org.rocksdb.DBOptionsInterface Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of rocksdbjni Show documentation
Show all versions of rocksdbjni Show documentation
RocksDB fat jar that contains .so files for linux32 and linux64 (glibc and musl-libc), jnilib files
for Mac OSX, and a .dll for Windows x64.
The newest version!
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
package org.rocksdb;
import java.util.Collection;
import java.util.List;
public interface DBOptionsInterface> {
/**
* Use this if your DB is very small (like under 1GB) and you don't want to
* spend lots of memory for memtables.
*
* @return the instance of the current object.
*/
T optimizeForSmallDb();
/**
* Use the specified object to interact with the environment,
* e.g. to read/write files, schedule background work, etc.
* Default: {@link Env#getDefault()}
*
* @param env {@link Env} instance.
* @return the instance of the current Options.
*/
T setEnv(final Env env);
/**
* Returns the set RocksEnv instance.
*
* @return {@link RocksEnv} instance set in the options.
*/
Env getEnv();
/**
* By default, RocksDB uses only one background thread for flush and
* compaction. Calling this function will set it up such that total of
* `total_threads` is used.
*
* You almost definitely want to call this function if your system is
* bottlenecked by RocksDB.
*
* @param totalThreads The total number of threads to be used by RocksDB.
* A good value is the number of cores.
*
* @return the instance of the current Options
*/
T setIncreaseParallelism(int totalThreads);
/**
* If this value is set to true, then the database will be created
* if it is missing during {@code RocksDB.open()}.
* Default: false
*
* @param flag a flag indicating whether to create a database the
* specified database in {@link RocksDB#open(org.rocksdb.Options, String)} operation
* is missing.
* @return the instance of the current Options
* @see RocksDB#open(org.rocksdb.Options, String)
*/
T setCreateIfMissing(boolean flag);
/**
* Return true if the create_if_missing flag is set to true.
* If true, the database will be created if it is missing.
*
* @return true if the createIfMissing option is set to true.
* @see #setCreateIfMissing(boolean)
*/
boolean createIfMissing();
/**
* If true, missing column families will be automatically created
*
* Default: false
*
* @param flag a flag indicating if missing column families shall be
* created automatically.
* @return true if missing column families shall be created automatically
* on open.
*/
T setCreateMissingColumnFamilies(boolean flag);
/**
* Return true if the create_missing_column_families flag is set
* to true. If true column families be created if missing.
*
* @return true if the createMissingColumnFamilies is set to
* true.
* @see #setCreateMissingColumnFamilies(boolean)
*/
boolean createMissingColumnFamilies();
/**
* If true, an error will be thrown during RocksDB.open() if the
* database already exists.
* Default: false
*
* @param errorIfExists if true, an exception will be thrown
* during {@code RocksDB.open()} if the database already exists.
* @return the reference to the current option.
* @see RocksDB#open(org.rocksdb.Options, String)
*/
T setErrorIfExists(boolean errorIfExists);
/**
* If true, an error will be thrown during RocksDB.open() if the
* database already exists.
*
* @return if true, an error is raised when the specified database
* already exists before open.
*/
boolean errorIfExists();
/**
* If true, the implementation will do aggressive checking of the
* data it is processing and will stop early if it detects any
* errors. This may have unforeseen ramifications: for example, a
* corruption of one DB entry may cause a large number of entries to
* become unreadable or for the entire DB to become unopenable.
* If any of the writes to the database fails (Put, Delete, Merge, Write),
* the database will switch to read-only mode and fail all other
* Write operations.
* Default: true
*
* @param paranoidChecks a flag to indicate whether paranoid-check
* is on.
* @return the reference to the current option.
*/
T setParanoidChecks(boolean paranoidChecks);
/**
* If true, the implementation will do aggressive checking of the
* data it is processing and will stop early if it detects any
* errors. This may have unforeseen ramifications: for example, a
* corruption of one DB entry may cause a large number of entries to
* become unreadable or for the entire DB to become unopenable.
* If any of the writes to the database fails (Put, Delete, Merge, Write),
* the database will switch to read-only mode and fail all other
* Write operations.
*
* @return a boolean indicating whether paranoid-check is on.
*/
boolean paranoidChecks();
/**
* Use to control write rate of flush and compaction. Flush has higher
* priority than compaction. Rate limiting is disabled if nullptr.
* Default: nullptr
*
* @param rateLimiter {@link org.rocksdb.RateLimiter} instance.
* @return the instance of the current object.
*
* @since 3.10.0
*/
T setRateLimiter(RateLimiter rateLimiter);
/**
* Use to track SST files and control their file deletion rate.
*
* Features:
* - Throttle the deletion rate of the SST files.
* - Keep track the total size of all SST files.
* - Set a maximum allowed space limit for SST files that when reached
* the DB wont do any further flushes or compactions and will set the
* background error.
* - Can be shared between multiple dbs.
*
* Limitations:
* - Only track and throttle deletes of SST files in
* first db_path (db_name if db_paths is empty).
*
* @param sstFileManager The SST File Manager for the db.
* @return the instance of the current object.
*/
T setSstFileManager(SstFileManager sstFileManager);
/**
* Any internal progress/error information generated by
* the db will be written to the Logger if it is non-nullptr,
* or to a file stored in the same directory as the DB
* contents if info_log is nullptr.
*
* Default: nullptr
*
* @param logger {@link Logger} instance.
* @return the instance of the current object.
*/
T setLogger(Logger logger);
/**
* Sets the RocksDB log level. Default level is INFO
*
* @param infoLogLevel log level to set.
* @return the instance of the current object.
*/
T setInfoLogLevel(InfoLogLevel infoLogLevel);
/**
* Returns currently set log level.
* @return {@link org.rocksdb.InfoLogLevel} instance.
*/
InfoLogLevel infoLogLevel();
/**
* If {@link MutableDBOptionsInterface#maxOpenFiles()} is -1, DB will open
* all files on DB::Open(). You can use this option to increase the number
* of threads used to open the files.
*
* Default: 16
*
* @param maxFileOpeningThreads the maximum number of threads to use to
* open files
*
* @return the reference to the current options.
*/
T setMaxFileOpeningThreads(int maxFileOpeningThreads);
/**
* If {@link MutableDBOptionsInterface#maxOpenFiles()} is -1, DB will open all
* files on DB::Open(). You can use this option to increase the number of
* threads used to open the files.
*
* Default: 16
*
* @return the maximum number of threads to use to open files
*/
int maxFileOpeningThreads();
/**
* Sets the statistics object which collects metrics about database operations.
* Statistics objects should not be shared between DB instances as
* it does not use any locks to prevent concurrent updates.
*
* @param statistics The statistics to set
*
* @return the instance of the current object.
*
* @see RocksDB#open(org.rocksdb.Options, String)
*/
T setStatistics(final Statistics statistics);
/**
* Returns statistics object.
*
* @return the instance of the statistics object or null if there is no
* statistics object.
*
* @see #setStatistics(Statistics)
*/
Statistics statistics();
/**
* If true, then every store to stable storage will issue a fsync.
