com.apple.foundationdb.record.provider.foundationdb

Class OnlineIndexer

java.lang.Object

com.apple.foundationdb.record.provider.foundationdb.OnlineIndexer

All Implemented Interfaces:

AutoCloseable

@API(value=UNSTABLE)
public class OnlineIndexer
extends Object
implements AutoCloseable

Builds an index online, i.e., concurrently with other database operations. In order to minimize the impact that these operations have with other operations, this attempts to minimize the priorities of its transactions. Additionally, it attempts to limit the amount of work it will done in a fashion that will decrease as the number of failures for a given build attempt increases.

As ranges of elements are rebuilt, the fact that the range has rebuilt is added to a RangeSet associated with the index being built. This RangeSet is used to (a) coordinate work between different builders that might be running on different machines to ensure that the same work isn't duplicated and to (b) make sure that non-idempotent indexes (like COUNT or SUM_LONG) don't update themselves (or fail to update themselves) incorrectly.

Unlike many other features in the Record Layer core, this has a retry loop.

Build an index immediately in the current transaction:

 try (OnlineIndexer indexBuilder = OnlineIndexer.forRecordStoreAndIndex(recordStore, "newIndex")) {
     indexBuilder.rebuildIndex(recordStore);
 }
 

Build an index synchronously in the multiple transactions:

 try (OnlineIndexer indexBuilder = OnlineIndexer.forRecordStoreAndIndex(recordStore, "newIndex")) {
     indexBuilder.buildIndex();
 }
 

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	OnlineIndexer.Builder Builder for OnlineIndexer.
static class	OnlineIndexer.RecordBuiltRangeException This Exception can be thrown in the case that one calls one of the methods that explicitly state that they are building an unbuilt range, i.e., a range of keys that contains no keys which have yet been processed by the OnlineIndexer during an index build.

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_LIMIT Default number of records to attempt to run in a single transaction.
static int	DEFAULT_MAX_RETRIES Default number of times to retry a single range rebuild.
static int	DEFAULT_PROGRESS_LOG_INTERVAL Default interval to be logging successful progress in millis when building across transactions.
static int	DEFAULT_RECORDS_PER_SECOND Default limit to the number of records to attempt in a single second.
static int	DO_NOT_RE_INCREASE_LIMIT If OnlineIndexer.Builder.getIncreaseLimitAfter() is this value, the limit will not go back up, no matter how many successes there are.
static int	UNLIMITED Constant indicating that there should be no limit to some usually limited operation.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	OnlineIndexer(FDBDatabaseRunner runner, FDBRecordStore.Builder recordStoreBuilder, Index index, Collection<RecordType> recordTypes, int maxLimit, int maxRetries, int recordsPerSecond, long progressLogIntervalMillis, int increaseLimitAfter)

Method Summary

Modifier and Type	Method and Description
<T> T	asyncToSync(CompletableFuture<T> buildIndexFuture) Wait for asynchronous index build to complete.
CompletableFuture<TupleRange>	buildEndpoints() Builds (with a retry loop) the endpoints of an index.
CompletableFuture<TupleRange>	buildEndpoints(FDBRecordStore store) Builds (transactionally) the endpoints of an index.
void	buildIndex() Builds an index across multiple transactions.
void	buildIndex(boolean markReadable) Builds an index across multiple transactions.
CompletableFuture<Void>	buildIndexAsync() Builds an index across multiple transactions.
CompletableFuture<Void>	buildIndexAsync(boolean markReadable) Builds an index across multiple transactions.
CompletableFuture<Void>	buildRange(FDBRecordStore store, Key.Evaluated start, Key.Evaluated end) Builds (transactionally) the index by adding records with primary keys within the given range.
CompletableFuture<Void>	buildRange(Key.Evaluated start, Key.Evaluated end) Builds (with a retry loop) the index by adding records with primary keys within the given range.
CompletableFuture<Key.Evaluated>	buildUnbuiltRange(FDBRecordStore store, Key.Evaluated start, Key.Evaluated end) Builds (transactionally) the index by adding records with primary keys within the given range.
void	close()
static OnlineIndexer	forRecordStoreAndIndex(FDBRecordStore recordStore, String index) Create an online indexer for the given record store and index.
int	getLimit() Get the current number of records to process in one transaction.
CompletableFuture<Boolean>	markReadable() Mark the index as readable.
CompletableFuture<Boolean>	markReadableIfBuilt() Mark the index as readable if it is built.
static OnlineIndexer.Builder	newBuilder() Create an online indexer builder.
void	rebuildIndex(FDBRecordStore store) Transactionally rebuild an entire index.
CompletableFuture<Void>	rebuildIndexAsync(FDBRecordStore store) Transactionally rebuild an entire index.
List<org.apache.commons.lang3.tuple.Pair<Tuple,Tuple>>	splitIndexBuildRange(int minSplit, int maxSplit) Split the index build range to support building an index across multiple transactions in parallel if needed.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_LIMIT

