MutableDBOptionsInterface (schwefel 7.2.2.1 API)

All Known Implementing Classes:

DBOptions, MutableDBOptions.MutableDBOptionsBuilder, Options
```
public interface MutableDBOptionsInterface<T extends MutableDBOptionsInterface<T>>
```

Method Summary

All Methods Instance Methods Abstract Methods Deprecated Methods
Modifier and Type	Method and Description
`boolean`	`avoidFlushDuringShutdown()` By default RocksDB will flush all memtables on DB close if there are unpersisted data (i.e. with WAL disabled) The flush can be skip to speedup DB close.
`long`	`bytesPerSync()` Allows OS to incrementally sync files to disk while they are being written, asynchronously, in the background.
`long`	`compactionReadaheadSize()` If non-zero, we perform bigger reads when doing compaction.
`long`	`delayedWriteRate()` The limited write rate to DB if `ColumnFamilyOptions.softPendingCompactionBytesLimit()` or `ColumnFamilyOptions.level0SlowdownWritesTrigger()` is triggered, or we are writing to the last mem table allowed and we allow more than 3 mem tables.
`long`	`deleteObsoleteFilesPeriodMicros()` The periodicity when obsolete files get deleted.
`int`	`maxBackgroundCompactions()` Deprecated. Use `setMaxBackgroundJobs(int)`
`int`	`maxBackgroundJobs()` Returns the maximum number of concurrent background jobs (both flushes and compactions combined).
`int`	`maxOpenFiles()` Number of open files that can be used by the DB.
`long`	`maxTotalWalSize()` Returns the max total write-ahead log size.
`T`	`setAvoidFlushDuringShutdown(boolean avoidFlushDuringShutdown)` By default RocksDB will flush all memtables on DB close if there are unpersisted data (i.e. with WAL disabled) The flush can be skip to speedup DB close.
`T`	`setBytesPerSync(long bytesPerSync)` Allows OS to incrementally sync files to disk while they are being written, asynchronously, in the background.
`T`	`setCompactionReadaheadSize(long compactionReadaheadSize)` If non-zero, we perform bigger reads when doing compaction.
`T`	`setDelayedWriteRate(long delayedWriteRate)` The limited write rate to DB if `ColumnFamilyOptions.softPendingCompactionBytesLimit()` or `ColumnFamilyOptions.level0SlowdownWritesTrigger()` is triggered, or we are writing to the last mem table allowed and we allow more than 3 mem tables.
`T`	`setDeleteObsoleteFilesPeriodMicros(long micros)` The periodicity when obsolete files get deleted.
`T`	`setMaxBackgroundCompactions(int maxBackgroundCompactions)` Deprecated. Use `setMaxBackgroundJobs(int)`
`T`	`setMaxBackgroundJobs(int maxBackgroundJobs)` Specifies the maximum number of concurrent background jobs (both flushes and compactions combined).
`T`	`setMaxOpenFiles(int maxOpenFiles)` Number of open files that can be used by the DB.
`T`	`setMaxTotalWalSize(long maxTotalWalSize)` Set the max total write-ahead log size.
`T`	`setStatsDumpPeriodSec(int statsDumpPeriodSec)` if not zero, dump rocksdb.stats to LOG every stats_dump_period_sec Default: 600 (10 minutes)
`T`	`setStatsHistoryBufferSize(long statsHistoryBufferSize)` If not zero, periodically take stats snapshots and store in memory, the memory size for stats snapshots is capped at `statsHistoryBufferSize` Default: 1MB
`T`	`setStatsPersistPeriodSec(int statsPersistPeriodSec)` If not zero, dump rocksdb.stats to RocksDB every `statsPersistPeriodSec` Default: 600
`T`	`setStrictBytesPerSync(boolean strictBytesPerSync)` When true, guarantees WAL files have at most `walBytesPerSync()` bytes submitted for writeback at any given time, and SST files have at most `bytesPerSync()` bytes pending writeback at any given time.
`T`	`setWalBytesPerSync(long walBytesPerSync)` Same as `setBytesPerSync(long)` , but applies to WAL files Default: 0, turned off
`T`	`setWritableFileMaxBufferSize(long writableFileMaxBufferSize)` This is the maximum buffer size that is used by WritableFileWriter.
`int`	`statsDumpPeriodSec()` If not zero, dump rocksdb.stats to LOG every stats_dump_period_sec Default: 600 (10 minutes)
`long`	`statsHistoryBufferSize()` If not zero, periodically take stats snapshots and store in memory, the memory size for stats snapshots is capped at `statsHistoryBufferSize`
`int`	`statsPersistPeriodSec()` If not zero, dump rocksdb.stats to RocksDB every `statsPersistPeriodSec`
`boolean`	`strictBytesPerSync()` Return the strict byte limit per sync.
`long`	`walBytesPerSync()` Same as `bytesPerSync()` , but applies to WAL files Default: 0, turned off
`long`	`writableFileMaxBufferSize()` This is the maximum buffer size that is used by WritableFileWriter.

