ abstract class AbstractProxyTransaction implements Identifiable) req, e.getCallback()); + LOG.debug("Replaying queued request {} to successor {}", req, successor); + successor.doReplayRequest((TransactionRequest) req, e.getCallback(), e.getEnqueuedTicks()); it.remove(); } } @@ -492,11 +717,32 @@ abstract class AbstractProxyTransaction implements Identifiable + * Note: this method is invoked by the predecessor on the successor. + * + * @param request Request which needs to be forwarded + * @param callback Callback to be invoked once the request completes + * @param enqueuedTicks ticker-based time stamp when the request was enqueued + */ + private void doReplayRequest(final TransactionRequest request, final Consumer> callback, + final long enqueuedTicks) { + if (request instanceof AbstractLocalTransactionRequest) { + handleReplayedLocalRequest((AbstractLocalTransactionRequest) request, callback, enqueuedTicks); + } else { + handleReplayedRemoteRequest(request, callback, enqueuedTicks); } } @@ -516,9 +762,12 @@ abstract class AbstractProxyTransaction implements Identifiable request, final Consumer> callback) { - final AbstractProxyTransaction successor = getSuccessorState().getSuccessor(); + final void forwardRequest(final TransactionRequest request, final Consumer> callback) { + forwardToSuccessor(getSuccessorState().getSuccessor(), request, callback); + } + final void forwardToSuccessor(final AbstractProxyTransaction successor, final TransactionRequest request, + final Consumer> callback) { if (successor instanceof LocalProxyTransaction) { forwardToLocal((LocalProxyTransaction)successor, request, callback); } else if (successor instanceof RemoteProxyTransaction) { @@ -528,6 +777,11 @@ abstract class AbstractProxyTransaction implements Identifiable request, final Consumer> callback, + final long enqueuedTicks) { + getSuccessorState().getSuccessor().doReplayRequest(request, callback, enqueuedTicks); + } + abstract boolean isSnapshotOnly(); abstract void doDelete(YangInstanceIdentifier path); @@ -540,38 +794,53 @@ abstract class AbstractProxyTransaction implements Identifiable>, ReadFailedException> doRead(YangInstanceIdentifier path); - abstract void doSeal(); - - abstract void doAbort(); - @GuardedBy("this") abstract void flushState(AbstractProxyTransaction successor); + abstract TransactionRequest abortRequest(); + abstract TransactionRequest commitRequest(boolean coordinated); /** - * Invoked from {@link RemoteProxyTransaction} when it replays its successful requests to its successor. There is - * no equivalent of this call from {@link LocalProxyTransaction} because it does not send a request until all - * operations are packaged in the message. + * Replay a request originating in this proxy to a successor remote proxy. + */ + abstract void forwardToRemote(RemoteProxyTransaction successor, TransactionRequest request, + Consumer> callback); + + /** + * Replay a request originating in this proxy to a successor local proxy. + */ + abstract void forwardToLocal(LocalProxyTransaction successor, TransactionRequest request, + Consumer> callback); + + /** + * Invoked from {@link LocalProxyTransaction} when it replays its successful requests to its successor. * *

* Note: this method is invoked by the predecessor on the successor. * * @param request Request which needs to be forwarded * @param callback Callback to be invoked once the request completes + * @param enqueuedTicks Time stamp to use for enqueue time */ - abstract void handleForwardedRemoteRequest(TransactionRequest request, - @Nullable Consumer> callback); + abstract void handleReplayedLocalRequest(AbstractLocalTransactionRequest request, + @Nullable Consumer> callback, long enqueuedTicks); /** - * Replay a request originating in this proxy to a successor remote proxy. + * Invoked from {@link RemoteProxyTransaction} when it replays its successful requests to its successor. + * + *

+ * Note: this method is invoked by the predecessor on the successor. + * + * @param request Request which needs to be forwarded + * @param callback Callback to be invoked once the request completes + * @param enqueuedTicks Time stamp to use for enqueue time */ - abstract void forwardToRemote(RemoteProxyTransaction successor, TransactionRequest request, - Consumer> callback); + abstract void handleReplayedRemoteRequest(TransactionRequest request, + @Nullable Consumer> callback, long enqueuedTicks); - /** - * Replay a request originating in this proxy to a successor local proxy. - */ - abstract void forwardToLocal(LocalProxyTransaction successor, TransactionRequest request, - Consumer> callback); + @Override + public final String toString() { + return MoreObjects.toStringHelper(this).add("identifier", getIdentifier()).add("state", state).toString(); + } }