* If false, then every store to stable storage will issue a fdatasync.
* This parameter should be set to true while storing data to
* filesystem like ext3 that can lose files after a reboot.
* Default: false
*
* @param useFsync a boolean flag to specify whether to use fsync
* @return the instance of the current object.
*/
T setUseFsync(boolean useFsync);
/**
* If true, then every store to stable storage will issue a fsync.
* If false, then every store to stable storage will issue a fdatasync.
* This parameter should be set to true while storing data to
* filesystem like ext3 that can lose files after a reboot.
*
* @return boolean value indicating if fsync is used.
*/
boolean useFsync();
/**
* A list of paths where SST files can be put into, with its target size.
* Newer data is placed into paths specified earlier in the vector while
* older data gradually moves to paths specified later in the vector.
*
* For example, you have a flash device with 10GB allocated for the DB,
* as well as a hard drive of 2TB, you should config it to be:
* [{"/flash_path", 10GB}, {"/hard_drive", 2TB}]
*
* The system will try to guarantee data under each path is close to but
* not larger than the target size. But current and future file sizes used
* by determining where to place a file are based on best-effort estimation,
* which means there is a chance that the actual size under the directory
* is slightly more than target size under some workloads. User should give
* some buffer room for those cases.
*
* If none of the paths has sufficient room to place a file, the file will
* be placed to the last path anyway, despite to the target size.
*
* Placing newer data to earlier paths is also best-efforts. User should
* expect user files to be placed in higher levels in some extreme cases.
*
* If left empty, only one path will be used, which is db_name passed when
* opening the DB.
*
* Default: empty
*
* @param dbPaths the paths and target sizes
*
* @return the reference to the current options
*/
T setDbPaths(final Collection dbPaths);
/**
* A list of paths where SST files can be put into, with its target size.
* Newer data is placed into paths specified earlier in the vector while
* older data gradually moves to paths specified later in the vector.
*
* For example, you have a flash device with 10GB allocated for the DB,
* as well as a hard drive of 2TB, you should config it to be:
* [{"/flash_path", 10GB}, {"/hard_drive", 2TB}]
*
* The system will try to guarantee data under each path is close to but
* not larger than the target size. But current and future file sizes used
* by determining where to place a file are based on best-effort estimation,
* which means there is a chance that the actual size under the directory
* is slightly more than target size under some workloads. User should give
* some buffer room for those cases.
*
* If none of the paths has sufficient room to place a file, the file will
* be placed to the last path anyway, despite to the target size.
*
* Placing newer data to earlier paths is also best-efforts. User should
* expect user files to be placed in higher levels in some extreme cases.
*
* If left empty, only one path will be used, which is db_name passed when
* opening the DB.
*
* Default: {@link java.util.Collections#emptyList()}
*
* @return dbPaths the paths and target sizes
*/
List dbPaths();
/**
* This specifies the info LOG dir.
* If it is empty, the log files will be in the same dir as data.
* If it is non empty, the log files will be in the specified dir,
* and the db data dir's absolute path will be used as the log file
* name's prefix.
*
* @param dbLogDir the path to the info log directory
* @return the instance of the current object.
*/
T setDbLogDir(String dbLogDir);
/**
* Returns the directory of info log.
*
* If it is empty, the log files will be in the same dir as data.
* If it is non empty, the log files will be in the specified dir,
* and the db data dir's absolute path will be used as the log file
* name's prefix.
*
* @return the path to the info log directory
*/
String dbLogDir();
/**
* This specifies the absolute dir path for write-ahead logs (WAL).
* If it is empty, the log files will be in the same dir as data,
* dbname is used as the data dir by default
* If it is non empty, the log files will be in kept the specified dir.
* When destroying the db,
* all log files in wal_dir and the dir itself is deleted
*
* @param walDir the path to the write-ahead-log directory.
* @return the instance of the current object.
*/
T setWalDir(String walDir);
/**
* Returns the path to the write-ahead-logs (WAL) directory.
*
* If it is empty, the log files will be in the same dir as data,
* dbname is used as the data dir by default
* If it is non empty, the log files will be in kept the specified dir.
* When destroying the db,
* all log files in wal_dir and the dir itself is deleted
*
* @return the path to the write-ahead-logs (WAL) directory.
*/
String walDir();
/**
* The periodicity when obsolete files get deleted. The default
* value is 6 hours. The files that get out of scope by compaction
* process will still get automatically delete on every compaction,
* regardless of this setting
*
* @param micros the time interval in micros
* @return the instance of the current object.
*/
T setDeleteObsoleteFilesPeriodMicros(long micros);
/**
* The periodicity when obsolete files get deleted. The default
* value is 6 hours. The files that get out of scope by compaction
* process will still get automatically delete on every compaction,
* regardless of this setting
*
* @return the time interval in micros when obsolete files will be deleted.
*/
long deleteObsoleteFilesPeriodMicros();
/**
* This value represents the maximum number of threads that will
* concurrently perform a compaction job by breaking it into multiple,
* smaller ones that are run simultaneously.
* Default: 1 (i.e. no subcompactions)
*
* @param maxSubcompactions The maximum number of threads that will
* concurrently perform a compaction job
*
* @return the instance of the current object.
*/
T setMaxSubcompactions(int maxSubcompactions);
/**
* This value represents the maximum number of threads that will
* concurrently perform a compaction job by breaking it into multiple,
* smaller ones that are run simultaneously.
* Default: 1 (i.e. no subcompactions)
*
* @return The maximum number of threads that will concurrently perform a
* compaction job
*/
int maxSubcompactions();
/**
* NOT SUPPORTED ANYMORE: RocksDB automatically decides this based on the
* value of max_background_jobs. For backwards compatibility we will set
* `max_background_jobs = max_background_compactions + max_background_flushes`
* in the case where user sets at least one of `max_background_compactions` or
* `max_background_flushes`.
*
* Specifies the maximum number of concurrent background flush jobs.
* If you're increasing this, also consider increasing number of threads in
* HIGH priority thread pool. For more information, see
* Default: -1
*
* @param maxBackgroundFlushes number of max concurrent flush jobs
* @return the instance of the current object.
*
* @see RocksEnv#setBackgroundThreads(int)
* @see RocksEnv#setBackgroundThreads(int, Priority)
* @see MutableDBOptionsInterface#maxBackgroundCompactions()
*
* @deprecated Use {@link MutableDBOptionsInterface#setMaxBackgroundJobs(int)}
*/
@Deprecated
T setMaxBackgroundFlushes(int maxBackgroundFlushes);
/**
* NOT SUPPORTED ANYMORE: RocksDB automatically decides this based on the
* value of max_background_jobs. For backwards compatibility we will set
* `max_background_jobs = max_background_compactions + max_background_flushes`
* in the case where user sets at least one of `max_background_compactions` or
* `max_background_flushes`.
*
* Returns the maximum number of concurrent background flush jobs.
* If you're increasing this, also consider increasing number of threads in
* HIGH priority thread pool. For more information, see
* Default: -1
*
* @return the maximum number of concurrent background flush jobs.