- Method Detail
  - setMaxBackgroundJobs
```
T setMaxBackgroundJobs(int maxBackgroundJobs)
```
    Specifies the maximum number of concurrent background jobs (both flushes and compactions combined). Default: 2
    
    Parameters:
    
    maxBackgroundJobs - number of max concurrent background jobs
    
    Returns:
    
    the instance of the current object.
  - maxBackgroundJobs
```
int maxBackgroundJobs()
```
    Returns the maximum number of concurrent background jobs (both flushes and compactions combined). Default: 2
    
    Returns:
    
    the maximum number of concurrent background jobs.
  - setMaxBackgroundCompactions
```
@Deprecated
T setMaxBackgroundCompactions(int maxBackgroundCompactions)
```
    Deprecated. Use setMaxBackgroundJobs(int)
    
    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` (we replace -1 by 1 in case one option is unset). Specifies the maximum number of concurrent background compaction jobs, submitted to the default LOW priority thread pool. If you're increasing this, also consider increasing number of threads in LOW priority thread pool. For more information, see Default: -1
    
    Parameters:
    
    maxBackgroundCompactions - the maximum number of background compaction jobs.
    
    Returns:
    
    the instance of the current object.
    
    See Also:
    
    Env.setBackgroundThreads(int), Env.setBackgroundThreads(int, Priority), DBOptionsInterface.maxBackgroundFlushes()
  - maxBackgroundCompactions
```
@Deprecated
int maxBackgroundCompactions()
```
    Deprecated. Use setMaxBackgroundJobs(int)
    
    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` (we replace -1 by 1 in case one option is unset). Returns the maximum number of concurrent background compaction jobs, submitted to the default LOW priority thread pool. When increasing this number, we may also want to consider increasing number of threads in LOW priority thread pool. Default: -1
    
    Returns:
    
    the maximum number of concurrent background compaction jobs.
    
    See Also:
    
    Env.setBackgroundThreads(int), Env.setBackgroundThreads(int, Priority)
  - setAvoidFlushDuringShutdown
```
T setAvoidFlushDuringShutdown(boolean avoidFlushDuringShutdown)
```
    By default RocksDB will flush all memtables on DB close if there are unpersisted data (i.e. with WAL disabled) The flush can be skip to speedup DB close. Unpersisted data WILL BE LOST. DEFAULT: false Dynamically changeable through RocksDB.setOptions(ColumnFamilyHandle, MutableColumnFamilyOptions) API.
    
    Parameters:
    
    avoidFlushDuringShutdown - true if we should avoid flush during shutdown
    
    Returns:
    
    the reference to the current options.
  - avoidFlushDuringShutdown
```
boolean avoidFlushDuringShutdown()
```
    By default RocksDB will flush all memtables on DB close if there are unpersisted data (i.e. with WAL disabled) The flush can be skip to speedup DB close. Unpersisted data WILL BE LOST. DEFAULT: false Dynamically changeable through RocksDB.setOptions(ColumnFamilyHandle, MutableColumnFamilyOptions) API.
    
    Returns:
    
    true if we should avoid flush during shutdown
  - setWritableFileMaxBufferSize
```
T setWritableFileMaxBufferSize(long writableFileMaxBufferSize)
```
    This is the maximum buffer size that is used by WritableFileWriter. On Windows, we need to maintain an aligned buffer for writes. We allow the buffer to grow until it's size hits the limit. Default: 1024 * 1024 (1 MB)
    
    Parameters:
    
    writableFileMaxBufferSize - the maximum buffer size
    
    Returns:
    
    the reference to the current options.
  - writableFileMaxBufferSize
```
long writableFileMaxBufferSize()
```
    This is the maximum buffer size that is used by WritableFileWriter. On Windows, we need to maintain an aligned buffer for writes. We allow the buffer to grow until it's size hits the limit. Default: 1024 * 1024 (1 MB)
    