public static final int DEFAULT_LIMIT

Default number of records to attempt to run in a single transaction.

See Also:

Constant Field Values

DEFAULT_RECORDS_PER_SECOND

public static final int DEFAULT_RECORDS_PER_SECOND

Default limit to the number of records to attempt in a single second.

See Also:

Constant Field Values

DEFAULT_MAX_RETRIES

public static final int DEFAULT_MAX_RETRIES

Default number of times to retry a single range rebuild.

See Also:

Constant Field Values

DEFAULT_PROGRESS_LOG_INTERVAL

public static final int DEFAULT_PROGRESS_LOG_INTERVAL

Default interval to be logging successful progress in millis when building across transactions. -1 means it will not log.

See Also:

Constant Field Values

UNLIMITED

public static final int UNLIMITED

Constant indicating that there should be no limit to some usually limited operation.

See Also:

Constant Field Values

DO_NOT_RE_INCREASE_LIMIT

public static final int DO_NOT_RE_INCREASE_LIMIT

If OnlineIndexer.Builder.getIncreaseLimitAfter() is this value, the limit will not go back up, no matter how many successes there are. This is the default value.

See Also:

Constant Field Values

Constructor Detail

OnlineIndexer

protected OnlineIndexer(@Nonnull
                        FDBDatabaseRunner runner,
                        @Nonnull
                        FDBRecordStore.Builder recordStoreBuilder,
                        @Nonnull
                        Index index,
                        @Nonnull
                        Collection<RecordType> recordTypes,
                        int maxLimit,
                        int maxRetries,
                        int recordsPerSecond,
                        long progressLogIntervalMillis,
                        int increaseLimitAfter)

Method Detail

getLimit

public int getLimit()

Get the current number of records to process in one transaction. This may go up or down while runAsync(Function) is running, if there are failures committing or repeated successes.

Returns:

the current number of records to process in one transaction

close

public void close()

Specified by:

close in interface AutoCloseable

buildRange

@Nonnull
public CompletableFuture<Void> buildRange(@Nonnull
                                                   FDBRecordStore store,
                                                   @Nullable
                                                   Key.Evaluated start,
                                                   @Nullable
                                                   Key.Evaluated end)

Builds (transactionally) the index by adding records with primary keys within the given range. This will look for gaps of keys within the given range that haven't yet been rebuilt and then rebuild only those ranges. As a result, if this method is called twice, the first time, it will build whatever needs to be built, and then the second time, it will notice that there are no ranges that need to be built, so it will do nothing. In this way, it is idempotent and thus safe to use in retry loops. This method will fail if there is too much work to be done in a single transaction. If one wants to handle building a range that does not fit in a single transaction, one should use the buildRange() function that takes an FDBDatabase as its first parameter.