* @see RocksEnv#setBackgroundThreads(int)
* @see RocksEnv#setBackgroundThreads(int, Priority)
*/
@Deprecated
int maxBackgroundFlushes();
/**
* Specifies the maximum size of a info log file. If the current log file
* is larger than `max_log_file_size`, a new info log file will
* be created.
* If 0, all logs will be written to one log file.
*
* @param maxLogFileSize the maximum size of a info log file.
* @return the instance of the current object.
* @throws java.lang.IllegalArgumentException thrown on 32-Bit platforms
* while overflowing the underlying platform specific value.
*/
T setMaxLogFileSize(long maxLogFileSize);
/**
* Returns the maximum size of a info log file. If the current log file
* is larger than this size, a new info log file will be created.
* If 0, all logs will be written to one log file.
*
* @return the maximum size of the info log file.
*/
long maxLogFileSize();
/**
* Specifies the time interval for the info log file to roll (in seconds).
* If specified with non-zero value, log file will be rolled
* if it has been active longer than `log_file_time_to_roll`.
* Default: 0 (disabled)
*
* @param logFileTimeToRoll the time interval in seconds.
* @return the instance of the current object.
* @throws java.lang.IllegalArgumentException thrown on 32-Bit platforms
* while overflowing the underlying platform specific value.
*/
T setLogFileTimeToRoll(long logFileTimeToRoll);
/**
* Returns the time interval for the info log file to roll (in seconds).
* If specified with non-zero value, log file will be rolled
* if it has been active longer than `log_file_time_to_roll`.
* Default: 0 (disabled)
*
* @return the time interval in seconds.
*/
long logFileTimeToRoll();
/**
* Specifies the maximum number of info log files to be kept.
* Default: 1000
*
* @param keepLogFileNum the maximum number of info log files to be kept.
* @return the instance of the current object.
* @throws java.lang.IllegalArgumentException thrown on 32-Bit platforms
* while overflowing the underlying platform specific value.
*/
T setKeepLogFileNum(long keepLogFileNum);
/**
* Returns the maximum number of info log files to be kept.
* Default: 1000
*
* @return the maximum number of info log files to be kept.
*/
long keepLogFileNum();
/**
* Recycle log files.
*
* If non-zero, we will reuse previously written log files for new
* logs, overwriting the old data. The value indicates how many
* such files we will keep around at any point in time for later
* use.
*
* This is more efficient because the blocks are already
* allocated and fdatasync does not need to update the inode after
* each write.
*
* Default: 0
*
* @param recycleLogFileNum the number of log files to keep for recycling
*
* @return the reference to the current options
*/
T setRecycleLogFileNum(long recycleLogFileNum);
/**
* Recycle log files.
*
* If non-zero, we will reuse previously written log files for new
* logs, overwriting the old data. The value indicates how many
* such files we will keep around at any point in time for later
* use.
*
* This is more efficient because the blocks are already
* allocated and fdatasync does not need to update the inode after
* each write.
*
* Default: 0
*
* @return the number of log files kept for recycling
*/
long recycleLogFileNum();
/**
* Manifest file is rolled over on reaching this limit.
* The older manifest file be deleted.
* The default value is 1GB so that the manifest file can grow, but not
* reach the limit of storage capacity.
*
* @param maxManifestFileSize the size limit of a manifest file.
* @return the instance of the current object.
*/
T setMaxManifestFileSize(long maxManifestFileSize);
/**
* Manifest file is rolled over on reaching this limit.
* The older manifest file be deleted.
* The default value is 1GB so that the manifest file can grow, but not
* reach the limit of storage capacity.
*
* @return the size limit of a manifest file.
*/
long maxManifestFileSize();
/**
* Number of shards used for table cache.
*
* @param tableCacheNumshardbits the number of chards
* @return the instance of the current object.
*/
T setTableCacheNumshardbits(int tableCacheNumshardbits);
/**
* Number of shards used for table cache.
*
* @return the number of shards used for table cache.
*/
int tableCacheNumshardbits();
/**
* {@link #walTtlSeconds()} and {@link #walSizeLimitMB()} affect how archived logs
* will be deleted.
*
* - If both set to 0, logs will be deleted asap and will not get into
* the archive.
* - If WAL_ttl_seconds is 0 and WAL_size_limit_MB is not 0,
* WAL files will be checked every 10 min and if total size is greater
* then WAL_size_limit_MB, they will be deleted starting with the
* earliest until size_limit is met. All empty files will be deleted.
* - If WAL_ttl_seconds is not 0 and WAL_size_limit_MB is 0, then
* WAL files will be checked every WAL_ttl_seconds / 2 and those that
* are older than WAL_ttl_seconds will be deleted.
* - If both are not 0, WAL files will be checked every 10 min and both
* checks will be performed with ttl being first.
*
*
* @param walTtlSeconds the ttl seconds
* @return the instance of the current object.
* @see #setWalSizeLimitMB(long)
*/
T setWalTtlSeconds(long walTtlSeconds);
/**
* WalTtlSeconds() and walSizeLimitMB() affect how archived logs
* will be deleted.
*
* - If both set to 0, logs will be deleted asap and will not get into
* the archive.
* - If WAL_ttl_seconds is 0 and WAL_size_limit_MB is not 0,
* WAL files will be checked every 10 min and if total size is greater
* then WAL_size_limit_MB, they will be deleted starting with the
* earliest until size_limit is met. All empty files will be deleted.
* - If WAL_ttl_seconds is not 0 and WAL_size_limit_MB is 0, then
* WAL files will be checked every WAL_ttl_seconds / 2 and those that
* are older than WAL_ttl_seconds will be deleted.
* - If both are not 0, WAL files will be checked every 10 min and both
* checks will be performed with ttl being first.
*
*
* @return the wal-ttl seconds
* @see #walSizeLimitMB()
*/
long walTtlSeconds();
/**
* WalTtlSeconds() and walSizeLimitMB() affect how archived logs
* will be deleted.
*
* - If both set to 0, logs will be deleted asap and will not get into
* the archive.
* - If WAL_ttl_seconds is 0 and WAL_size_limit_MB is not 0,
* WAL files will be checked every 10 min and if total size is greater
* then WAL_size_limit_MB, they will be deleted starting with the
* earliest until size_limit is met. All empty files will be deleted.
* - If WAL_ttl_seconds is not 0 and WAL_size_limit_MB is 0, then
* WAL files will be checked every WAL_ttl_secondsi / 2 and those that
* are older than WAL_ttl_seconds will be deleted.
* - If both are not 0, WAL files will be checked every 10 min and both
* checks will be performed with ttl being first.
*
*
* @param sizeLimitMB size limit in mega-bytes.
* @return the instance of the current object.
* @see #setWalSizeLimitMB(long)
*/
T setWalSizeLimitMB(long sizeLimitMB);
/**
* {@link #walTtlSeconds()} and {@code #walSizeLimitMB()} affect how archived logs
* will be deleted.
*
* - If both set to 0, logs will be deleted asap and will not get into
* the archive.
