org.voltdb.dtxn.TransactionInitiator Maven / Gradle / Ivy
/* This file is part of VoltDB.
* Copyright (C) 2008-2018 VoltDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with VoltDB. If not, see A TransactionInitiator is the center of the distributed
* transaction system on each host. It is the only way to create new
* transactions and it is the only way to internally access the results
* of those transactions.
*
* TransactionInitiator is an abstract base class which is an
* interface to the pluggable transaction system. Different transaction
* systems with provide their own subclasses.
*
*/
public abstract class TransactionInitiator implements TransactionCreator {
/**
* Create a new transaction, which will result in one or more
* WorkUnit's being generated for worker partitions.
*
* Does not need to be synchronized as the scheduler will ensure
* that only one thread is ever accepting connections at a time.
*
* @param connectionId A unique integer identifying which TCP/IP connection
* spawned this transaction.
* @param invocation The data describing the work to be done.
* @param partition The partition for routing if it is a single part
* @param messageSize Size in bytes of the message that created this invocation
*/
@Override
public abstract boolean createTransaction(
long connectionId,
StoredProcedureInvocation invocation,
boolean isReadOnly,
boolean isSinglePartition,
boolean isEverySite,
int partition,
int messageSize,
long now);
/**
*
* Create a new transaction with a specified transaction ID, which will
* result in one or more WorkUnit's being generated for worker
* partitions.
*
*
*
* Does not need to be synchronized as the scheduler will ensure that only
* one thread is ever accepting connections at a time.
*
*
* @param connectionId
* A unique integer identifying which TCP/IP connection spawned
* this transaction.
* @param txnId
* The transaction ID to assign to this initiation
* @param invocation
* The data describing the work to be done.
* @param partition
* The partition for routing if it is a single part
* @param messageSize
* Size in bytes of the message that created this invocation
*/
@Override
public abstract boolean createTransaction(
long connectionId,
long txnId,
long timestamp,
StoredProcedureInvocation invocation,
boolean isReadOnly,
boolean isSinglePartition,
boolean isEverySite,
int partition,
int messageSize,
long now);
/**
* This method should be called every X ms or so, where X is probably
* about 5, but that's somewhat fungible. The goal is to let the initiator
* evaluate whether it's been too long since it's had contact with any
* execution sites, and to send a heartbeat message if needed.
*/
public abstract long tick();
/**
* @return The id of the most recently used transaction id.
* @deprecated
*/
@Deprecated
public abstract long getMostRecentTxnId();
/**
* Increase or reduce the amount of backpressure from this initiator.
*
* @param messageSize
*/
protected abstract void increaseBackpressure(int messageSize);
protected abstract void reduceBackpressure(int messageSize);
/**
* Called to notify an initiator that it is safe to send work
* to rejoined sites.
* @param executorSiteIds The ids of the sites that joined.
*/
public abstract void notifyExecutionSiteRejoin(ArrayList executorSiteIds);
public abstract Map getOutstandingTxnStats();
/**
* Removes client connection statistics when the connection dies
* @param connectionId
*/
public abstract void removeConnectionStats(long connectionId);
}