THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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Picture bellow illustrates steps of the algorithm on single node:
lastFinishedCutId
holds previous ConsistentCutId
, or null.SnapshotOperationRequest
that holds new ConsistentCutId
(goal is to notify every node in a cluster about running incremental snapshot). SnapshotOperationRequest#ConsistentCutId
by DiscoverySPI (by the DistributedProcess).ConsistentCutAwareMessage#ConsistentCutId
by CommunicationSPI (by transaction messages - Prepare, Finish).ConsistentCutId
, every node: ConsistentCut
!= null) or finished (lastFinishedCutId
== id) for this id, skip if it has.ConsistentCutAwareMessage#topVer
with local node order:ConsistentCut
future. ConsistentCut != null
wraps outgoing messages to ConsistentCutAwareMessage
. It contains info:ConsistentCutId
(to start ConsistentCut on remote node, if not yet).txCutId
equals to null then transaction starts committing Before
Consistent Cut started, otherwise After
.ConsistentCutAwareMessage
that makes transaction committed (FinishRequest for 2PC, PrepareResponse for 1PC) sets tx#txCutId = message#txCutId
.ConsistentCut
future.removedActiveTxs
(This collection doesn't remove transactions unlike IgniteTxManager#activeTx
does).ConsistentCutStartRecord
to WAL with the received ConsistentCutId
.IgniteTxManager#activeTx
. Set listeners on those tx#finishFuture
.tx#status == ACTIVE
. It's guaranteed that such transactions belongs After side.removedActiveTxs
(contains transactions that are might be cleaned from IgniteTxManager#activeTx
). Set listeners on those tx#finishFuture
.removedActiveTxs
to null. We don't care of txs concurrently added to removedActiveTxs
, they just don't land into "before" or "after" set and will be excluded from recovery.removedActiveTxs
if ConsistentCut
removedActiveTxs
is not After ConsistentCut future finish, DistributedProcess automatically notifies a node-!= null
and removedActiveTxs != null
:removedActiveTxs
right before it is removed from IgniteTxManager#activeTx
.tx#txCutId
equals to local, then put transaction into after, otherwise put into before.ConsistentCutFinishRecord
into WAL with the collections ( before, after ). ConsistentCut
future.ConsistentCutAwareMessage#topVer
with local node order:ConsistentCut
future.ConsistentCut != null
wraps outgoing messages to ConsistentCutAwareMessage
. It contains info:ConsistentCutId
(to start ConsistentCut on remote node, if not yet).Before
Consistent Cut started, otherwise After
.ConsistentCutAwareMessage
that make transaction committed (FinishRequest for 2PC, PrepareResponse for 1PC) Ignite set tx#txCutId = message#txCutId
before it starts handling the received message.ConsistentCut
future becomes null....
tx.finalizationStatus
== RECOVERY_FINISH)....
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Ignite transaction protocol includes multiple messages. But only some of them affects meaningful (relating to the algorithm) that change state of transactions (PREPARED, COMMITTED):
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Code Block | ||||
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class ConsistentCutAwareMessage {
/** Original transaction message. */
Message msg;
/** Consistent Cut ID. */
UUID cutId;
/** Consistent Cut ID after which transaction committed. */
@Nullable UUID txCutId;
/** Cluster topology version on which Consistent Cut started. */
long topVer;
} |
A new field added to IgniteInternalTx
Code Block | ||||
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class IgniteInternalTx {
/**
* @param ID of {@link ConsistentCut} AFTER which this transaction was committed, {@code null} if transaction
* committed BEFORE.
*/
public void cutId(@Nullable UUID id);
} |
Code Block | ||||
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// Class is responsible for managing all stuff related to Consistent Cut. It's an entrypoint for transaction threads to check running consistent cut.
class ConsistentCutManager extends GridCacheSharedManagerAdapter {
// Current Consistent Cut. All transactions threads wraps outgoing messages if this field is not null. */
volatile @Nullable ConsistentCut cut;
// Entrypoint for handling received new Consistent Cut ID.
void handleConsistentCutId(UUID id);
} |
Code Block | ||||
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class ConsistentCut extends GridFutureAdapter<WALPointer> {
Set<GridCacheVersion> beforeCut;
Set<GridCacheVersion> afterCut;
Set<IgniteInternalFuture<IgniteInternalTx>> removedActive;
} |