* - If WAL_ttl_seconds is 0 and WAL_size_limit_MB is not 0,
* WAL files will be checked every 10 min and if total size is greater
* then WAL_size_limit_MB, they will be deleted starting with the
* earliest until size_limit is met. All empty files will be deleted.
* - If WAL_ttl_seconds is not 0 and WAL_size_limit_MB is 0, then
* WAL files will be checked every WAL_ttl_seconds i / 2 and those that
* are older than WAL_ttl_seconds will be deleted.
* - If both are not 0, WAL files will be checked every 10 min and both
* checks will be performed with ttl being first.
*
* @return size limit in mega-bytes.
* @see #walSizeLimitMB()
*/
long walSizeLimitMB();
/**
* The maximum limit of number of bytes that are written in a single batch
* of WAL or memtable write. It is followed when the leader write size
* is larger than 1/8 of this limit.
*
* Default: 1 MB
*
* @param maxWriteBatchGroupSizeBytes the maximum limit of number of bytes, see description.
* @return the instance of the current object.
*/
T setMaxWriteBatchGroupSizeBytes(final long maxWriteBatchGroupSizeBytes);
/**
* The maximum limit of number of bytes that are written in a single batch
* of WAL or memtable write. It is followed when the leader write size
* is larger than 1/8 of this limit.
*
* Default: 1 MB
*
* @return the maximum limit of number of bytes, see description.
*/
long maxWriteBatchGroupSizeBytes();
/**
* Number of bytes to preallocate (via fallocate) the manifest
* files. Default is 4mb, which is reasonable to reduce random IO
* as well as prevent overallocation for mounts that preallocate
* large amounts of data (such as xfs's allocsize option).
*
* @param size the size in byte
* @return the instance of the current object.
* @throws java.lang.IllegalArgumentException thrown on 32-Bit platforms
* while overflowing the underlying platform specific value.
*/
T setManifestPreallocationSize(long size);
/**
* Number of bytes to preallocate (via fallocate) the manifest
* files. Default is 4mb, which is reasonable to reduce random IO
* as well as prevent overallocation for mounts that preallocate
* large amounts of data (such as xfs's allocsize option).
*
* @return size in bytes.
*/
long manifestPreallocationSize();
/**
* Enable the OS to use direct I/O for reading sst tables.
* Default: false
*
* @param useDirectReads if true, then direct read is enabled
* @return the instance of the current object.
*/
T setUseDirectReads(boolean useDirectReads);
/**
* Enable the OS to use direct I/O for reading sst tables.
* Default: false
*
* @return if true, then direct reads are enabled
*/
boolean useDirectReads();
/**
* Enable the OS to use direct reads and writes in flush and
* compaction
* Default: false
*
* @param useDirectIoForFlushAndCompaction if true, then direct
* I/O will be enabled for background flush and compactions
* @return the instance of the current object.
*/
T setUseDirectIoForFlushAndCompaction(boolean useDirectIoForFlushAndCompaction);
/**
* Enable the OS to use direct reads and writes in flush and
* compaction
*
* @return if true, then direct I/O is enabled for flush and
* compaction
*/
boolean useDirectIoForFlushAndCompaction();
/**
* Whether fallocate calls are allowed
*
* @param allowFAllocate false if fallocate() calls are bypassed
*
* @return the reference to the current options.
*/
T setAllowFAllocate(boolean allowFAllocate);
/**
* Whether fallocate calls are allowed
*
* @return false if fallocate() calls are bypassed
*/
boolean allowFAllocate();
/**
* Allow the OS to mmap file for reading sst tables.
* Default: false
*
* @param allowMmapReads true if mmap reads are allowed.
* @return the instance of the current object.
*/
T setAllowMmapReads(boolean allowMmapReads);
/**
* Allow the OS to mmap file for reading sst tables.
* Default: false
*
* @return true if mmap reads are allowed.
*/
boolean allowMmapReads();
/**
* Allow the OS to mmap file for writing. Default: false
*
* @param allowMmapWrites true if mmap writes are allowd.
* @return the instance of the current object.
*/
T setAllowMmapWrites(boolean allowMmapWrites);
/**
* Allow the OS to mmap file for writing. Default: false
*
* @return true if mmap writes are allowed.
*/
boolean allowMmapWrites();
/**
* Disable child process inherit open files. Default: true
*
* @param isFdCloseOnExec true if child process inheriting open
* files is disabled.
* @return the instance of the current object.
*/
T setIsFdCloseOnExec(boolean isFdCloseOnExec);
/**
* Disable child process inherit open files. Default: true
*
* @return true if child process inheriting open files is disabled.
*/
boolean isFdCloseOnExec();
/**
* If set true, will hint the underlying file system that the file
* access pattern is random, when a sst file is opened.
* Default: true
*
* @param adviseRandomOnOpen true if hinting random access is on.
* @return the instance of the current object.
*/
T setAdviseRandomOnOpen(boolean adviseRandomOnOpen);
/**
* If set true, will hint the underlying file system that the file
* access pattern is random, when a sst file is opened.
* Default: true
*
* @return true if hinting random access is on.
*/
boolean adviseRandomOnOpen();
/**
* Amount of data to build up in memtables across all column
* families before writing to disk.
*
* This is distinct from {@link ColumnFamilyOptions#writeBufferSize()},
* which enforces a limit for a single memtable.
*
* This feature is disabled by default. Specify a non-zero value
* to enable it.
*
* Default: 0 (disabled)
*
* @param dbWriteBufferSize the size of the write buffer
*
* @return the reference to the current options.
*/
T setDbWriteBufferSize(long dbWriteBufferSize);
/**
* Use passed {@link WriteBufferManager} to control memory usage across
* multiple column families and/or DB instances.
*
* Check
* https://github.com/facebook/rocksdb/wiki/Write-Buffer-Manager
* for more details on when to use it
*
* @param writeBufferManager The WriteBufferManager to use
* @return the reference of the current options.
*/
T setWriteBufferManager(final WriteBufferManager writeBufferManager);
/**
* Reference to {@link WriteBufferManager} used by it.
*
* Default: null (Disabled)
*
* @return a reference to WriteBufferManager
*/
WriteBufferManager writeBufferManager();
/**
* Amount of data to build up in memtables across all column
* families before writing to disk.
*
* This is distinct from {@link ColumnFamilyOptions#writeBufferSize()},
* which enforces a limit for a single memtable.
*
* This feature is disabled by default. Specify a non-zero value
* to enable it.
*
* Default: 0 (disabled)
*
* @return the size of the write buffer
*/
long dbWriteBufferSize();
/**
* Specify the file access pattern once a compaction is started.
* It will be applied to all input files of a compaction.
*
* Default: {@link AccessHint#NORMAL}
*
* @param accessHint The access hint
*
* @return the reference to the current options.
*/
T setAccessHintOnCompactionStart(final AccessHint accessHint);
/**
* Specify the file access pattern once a compaction is started.
* It will be applied to all input files of a compaction.
*
* Default: {@link AccessHint#NORMAL}
*
* @return The access hint
*/
AccessHint accessHintOnCompactionStart();
/**
* If true, always create a new file descriptor and new table reader
* for compaction inputs. Turn this parameter on may introduce extra
* memory usage in the table reader, if it allocates extra memory
* for indexes. This will allow file descriptor prefetch options
* to be set for compaction input files and not to impact file
* descriptors for the same file used by user queries.