    Returns:
    
    the maximum buffer size
  - setDelayedWriteRate
```
T setDelayedWriteRate(long delayedWriteRate)
```
    The limited write rate to DB if ColumnFamilyOptions.softPendingCompactionBytesLimit() or ColumnFamilyOptions.level0SlowdownWritesTrigger() is triggered, or we are writing to the last mem table allowed and we allow more than 3 mem tables. It is calculated using size of user write requests before compression. RocksDB may decide to slow down more if the compaction still gets behind further. If the value is 0, we will infer a value from `rater_limiter` value if it is not empty, or 16MB if `rater_limiter` is empty. Note that if users change the rate in `rate_limiter` after DB is opened, `delayed_write_rate` won't be adjusted. Unit: bytes per second. Default: 0 Dynamically changeable through RocksDB.setDBOptions(MutableDBOptions).
    
    Parameters:
    
    delayedWriteRate - the rate in bytes per second
    
    Returns:
    
    the reference to the current options.
  - delayedWriteRate
```
long delayedWriteRate()
```
    The limited write rate to DB if ColumnFamilyOptions.softPendingCompactionBytesLimit() or ColumnFamilyOptions.level0SlowdownWritesTrigger() is triggered, or we are writing to the last mem table allowed and we allow more than 3 mem tables. It is calculated using size of user write requests before compression. RocksDB may decide to slow down more if the compaction still gets behind further. If the value is 0, we will infer a value from `rater_limiter` value if it is not empty, or 16MB if `rater_limiter` is empty. Note that if users change the rate in `rate_limiter` after DB is opened, `delayed_write_rate` won't be adjusted. Unit: bytes per second. Default: 0 Dynamically changeable through RocksDB.setDBOptions(MutableDBOptions).
    
    Returns:
    
    the rate in bytes per second
  - setMaxTotalWalSize
```
T setMaxTotalWalSize(long maxTotalWalSize)
```
    Set the max total write-ahead log size. Once write-ahead logs exceed this size, we will start forcing the flush of column families whose memtables are backed by the oldest live WAL file
    
    The oldest WAL files are the ones that are causing all the space amplification.
    For example, with 15 column families, each with write_buffer_size = 128 MB max_write_buffer_number = 6 max_total_wal_size will be calculated to be [15 * 128MB * 6] * 4 = 45GB
    The RocksDB wiki has some discussion about how the WAL interacts with memtables and flushing of column families, at ...
    
    If set to 0 (default), we will dynamically choose the WAL size limit to be [sum of all write_buffer_size * max_write_buffer_number] * 4
    
    This option takes effect only when there are more than one column family as otherwise the wal size is dictated by the write_buffer_size.
    
    Default: 0
    
    Parameters:
    
    maxTotalWalSize - max total wal size.
    
    Returns:
    
    the instance of the current object.
  - maxTotalWalSize
```
long maxTotalWalSize()
```
    Returns the max total write-ahead log size. Once write-ahead logs exceed this size, we will start forcing the flush of column families whose memtables are backed by the oldest live WAL file.
    
    The oldest WAL files are the ones that are causing all the space amplification.
    For example, with 15 column families, each with write_buffer_size = 128 MB max_write_buffer_number = 6 max_total_wal_size will be calculated to be [15 * 128MB * 6] * 4 = 45GB
    The RocksDB wiki has some discussion about how the WAL interacts with memtables and flushing of column families, at ...
    
    If set to 0 (default), we will dynamically choose the WAL size limit to be [sum of all write_buffer_size * max_write_buffer_number] * 4
    
    This option takes effect only when there are more than one column family as otherwise the wal size is dictated by the write_buffer_size.
    
    Default: 0
    
    If set to 0 (default), we will dynamically choose the WAL size limit to be [sum of all write_buffer_size * max_write_buffer_number] * 4
    
    Returns:
    
