org.apache.tephra.distributed

Class TransactionServiceClient

java.lang.Object

org.apache.tephra.distributed.TransactionServiceClient

All Implemented Interfaces:

TransactionSystemClient

public class TransactionServiceClient
extends Object
implements TransactionSystemClient

A tx service client

Constructor Summary

Constructors

Constructor and Description
TransactionServiceClient(org.apache.hadoop.conf.Configuration config, ThriftClientProvider clientProvider) Create from a configuration.
TransactionServiceClient(org.apache.hadoop.conf.Configuration config, ThriftClientProvider clientProvider, String clientId) Create from a configuration.

Method Summary

Modifier and Type	Method and Description
void	abort(Transaction tx) Makes transaction visible.
boolean	canCommit(Transaction tx, Collection<byte[]> changeIds) Checks if transaction with the set of changes can be committed.
void	canCommitOrThrow(Transaction tx, Collection<byte[]> changeIds) Checks if transaction with the set of changes can be committed.
Transaction	checkpoint(Transaction tx) Performs a checkpoint operation on the current transaction, returning a new Transaction instance with the updated state.
boolean	commit(Transaction tx) Makes transaction visible.
void	commitOrThrow(Transaction tx) Makes transaction visible.
static void	doMain(boolean verbose, org.apache.hadoop.conf.Configuration conf)
int	getInvalidSize()
InputStream	getSnapshotInputStream() Retrieves the state of the transaction manager and send it as a stream.
boolean	invalidate(long tx) Makes transaction invalid.
static void	main(String[] args) Utility to be used for basic verification of transaction system availability and functioning
void	pruneNow() Trigger transaction pruning now.
void	resetState() Resets the state of the transaction manager.
Transaction	startLong() Starts new long transaction.
Transaction	startShort() Starts new short transaction.
Transaction	startShort(int timeout) Starts new short transaction.
String	status() Return the status of the transaction Manager
boolean	truncateInvalidTx(Set<Long> invalidTxIds) Removes the given transaction ids from the invalid list.
boolean	truncateInvalidTxBefore(long time) Removes all transaction ids started before the given time from invalid list.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TransactionServiceClient

public TransactionServiceClient(org.apache.hadoop.conf.Configuration config,
                                ThriftClientProvider clientProvider)

Create from a configuration. This will first attempt to find a zookeeper for service discovery. This constructor can be used if Guice dependency injection is not used. JVM name will be used for the client id.

Parameters:

config - a configuration containing the zookeeper properties

TransactionServiceClient

@Inject
public TransactionServiceClient(org.apache.hadoop.conf.Configuration config,
                                        ThriftClientProvider clientProvider,
                                        String clientId)

Create from a configuration. This will first attempt to find a zookeeper for service discovery. Otherwise it will look for the port in the config and use localhost.

Parameters:

config - a configuration containing the zookeeper properties

clientId - id of the client that identifies it when it starts a transaction

Method Detail

main

public static void main(String[] args)
                 throws Exception

Utility to be used for basic verification of transaction system availability and functioning

Parameters:

args - arguments list, accepts single option "-v" that makes it to print out more details about started tx

Throws:

Exception

doMain

public static void doMain(boolean verbose,
                          org.apache.hadoop.conf.Configuration conf)
                   throws Exception

Throws:

Exception

startLong

public Transaction startLong()

Description copied from interface: TransactionSystemClient

Starts new long transaction.

Specified by:

startLong in interface TransactionSystemClient

Returns:

instance of Transaction

startShort

public Transaction startShort()

Description copied from interface: TransactionSystemClient

Starts new short transaction.

Specified by:

startShort in interface TransactionSystemClient

Returns:

instance of Transaction

startShort

public Transaction startShort(int timeout)

Description copied from interface: TransactionSystemClient

Starts new short transaction.

Specified by:

startShort in interface TransactionSystemClient

Parameters:

timeout - the timeout for the transaction

Returns:

instance of Transaction

canCommit

public boolean canCommit(Transaction tx,
                         Collection<byte[]> changeIds)
                  throws TransactionNotInProgressException

Description copied from interface: TransactionSystemClient

Checks if transaction with the set of changes can be committed. E.g. it can check conflicts with other changes and refuse commit if there are conflicts. It is assumed that no other changes will be done in between this method call and TransactionSystemClient.commitOrThrow(Transaction) which will check conflicts again to avoid races.

Since we do conflict detection at commit time as well, this may seem redundant. The idea is to check for conflicts before we persist changes to avoid rollback in case of conflicts as much as possible. NOTE: in some situations we may want to skip this step to save on RPC with a risk of many rollback ops. So by default we take safe path.

Specified by:

canCommit in interface TransactionSystemClient

Parameters:

tx - transaction to verify

changeIds - ids of changes made by transaction

Returns:

true if transaction can be committed otherwise false

Throws:

TransactionNotInProgressException - if the transaction is not in progress; most likely it has timed out.

canCommitOrThrow

public void canCommitOrThrow(Transaction tx,
                             Collection<byte[]> changeIds)
                      throws TransactionFailureException

Description copied from interface: TransactionSystemClient

Checks if transaction with the set of changes can be committed. E.g. it can check conflicts with other changes and refuse commit if there are conflicts. It is assumed that no other changes will be done in between this method call and TransactionSystemClient.commitOrThrow(Transaction) which will check conflicts again to avoid races.