* Suggest to enable {@link BlockBasedTableConfig#cacheIndexAndFilterBlocks()}
* for this mode if using block-based table.
*
* Default: false
*
* @param newTableReaderForCompactionInputs true if a new file descriptor and
* table reader should be created for compaction inputs
*
* @return the reference to the current options.
*/
T setNewTableReaderForCompactionInputs(
boolean newTableReaderForCompactionInputs);
/**
* If true, always create a new file descriptor and new table reader
* for compaction inputs. Turn this parameter on may introduce extra
* memory usage in the table reader, if it allocates extra memory
* for indexes. This will allow file descriptor prefetch options
* to be set for compaction input files and not to impact file
* descriptors for the same file used by user queries.
* Suggest to enable {@link BlockBasedTableConfig#cacheIndexAndFilterBlocks()}
* for this mode if using block-based table.
*
* Default: false
*
* @return true if a new file descriptor and table reader are created for
* compaction inputs
*/
boolean newTableReaderForCompactionInputs();
/**
* This is a maximum buffer size that is used by WinMmapReadableFile in
* unbuffered disk I/O mode. We need to maintain an aligned buffer for
* reads. We allow the buffer to grow until the specified value and then
* for bigger requests allocate one shot buffers. In unbuffered mode we
* always bypass read-ahead buffer at ReadaheadRandomAccessFile
* When read-ahead is required we then make use of
* {@link MutableDBOptionsInterface#compactionReadaheadSize()} value and
* always try to read ahead.
* With read-ahead we always pre-allocate buffer to the size instead of
* growing it up to a limit.
*
* This option is currently honored only on Windows
*
* Default: 1 Mb
*
* Special value: 0 - means do not maintain per instance buffer. Allocate
* per request buffer and avoid locking.
*
* @param randomAccessMaxBufferSize the maximum size of the random access
* buffer
*
* @return the reference to the current options.
*/
T setRandomAccessMaxBufferSize(long randomAccessMaxBufferSize);
/**
* This is a maximum buffer size that is used by WinMmapReadableFile in
* unbuffered disk I/O mode. We need to maintain an aligned buffer for
* reads. We allow the buffer to grow until the specified value and then
* for bigger requests allocate one shot buffers. In unbuffered mode we
* always bypass read-ahead buffer at ReadaheadRandomAccessFile
* When read-ahead is required we then make use of
* {@link MutableDBOptionsInterface#compactionReadaheadSize()} value and
* always try to read ahead. With read-ahead we always pre-allocate buffer
* to the size instead of growing it up to a limit.
*
* This option is currently honored only on Windows
*
* Default: 1 Mb
*
* Special value: 0 - means do not maintain per instance buffer. Allocate
* per request buffer and avoid locking.
*
* @return the maximum size of the random access buffer
*/
long randomAccessMaxBufferSize();
/**
* Use adaptive mutex, which spins in the user space before resorting
* to kernel. This could reduce context switch when the mutex is not
* heavily contended. However, if the mutex is hot, we could end up
* wasting spin time.
* Default: false
*
* @param useAdaptiveMutex true if adaptive mutex is used.
* @return the instance of the current object.
*/
T setUseAdaptiveMutex(boolean useAdaptiveMutex);
/**
* Use adaptive mutex, which spins in the user space before resorting
* to kernel. This could reduce context switch when the mutex is not
* heavily contended. However, if the mutex is hot, we could end up
* wasting spin time.
* Default: false
*
* @return true if adaptive mutex is used.
*/
boolean useAdaptiveMutex();
/**
* Sets the {@link EventListener}s whose callback functions
* will be called when specific RocksDB event happens.
*
* Note: the RocksJava API currently only supports EventListeners implemented in Java.
* It could be extended in future to also support adding/removing EventListeners implemented in
* C++.
*
* @param listeners the listeners who should be notified on various events.
*
* @return the instance of the current object.
*/
T setListeners(final List listeners);
/**
* Sets the {@link EventListener}s whose callback functions
* will be called when specific RocksDB event happens.
*
* Note: the RocksJava API currently only supports EventListeners implemented in Java.
* It could be extended in future to also support adding/removing EventListeners implemented in
* C++.
*
* @return the instance of the current object.
*/
List listeners();
/**
* If true, then the status of the threads involved in this DB will
* be tracked and available via GetThreadList() API.
*
* Default: false
*
* @param enableThreadTracking true to enable tracking
*
* @return the reference to the current options.
*/
T setEnableThreadTracking(boolean enableThreadTracking);
/**
* If true, then the status of the threads involved in this DB will
* be tracked and available via GetThreadList() API.
*
* Default: false
*
* @return true if tracking is enabled
*/
boolean enableThreadTracking();
/**
* By default, a single write thread queue is maintained. The thread gets
* to the head of the queue becomes write batch group leader and responsible
* for writing to WAL and memtable for the batch group.
*
* If {@link #enablePipelinedWrite()} is true, separate write thread queue is
* maintained for WAL write and memtable write. A write thread first enter WAL
* writer queue and then memtable writer queue. Pending thread on the WAL
* writer queue thus only have to wait for previous writers to finish their
* WAL writing but not the memtable writing. Enabling the feature may improve
* write throughput and reduce latency of the prepare phase of two-phase
* commit.
*
* Default: false
*
* @param enablePipelinedWrite true to enabled pipelined writes
*
* @return the reference to the current options.
*/
T setEnablePipelinedWrite(final boolean enablePipelinedWrite);
/**
* Returns true if pipelined writes are enabled.
* See {@link #setEnablePipelinedWrite(boolean)}.
*
* @return true if pipelined writes are enabled, false otherwise.
*/
boolean enablePipelinedWrite();
/**
* Setting {@link #unorderedWrite()} to true trades higher write throughput with
* relaxing the immutability guarantee of snapshots. This violates the
* repeatability one expects from ::Get from a snapshot, as well as
* ::MultiGet and Iterator's consistent-point-in-time view property.
* If the application cannot tolerate the relaxed guarantees, it can implement
* its own mechanisms to work around that and yet benefit from the higher
* throughput. Using TransactionDB with WRITE_PREPARED write policy and
* {@link #twoWriteQueues()} true is one way to achieve immutable snapshots despite
* unordered_write.
*
* By default, i.e., when it is false, rocksdb does not advance the sequence
* number for new snapshots unless all the writes with lower sequence numbers
* are already finished. This provides the immutability that we except from
* snapshots. Moreover, since Iterator and MultiGet internally depend on
* snapshots, the snapshot immutability results into Iterator and MultiGet
* offering consistent-point-in-time view. If set to true, although
* Read-Your-Own-Write property is still provided, the snapshot immutability
* property is relaxed: the writes issued after the snapshot is obtained (with
* larger sequence numbers) will be still not visible to the reads from that
* snapshot, however, there still might be pending writes (with lower sequence
* number) that will change the state visible to the snapshot after they are
* landed to the memtable.