Parameters:

store - the record store in which to rebuild the range

start - the (inclusive) beginning primary key of the range to build (or null to go to the end)

end - the (exclusive) end primary key of the range to build (or null to go to the end)

Returns:

a future that will be ready when the build has completed

buildRange

@Nonnull
public CompletableFuture<Void> buildRange(@Nullable
                                                   Key.Evaluated start,
                                                   @Nullable
                                                   Key.Evaluated end)

Builds (with a retry loop) the index by adding records with primary keys within the given range. This will look for gaps of keys within the given range that haven't yet been rebuilt and then rebuild only those ranges. It will also limit each transaction to the number of records specified by the limit parameter of this class's constructor. In the case that that limit is too high (i.e., it can't make any progress or errors out on a non-retriable error like transaction_too_large, this method will actually decrease the limit so that less work is attempted each transaction. It will also rate limit itself as to not make too many requests per second.

Parameters:

start - the (inclusive) beginning primary key of the range to build (or null to go from the beginning)

end - the (exclusive) end primary key of the range to build (or null to go to the end)

Returns:

a future that will be ready when the build has completed

buildUnbuiltRange

@Nonnull
public CompletableFuture<Key.Evaluated> buildUnbuiltRange(@Nonnull
                                                                   FDBRecordStore store,
                                                                   @Nullable
                                                                   Key.Evaluated start,
                                                                   @Nullable
                                                                   Key.Evaluated end)

Builds (transactionally) the index by adding records with primary keys within the given range. This requires that the range is initially "unbuilt", i.e., no records within the given range have yet been processed by the index build job. It is acceptable if there are records within that range that have already been added to the index because they were added to the store after the index was added in write-only mode but have not yet been processed by the index build job. Note that this function is not idempotent in that if the first time this function runs, if it fails with commit_unknown_result but the transaction actually succeeds, running this function again will result in a OnlineIndexer.RecordBuiltRangeException being thrown the second time. Retry loops used by the OnlineIndexer class that call this method handle this contingency. For the most part, this method should only be used by those who know what they are doing. It is included because it is less expensive to make this call if one already knows that the range will be unbuilt, but the caller must be ready to handle the circumstance that the range might be built the second time. Most users should use the buildRange() method with the same parameters in the case that they want to build a range of keys into the index. That method is idempotent, but it is slightly more costly as it firsts determines what ranges are have not yet been built before building them.

Parameters:

store - the record store in which to rebuild the range

start - the (inclusive) beginning primary key of the range to build (or null to start from the beginning)

end - the (exclusive) end primary key of the range to build (or null to go to the end)

Returns:

a future with the key of the first record not processed by this range rebuild

Throws:

OnlineIndexer.RecordBuiltRangeException - if the given range contains keys already processed by the index build

rebuildIndexAsync

@Nonnull
public CompletableFuture<Void> rebuildIndexAsync(@Nonnull
                                                          FDBRecordStore store)

Transactionally rebuild an entire index. This will (1) delete any data in the index that is already there and (2) rebuild the entire key range for the given index. It will attempt to do this within a single transaction, and it may fail if there are too many records, so this is only safe to do for small record stores. Many large use-cases should use the buildIndexAsync(boolean) method along with temporarily changing an index to write-only mode while the index is being rebuilt.

Parameters:

store - the record store in which to rebuild the index

Returns:

a future that will be ready when the build has completed

rebuildIndex

public void rebuildIndex(@Nonnull
                         FDBRecordStore store)

Transactionally rebuild an entire index. Synchronous version of rebuildIndexAsync(com.apple.foundationdb.record.provider.foundationdb.FDBRecordStore)

Parameters:

store - the record store in which to rebuild the index

See Also:

buildIndex(boolean)

buildEndpoints

@Nonnull
public CompletableFuture<TupleRange> buildEndpoints(@Nonnull
                                                             FDBRecordStore store)

Builds (transactionally) the endpoints of an index. What this means is that builds everything from the beginning of the key space to the first record and everything from the last record to the end of the key space. There won't be any records within these ranges (except for the last record of the record store), but it does mean that any records in the future that get added to these ranges will correctly update the index. This means, e.g., that if the workload primarily adds records to the record store after the current last record (because perhaps the primary key is based off of an atomic counter or the current time), running this method will be highly contentious, but once it completes, the rest of the index build should happen without any more conflicts. This will return a (possibly null) TupleRange that contains the primary keys of the first and last records within the record store. This can then be used to either build the range right away or to then divy-up the remaining ranges between multiple agents working in parallel if one desires.