Since we do conflict detection at commit time as well, this may seem redundant. The idea is to check for conflicts before we persist changes to avoid rollback in case of conflicts as much as possible. NOTE: in some situations we may want to skip this step to save on RPC with a risk of many rollback ops. So by default we take safe path.

Specified by:

canCommitOrThrow in interface TransactionSystemClient

Parameters:

tx - transaction to verify

changeIds - ids of changes made by transaction

Throws:

TransactionSizeException - if the size of the change set exceeds the allowed limit

TransactionConflictException - if the change set has a conflict with an overlapping transaction

TransactionNotInProgressException - if the transaction is not in progress; most likely it has timed out

TransactionFailureException

commit

public boolean commit(Transaction tx)
               throws TransactionNotInProgressException

Description copied from interface: TransactionSystemClient

Makes transaction visible. It will again check conflicts of changes submitted previously with TransactionSystemClient.canCommitOrThrow(Transaction, java.util.Collection)

Specified by:

commit in interface TransactionSystemClient

Parameters:

tx - transaction to make visible.

Returns:

true if transaction can be committed otherwise false

Throws:

TransactionNotInProgressException

commitOrThrow

public void commitOrThrow(Transaction tx)
                   throws TransactionFailureException

Description copied from interface: TransactionSystemClient

Makes transaction visible. It will again check conflicts of changes submitted previously with TransactionSystemClient.canCommitOrThrow(Transaction, java.util.Collection)

Specified by:

commitOrThrow in interface TransactionSystemClient

Parameters:

tx - transaction to make visible.

Throws:

TransactionConflictException - if the transaction has a conflict with an overlapping transaction

TransactionNotInProgressException - if the transaction is not in progress; most likely it has timed out

TransactionFailureException

abort

public void abort(Transaction tx)

Description copied from interface: TransactionSystemClient

Makes transaction visible. You should call it only when all changes of this tx are undone. NOTE: it will not throw TransactionNotInProgressException if transaction has timed out.

Specified by:

abort in interface TransactionSystemClient

Parameters:

tx - transaction to make visible.

invalidate

public boolean invalidate(long tx)

Description copied from interface: TransactionSystemClient

Makes transaction invalid. You should call it if not all changes of this tx could be undone. NOTE: it will not throw TransactionNotInProgressException if transaction has timed out.

Specified by:

invalidate in interface TransactionSystemClient

Parameters:

tx - transaction id to invalidate.

Returns:

true if transaction has been successfully invalidated

checkpoint

public Transaction checkpoint(Transaction tx)
                       throws TransactionNotInProgressException

Description copied from interface: TransactionSystemClient

Performs a checkpoint operation on the current transaction, returning a new Transaction instance with the updated state. A checkpoint operation assigns a new write pointer for the current transaction.

Specified by:

checkpoint in interface TransactionSystemClient

Parameters:

tx - the current transaction to checkpoint

Returns:

an updated transaction instance with the new write pointer

Throws:

TransactionNotInProgressException

getSnapshotInputStream

public InputStream getSnapshotInputStream()
                                   throws TransactionCouldNotTakeSnapshotException

Description copied from interface: TransactionSystemClient

Retrieves the state of the transaction manager and send it as a stream. The snapshot will not be persisted.

Specified by:

getSnapshotInputStream in interface TransactionSystemClient

Returns:

an input stream containing an encoded snapshot of the transaction manager

Throws:

TransactionCouldNotTakeSnapshotException

status

public String status()

Description copied from interface: TransactionSystemClient

Return the status of the transaction Manager

Specified by:

status in interface TransactionSystemClient

Returns:

a String which denotes the status of txManager

resetState

public void resetState()

Description copied from interface: TransactionSystemClient

Resets the state of the transaction manager.

Specified by:

resetState in interface TransactionSystemClient

truncateInvalidTx

public boolean truncateInvalidTx(Set<Long> invalidTxIds)

Description copied from interface: TransactionSystemClient

Removes the given transaction ids from the invalid list.

Specified by:

truncateInvalidTx in interface TransactionSystemClient

Parameters:

invalidTxIds - transaction ids

Returns:

true if invalid list got changed, false otherwise

truncateInvalidTxBefore

public boolean truncateInvalidTxBefore(long time)
                                throws InvalidTruncateTimeException

Description copied from interface: TransactionSystemClient

Removes all transaction ids started before the given time from invalid list.

Specified by:

truncateInvalidTxBefore in interface TransactionSystemClient

Parameters:

time - time in milliseconds

Returns:

true if invalid list got changed, false otherwise

Throws:

InvalidTruncateTimeException - if there are any in-progress transactions started before given time

getInvalidSize

public int getInvalidSize()

Specified by:

getInvalidSize in interface TransactionSystemClient

Returns:

the size of invalid list

pruneNow

public void pruneNow()

Description copied from interface: TransactionSystemClient

Trigger transaction pruning now.

Specified by:

pruneNow in interface TransactionSystemClient