*
* @param unorderedWrite true to enabled unordered write
*
* @return the reference to the current options.
*/
T setUnorderedWrite(final boolean unorderedWrite);
/**
* Returns true if unordered write are enabled.
* See {@link #setUnorderedWrite(boolean)}.
*
* @return true if unordered write are enabled, false otherwise.
*/
boolean unorderedWrite();
/**
* If true, allow multi-writers to update mem tables in parallel.
* Only some memtable factorys support concurrent writes; currently it
* is implemented only for SkipListFactory. Concurrent memtable writes
* are not compatible with inplace_update_support or filter_deletes.
* It is strongly recommended to set
* {@link #setEnableWriteThreadAdaptiveYield(boolean)} if you are going to use
* this feature.
* Default: true
*
* @param allowConcurrentMemtableWrite true to enable concurrent writes
* for the memtable
*
* @return the reference to the current options.
*/
T setAllowConcurrentMemtableWrite(boolean allowConcurrentMemtableWrite);
/**
* If true, allow multi-writers to update mem tables in parallel.
* Only some memtable factorys support concurrent writes; currently it
* is implemented only for SkipListFactory. Concurrent memtable writes
* are not compatible with inplace_update_support or filter_deletes.
* It is strongly recommended to set
* {@link #setEnableWriteThreadAdaptiveYield(boolean)} if you are going to use
* this feature.
* Default: true
*
* @return true if concurrent writes are enabled for the memtable
*/
boolean allowConcurrentMemtableWrite();
/**
* If true, threads synchronizing with the write batch group leader will
* wait for up to {@link #writeThreadMaxYieldUsec()} before blocking on a
* mutex. This can substantially improve throughput for concurrent workloads,
* regardless of whether {@link #allowConcurrentMemtableWrite()} is enabled.
* Default: true
*
* @param enableWriteThreadAdaptiveYield true to enable adaptive yield for the
* write threads
*
* @return the reference to the current options.
*/
T setEnableWriteThreadAdaptiveYield(
boolean enableWriteThreadAdaptiveYield);
/**
* If true, threads synchronizing with the write batch group leader will
* wait for up to {@link #writeThreadMaxYieldUsec()} before blocking on a
* mutex. This can substantially improve throughput for concurrent workloads,
* regardless of whether {@link #allowConcurrentMemtableWrite()} is enabled.
* Default: true
*
* @return true if adaptive yield is enabled
* for the writing threads
*/
boolean enableWriteThreadAdaptiveYield();
/**
* The maximum number of microseconds that a write operation will use
* a yielding spin loop to coordinate with other write threads before
* blocking on a mutex. (Assuming {@link #writeThreadSlowYieldUsec()} is
* set properly) increasing this value is likely to increase RocksDB
* throughput at the expense of increased CPU usage.
* Default: 100
*
* @param writeThreadMaxYieldUsec maximum number of microseconds
*
* @return the reference to the current options.
*/
T setWriteThreadMaxYieldUsec(long writeThreadMaxYieldUsec);
/**
* The maximum number of microseconds that a write operation will use
* a yielding spin loop to coordinate with other write threads before
* blocking on a mutex. (Assuming {@link #writeThreadSlowYieldUsec()} is
* set properly) increasing this value is likely to increase RocksDB
* throughput at the expense of increased CPU usage.
* Default: 100
*
* @return the maximum number of microseconds
*/
long writeThreadMaxYieldUsec();
/**
* The latency in microseconds after which a std::this_thread::yield
* call (sched_yield on Linux) is considered to be a signal that
* other processes or threads would like to use the current core.
* Increasing this makes writer threads more likely to take CPU
* by spinning, which will show up as an increase in the number of
* involuntary context switches.
* Default: 3
*
* @param writeThreadSlowYieldUsec the latency in microseconds
*
* @return the reference to the current options.
*/
T setWriteThreadSlowYieldUsec(long writeThreadSlowYieldUsec);
/**
* The latency in microseconds after which a std::this_thread::yield
* call (sched_yield on Linux) is considered to be a signal that
* other processes or threads would like to use the current core.
* Increasing this makes writer threads more likely to take CPU
* by spinning, which will show up as an increase in the number of
* involuntary context switches.
* Default: 3
*
* @return writeThreadSlowYieldUsec the latency in microseconds
*/
long writeThreadSlowYieldUsec();
/**
* If true, then DB::Open() will not update the statistics used to optimize
* compaction decision by loading table properties from many files.
* Turning off this feature will improve DBOpen time especially in
* disk environment.
*
* Default: false
*
* @param skipStatsUpdateOnDbOpen true if updating stats will be skipped
*
* @return the reference to the current options.
*/
T setSkipStatsUpdateOnDbOpen(boolean skipStatsUpdateOnDbOpen);
/**
* If true, then DB::Open() will not update the statistics used to optimize
* compaction decision by loading table properties from many files.
* Turning off this feature will improve DBOpen time especially in
* disk environment.
*
* Default: false
*
* @return true if updating stats will be skipped
*/
boolean skipStatsUpdateOnDbOpen();
/**
* If true, then {@link RocksDB#open(String)} will not fetch and check sizes of all sst files.
* This may significantly speed up startup if there are many sst files,
* especially when using non-default Env with expensive GetFileSize().
* We'll still check that all required sst files exist.
* If {@code paranoid_checks} is false, this option is ignored, and sst files are
* not checked at all.
*
* Default: false
*
* @param skipCheckingSstFileSizesOnDbOpen if true, then SST file sizes will not be checked
* when calling {@link RocksDB#open(String)}.
* @return the reference to the current options.
*/
T setSkipCheckingSstFileSizesOnDbOpen(final boolean skipCheckingSstFileSizesOnDbOpen);
/**
* If true, then {@link RocksDB#open(String)} will not fetch and check sizes of all sst files.
* This may significantly speed up startup if there are many sst files,
* especially when using non-default Env with expensive GetFileSize().
* We'll still check that all required sst files exist.
* If {@code paranoid_checks} is false, this option is ignored, and sst files are
* not checked at all.
*
* Default: false
*
* @return true, if file sizes will not be checked when calling {@link RocksDB#open(String)}.
*/
boolean skipCheckingSstFileSizesOnDbOpen();
/**
* Recovery mode to control the consistency while replaying WAL
*
* Default: {@link WALRecoveryMode#PointInTimeRecovery}
*
* @param walRecoveryMode The WAL recover mode
*
* @return the reference to the current options.
*/
T setWalRecoveryMode(WALRecoveryMode walRecoveryMode);
/**
* Recovery mode to control the consistency while replaying WAL
*
* Default: {@link WALRecoveryMode#PointInTimeRecovery}
*
* @return The WAL recover mode
*/
WALRecoveryMode walRecoveryMode();
/**
* if set to false then recovery will fail when a prepared
* transaction is encountered in the WAL
*
* Default: false
*
* @param allow2pc true if two-phase-commit is enabled
*
* @return the reference to the current options.