Parameters:

store - the record store in which to rebuild the index

Returns:

a future that will contain the range of records in the interior of the record store

buildEndpoints

@Nonnull
public CompletableFuture<TupleRange> buildEndpoints()

Builds (with a retry loop) the endpoints of an index. See the buildEndpoints() method that takes an FDBRecordStore as its parameter for more details. This will retry on that function until it gets a non-exceptional result and return the results back.

Returns:

a future that will contain the range of records in the interior of the record store

buildIndexAsync

@Nonnull
public CompletableFuture<Void> buildIndexAsync(boolean markReadable)

Builds an index across multiple transactions. This will honor the rate-limiting parameters set in the constructor of this class. It will also retry any retriable errors that it encounters while it runs the build. At the end, it will mark the index readable in the store if specified.

Parameters:

markReadable - whether to mark the index as readable after building the index

Returns:

a future that will be ready when the build has completed

buildIndexAsync

@Nonnull
public CompletableFuture<Void> buildIndexAsync()

Builds an index across multiple transactions. This will honor the rate-limiting parameters set in the constructor of this class. It will also retry any retriable errors that it encounters while it runs the build.

Returns:

a future that will be ready when the build has completed

buildIndex

@Nonnull
public void buildIndex(boolean markReadable)

Builds an index across multiple transactions. Synchronous version of buildIndexAsync(boolean).

Parameters:

markReadable - whether to mark the index as readable after building the index

buildIndex

@Nonnull
public void buildIndex()

Builds an index across multiple transactions. Synchronous version of buildIndexAsync(boolean).

splitIndexBuildRange

@API(value=EXPERIMENTAL)
 @Nonnull
public List<org.apache.commons.lang3.tuple.Pair<Tuple,Tuple>> splitIndexBuildRange(int minSplit,
                                                                                                                      int maxSplit)

Split the index build range to support building an index across multiple transactions in parallel if needed.

It is blocking and should not be called in asynchronous contexts.

Parameters:

minSplit - not split if it cannot be split into at least minSplit ranges

maxSplit - the maximum number of splits generated

Returns:

a list of split primary key ranges (the low endpoint is inclusive and the high endpoint is exclusive)

markReadableIfBuilt

@API(value=EXPERIMENTAL)
 @Nonnull
public CompletableFuture<Boolean> markReadableIfBuilt()

Mark the index as readable if it is built.

Returns:

a future that will complete to true if the index is readable and false otherwise

markReadable

@API(value=EXPERIMENTAL)
 @Nonnull
public CompletableFuture<Boolean> markReadable()

Mark the index as readable.

Returns:

a future that will either complete exceptionally if the index can not be made readable or will contain true if the store was modified and false otherwise

asyncToSync

@API(value=INTERNAL)
public <T> T asyncToSync(@Nonnull
                                              CompletableFuture<T> buildIndexFuture)

Wait for asynchronous index build to complete.

This method was marked INTERNAL in a 2.5 release of the Record Layer, and it may be removed in version 2.7. Outside users of the Record Layer should use the asyncToSync methods of FDBRecordContext, FDBDatabase, or FDBDatabaseRunner instead. See Issue #473 for more details.

Type Parameters:

T - return type of function to run

Parameters:

buildIndexFuture - the result of buildIndexAsync(boolean)

Returns:

future that will contain the result of buildIndexFuture after successful run and commit

newBuilder

public static OnlineIndexer.Builder newBuilder()

Create an online indexer builder.

Returns:

a new online indexer builder

forRecordStoreAndIndex

public static OnlineIndexer forRecordStoreAndIndex(@Nonnull
                                                   FDBRecordStore recordStore,
                                                   @Nonnull
                                                   String index)

Create an online indexer for the given record store and index.

Parameters:

recordStore - record store in which to index

index - name of index to build

Returns:

a new online indexer