*/
T setAllow2pc(boolean allow2pc);
/**
* if set to false then recovery will fail when a prepared
* transaction is encountered in the WAL
*
* Default: false
*
* @return true if two-phase-commit is enabled
*/
boolean allow2pc();
/**
* A global cache for table-level rows.
*
* Default: null (disabled)
*
* @param rowCache The global row cache
*
* @return the reference to the current options.
*/
T setRowCache(final Cache rowCache);
/**
* A global cache for table-level rows.
*
* Default: null (disabled)
*
* @return The global row cache
*/
Cache rowCache();
/**
* A filter object supplied to be invoked while processing write-ahead-logs
* (WALs) during recovery. The filter provides a way to inspect log
* records, ignoring a particular record or skipping replay.
* The filter is invoked at startup and is invoked from a single-thread
* currently.
*
* @param walFilter the filter for processing WALs during recovery.
*
* @return the reference to the current options.
*/
T setWalFilter(final AbstractWalFilter walFilter);
/**
* Get's the filter for processing WALs during recovery.
* See {@link #setWalFilter(AbstractWalFilter)}.
*
* @return the filter used for processing WALs during recovery.
*/
WalFilter walFilter();
/**
* If true, then DB::Open / CreateColumnFamily / DropColumnFamily
* / SetOptions will fail if options file is not detected or properly
* persisted.
*
* DEFAULT: false
*
* @param failIfOptionsFileError true if we should fail if there is an error
* in the options file
*
* @return the reference to the current options.
*/
T setFailIfOptionsFileError(boolean failIfOptionsFileError);
/**
* If true, then DB::Open / CreateColumnFamily / DropColumnFamily
* / SetOptions will fail if options file is not detected or properly
* persisted.
*
* DEFAULT: false
*
* @return true if we should fail if there is an error in the options file
*/
boolean failIfOptionsFileError();
/**
* If true, then print malloc stats together with rocksdb.stats
* when printing to LOG.
*
* DEFAULT: false
*
* @param dumpMallocStats true if malloc stats should be printed to LOG
*
* @return the reference to the current options.
*/
T setDumpMallocStats(boolean dumpMallocStats);
/**
* If true, then print malloc stats together with rocksdb.stats
* when printing to LOG.
*
* DEFAULT: false
*
* @return true if malloc stats should be printed to LOG
*/
boolean dumpMallocStats();
/**
* By default RocksDB replay WAL logs and flush them on DB open, which may
* create very small SST files. If this option is enabled, RocksDB will try
* to avoid (but not guarantee not to) flush during recovery. Also, existing
* WAL logs will be kept, so that if crash happened before flush, we still
* have logs to recover from.
*
* DEFAULT: false
*
* @param avoidFlushDuringRecovery true to try to avoid (but not guarantee
* not to) flush during recovery
*
* @return the reference to the current options.
*/
T setAvoidFlushDuringRecovery(boolean avoidFlushDuringRecovery);
/**
* By default RocksDB replay WAL logs and flush them on DB open, which may
* create very small SST files. If this option is enabled, RocksDB will try
* to avoid (but not guarantee not to) flush during recovery. Also, existing
* WAL logs will be kept, so that if crash happened before flush, we still
* have logs to recover from.
*
* DEFAULT: false
*
* @return true to try to avoid (but not guarantee not to) flush during
* recovery
*/
boolean avoidFlushDuringRecovery();
/**
* Set this option to true during creation of database if you want
* to be able to ingest behind (call IngestExternalFile() skipping keys
* that already exist, rather than overwriting matching keys).
* Setting this option to true will affect 2 things:
* 1) Disable some internal optimizations around SST file compression
* 2) Reserve bottom-most level for ingested files only.
* 3) Note that num_levels should be >= 3 if this option is turned on.
*
* DEFAULT: false
*
* @param allowIngestBehind true to allow ingest behind, false to disallow.
*
* @return the reference to the current options.
*/
T setAllowIngestBehind(final boolean allowIngestBehind);
/**
* Returns true if ingest behind is allowed.
* See {@link #setAllowIngestBehind(boolean)}.
*
* @return true if ingest behind is allowed, false otherwise.
*/
boolean allowIngestBehind();
/**
* Needed to support differential snapshots.
* If set to true then DB will only process deletes with sequence number
* less than what was set by SetPreserveDeletesSequenceNumber(uint64_t ts).
* Clients are responsible to periodically call this method to advance
* the cutoff time. If this method is never called and preserve_deletes
* is set to true NO deletes will ever be processed.
* At the moment this only keeps normal deletes, SingleDeletes will
* not be preserved.
*
* DEFAULT: false
*
* @param preserveDeletes true to preserve deletes.
*
* @return the reference to the current options.
*/
T setPreserveDeletes(final boolean preserveDeletes);
/**
* Returns true if deletes are preserved.
* See {@link #setPreserveDeletes(boolean)}.
*
* @return true if deletes are preserved, false otherwise.
*/
boolean preserveDeletes();
/**
* If enabled it uses two queues for writes, one for the ones with
* disable_memtable and one for the ones that also write to memtable. This
* allows the memtable writes not to lag behind other writes. It can be used
* to optimize MySQL 2PC in which only the commits, which are serial, write to
* memtable.
*
* DEFAULT: false
*
* @param twoWriteQueues true to enable two write queues, false otherwise.
*
* @return the reference to the current options.
*/
T setTwoWriteQueues(final boolean twoWriteQueues);
/**
* Returns true if two write queues are enabled.
*
* @return true if two write queues are enabled, false otherwise.
*/
boolean twoWriteQueues();
/**
* If true WAL is not flushed automatically after each write. Instead it
* relies on manual invocation of FlushWAL to write the WAL buffer to its
* file.
*
* DEFAULT: false
*
* @param manualWalFlush true to set disable automatic WAL flushing,
* false otherwise.
*
* @return the reference to the current options.
*/
T setManualWalFlush(final boolean manualWalFlush);
/**
* Returns true if automatic WAL flushing is disabled.
* See {@link #setManualWalFlush(boolean)}.
*
* @return true if automatic WAL flushing is disabled, false otherwise.
*/
boolean manualWalFlush();
/**
* If true, RocksDB supports flushing multiple column families and committing
* their results atomically to MANIFEST. Note that it is not
* necessary to set atomic_flush to true if WAL is always enabled since WAL
* allows the database to be restored to the last persistent state in WAL.
* This option is useful when there are column families with writes NOT
* protected by WAL.
* For manual flush, application has to specify which column families to
* flush atomically in {@link RocksDB#flush(FlushOptions, List)}.
* For auto-triggered flush, RocksDB atomically flushes ALL column families.
*
* Currently, any WAL-enabled writes after atomic flush may be replayed
* independently if the process crashes later and tries to recover.
*
* @param atomicFlush true to enable atomic flush of multiple column families.
*
* @return the reference to the current options.
*/
T setAtomicFlush(final boolean atomicFlush);
/**
* Determine if atomic flush of multiple column families is enabled.
*
* See {@link #setAtomicFlush(boolean)}.
*
* @return true if atomic flush is enabled.
*/
boolean atomicFlush();
/**
* If true, working thread may avoid doing unnecessary and long-latency
* operation (such as deleting obsolete files directly or deleting memtable)
* and will instead schedule a background job to do it.
* Use it if you're latency-sensitive.
* If set to true, takes precedence over
* {@link ReadOptions#setBackgroundPurgeOnIteratorCleanup(boolean)}.
*
* @param avoidUnnecessaryBlockingIO If true, working thread may avoid doing unnecessary
* operation.
* @return the reference to the current options.
*/
T setAvoidUnnecessaryBlockingIO(final boolean avoidUnnecessaryBlockingIO);
/**
* If true, working thread may avoid doing unnecessary and long-latency
* operation (such as deleting obsolete files directly or deleting memtable)
* and will instead schedule a background job to do it.
* Use it if you're latency-sensitive.
* If set to true, takes precedence over
* {@link ReadOptions#setBackgroundPurgeOnIteratorCleanup(boolean)}.
*
* @return true, if working thread may avoid doing unnecessary operation.
*/
boolean avoidUnnecessaryBlockingIO();
/**
* If true, automatically persist stats to a hidden column family (column
* family name: ___rocksdb_stats_history___) every
* stats_persist_period_sec seconds; otherwise, write to an in-memory
* struct. User can query through `GetStatsHistory` API.
* If user attempts to create a column family with the same name on a DB
* which have previously set persist_stats_to_disk to true, the column family
* creation will fail, but the hidden column family will survive, as well as
* the previously persisted statistics.
* When peristing stats to disk, the stat name will be limited at 100 bytes.
* Default: false
*
* @param persistStatsToDisk true if stats should be persisted to hidden column family.
* @return the instance of the current object.
*/
T setPersistStatsToDisk(final boolean persistStatsToDisk);
/**
* If true, automatically persist stats to a hidden column family (column
* family name: ___rocksdb_stats_history___) every
* stats_persist_period_sec seconds; otherwise, write to an in-memory
* struct. User can query through `GetStatsHistory` API.
* If user attempts to create a column family with the same name on a DB
* which have previously set persist_stats_to_disk to true, the column family
* creation will fail, but the hidden column family will survive, as well as
* the previously persisted statistics.
* When peristing stats to disk, the stat name will be limited at 100 bytes.
* Default: false
*
* @return true if stats should be persisted to hidden column family.
*/
boolean persistStatsToDisk();
/**
* Historically DB ID has always been stored in Identity File in DB folder.
* If this flag is true, the DB ID is written to Manifest file in addition
* to the Identity file. By doing this 2 problems are solved
* 1. We don't checksum the Identity file where as Manifest file is.
* 2. Since the source of truth for DB is Manifest file DB ID will sit with
* the source of truth. Previously the Identity file could be copied
* independent of Manifest and that can result in wrong DB ID.
* We recommend setting this flag to true.
* Default: false
*
* @param writeDbidToManifest if true, then DB ID will be written to Manifest file.
* @return the instance of the current object.
*/
T setWriteDbidToManifest(final boolean writeDbidToManifest);
/**
* Historically DB ID has always been stored in Identity File in DB folder.
* If this flag is true, the DB ID is written to Manifest file in addition
* to the Identity file. By doing this 2 problems are solved
* 1. We don't checksum the Identity file where as Manifest file is.
* 2. Since the source of truth for DB is Manifest file DB ID will sit with
* the source of truth. Previously the Identity file could be copied
* independent of Manifest and that can result in wrong DB ID.
* We recommend setting this flag to true.
* Default: false
*
* @return true, if DB ID will be written to Manifest file.
*/
boolean writeDbidToManifest();
/**
* The number of bytes to prefetch when reading the log. This is mostly useful
* for reading a remotely located log, as it can save the number of
* round-trips. If 0, then the prefetching is disabled.
*
* Default: 0
*
* @param logReadaheadSize the number of bytes to prefetch when reading the log.
* @return the instance of the current object.
*/
T setLogReadaheadSize(final long logReadaheadSize);
/**
* The number of bytes to prefetch when reading the log. This is mostly useful
* for reading a remotely located log, as it can save the number of
* round-trips. If 0, then the prefetching is disabled.
*
* Default: 0
*
* @return the number of bytes to prefetch when reading the log.
*/
long logReadaheadSize();
/**
* By default, RocksDB recovery fails if any table file referenced in
* MANIFEST are missing after scanning the MANIFEST.
* Best-efforts recovery is another recovery mode that
* tries to restore the database to the most recent point in time without
* missing file.
* Currently not compatible with atomic flush. Furthermore, WAL files will
* not be used for recovery if best_efforts_recovery is true.
* Default: false
*
* @param bestEffortsRecovery if true, RocksDB will use best-efforts mode when recovering.
* @return the instance of the current object.
*/
T setBestEffortsRecovery(final boolean bestEffortsRecovery);
/**
* By default, RocksDB recovery fails if any table file referenced in
* MANIFEST are missing after scanning the MANIFEST.
* Best-efforts recovery is another recovery mode that
* tries to restore the database to the most recent point in time without
* missing file.
* Currently not compatible with atomic flush. Furthermore, WAL files will
* not be used for recovery if best_efforts_recovery is true.
* Default: false
*
* @return true, if RocksDB uses best-efforts mode when recovering.
*/
boolean bestEffortsRecovery();
/**
* It defines how many times db resume is called by a separate thread when
* background retryable IO Error happens. When background retryable IO
* Error happens, SetBGError is called to deal with the error. If the error
* can be auto-recovered (e.g., retryable IO Error during Flush or WAL write),
* then db resume is called in background to recover from the error. If this
* value is 0 or negative, db resume will not be called.
*
* Default: INT_MAX
*
* @param maxBgerrorResumeCount maximum number of times db resume should be called when IO Error
* happens.
* @return the instance of the current object.
*/
T setMaxBgErrorResumeCount(final int maxBgerrorResumeCount);
/**
* It defines how many times db resume is called by a separate thread when
* background retryable IO Error happens. When background retryable IO
* Error happens, SetBGError is called to deal with the error. If the error
* can be auto-recovered (e.g., retryable IO Error during Flush or WAL write),
* then db resume is called in background to recover from the error. If this
* value is 0 or negative, db resume will not be called.
*
* Default: INT_MAX
*
* @return maximum number of times db resume should be called when IO Error happens.
*/
int maxBgerrorResumeCount();
/**
* If max_bgerror_resume_count is ≥ 2, db resume is called multiple times.
* This option decides how long to wait to retry the next resume if the
* previous resume fails and satisfy redo resume conditions.
*
* Default: 1000000 (microseconds).
*
* @param bgerrorResumeRetryInterval how many microseconds to wait between DB resume attempts.
* @return the instance of the current object.
*/
T setBgerrorResumeRetryInterval(final long bgerrorResumeRetryInterval);
/**
* If max_bgerror_resume_count is ≥ 2, db resume is called multiple times.
* This option decides how long to wait to retry the next resume if the
* previous resume fails and satisfy redo resume conditions.
*
* Default: 1000000 (microseconds).
*
* @return the instance of the current object.
*/
long bgerrorResumeRetryInterval();
}