    max total wal size
  - setDeleteObsoleteFilesPeriodMicros
```
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
    
    Parameters:
    
    micros - the time interval in micros
    
    Returns:
    
    the instance of the current object.
  - deleteObsoleteFilesPeriodMicros
```
long deleteObsoleteFilesPeriodMicros()
```
    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
    
    Returns:
    
    the time interval in micros when obsolete files will be deleted.
  - setStatsDumpPeriodSec
```
T setStatsDumpPeriodSec(int statsDumpPeriodSec)
```
    if not zero, dump rocksdb.stats to LOG every stats_dump_period_sec Default: 600 (10 minutes)
    
    Parameters:
    
    statsDumpPeriodSec - time interval in seconds.
    
    Returns:
    
    the instance of the current object.
  - statsDumpPeriodSec
```
int statsDumpPeriodSec()
```
    If not zero, dump rocksdb.stats to LOG every stats_dump_period_sec Default: 600 (10 minutes)
    
    Returns:
    
    time interval in seconds.
  - setStatsPersistPeriodSec
```
T setStatsPersistPeriodSec(int statsPersistPeriodSec)
```
    If not zero, dump rocksdb.stats to RocksDB every statsPersistPeriodSec Default: 600
    
    Parameters:
    
    statsPersistPeriodSec - time interval in seconds.
    
    Returns:
    
    the instance of the current object.
  - statsPersistPeriodSec
```
int statsPersistPeriodSec()
```
    If not zero, dump rocksdb.stats to RocksDB every statsPersistPeriodSec
    
    Returns:
    
    time interval in seconds.
  - setStatsHistoryBufferSize
```
T setStatsHistoryBufferSize(long statsHistoryBufferSize)
```
    If not zero, periodically take stats snapshots and store in memory, the memory size for stats snapshots is capped at statsHistoryBufferSize Default: 1MB
    
    Parameters:
    
    statsHistoryBufferSize - the size of the buffer.
    
    Returns:
    
    the instance of the current object.
  - statsHistoryBufferSize
```
long statsHistoryBufferSize()
```
    If not zero, periodically take stats snapshots and store in memory, the memory size for stats snapshots is capped at statsHistoryBufferSize
    
    Returns:
    
    the size of the buffer.
  - setMaxOpenFiles
```
T setMaxOpenFiles(int maxOpenFiles)
```
    Number of open files that can be used by the DB. You may need to increase this if your database has a large working set. Value -1 means files opened are always kept open. You can estimate number of files based on target_file_size_base and target_file_size_multiplier for level-based compaction. For universal-style compaction, you can usually set it to -1. Default: -1
    
    Parameters:
    
    maxOpenFiles - the maximum number of open files.
    
    Returns:
    
    the instance of the current object.
  - maxOpenFiles
```
int maxOpenFiles()
```
    Number of open files that can be used by the DB. You may need to increase this if your database has a large working set. Value -1 means files opened are always kept open. You can estimate number of files based on target_file_size_base and target_file_size_multiplier for level-based compaction. For universal-style compaction, you can usually set it to -1. Default: -1
    
    Returns:
    
    the maximum number of open files.
  - setBytesPerSync
```
T setBytesPerSync(long bytesPerSync)
```
    Allows OS to incrementally sync files to disk while they are being written, asynchronously, in the background. Issue one request for every bytes_per_sync written. 0 turns it off. Default: 0
    
    Parameters:
    
    bytesPerSync - size in bytes
    
    Returns:
    
    the instance of the current object.
  - bytesPerSync
```
long bytesPerSync()
```
    Allows OS to incrementally sync files to disk while they are being written, asynchronously, in the background. Issue one request for every bytes_per_sync written. 0 turns it off. Default: 0
    
    Returns:
    
    size in bytes
  - setWalBytesPerSync
```
T setWalBytesPerSync(long walBytesPerSync)
```
    Same as setBytesPerSync(long) , but applies to WAL files Default: 0, turned off
    
    Parameters:
    
    walBytesPerSync - size in bytes
    
    Returns:
    
    the instance of the current object.
  - walBytesPerSync
```
long walBytesPerSync()
```
    Same as bytesPerSync() , but applies to WAL files Default: 0, turned off
    
    Returns:
    
    size in bytes
  - setStrictBytesPerSync
```
T setStrictBytesPerSync(boolean strictBytesPerSync)
```
    When true, guarantees WAL files have at most walBytesPerSync() bytes submitted for writeback at any given time, and SST files have at most bytesPerSync() bytes pending writeback at any given time. This can be used to handle cases where processing speed exceeds I/O speed during file generation, which can lead to a huge sync when the file is finished, even with bytesPerSync() / walBytesPerSync() properly configured. - If `sync_file_range` is supported it achieves this by waiting for any prior `sync_file_range`s to finish before proceeding. In this way, processing (compression, etc.) can proceed uninhibited in the gap between `sync_file_range`s, and we block only when I/O falls behind. - Otherwise the `WritableFile::Sync` method is used. Note this mechanism always blocks, thus preventing the interleaving of I/O and processing. Note: Enabling this option does not provide any additional persistence guarantees, as it may use `sync_file_range`, which does not write out metadata. Default: false
    
    Parameters:
    
    strictBytesPerSync - the bytes per sync
    
    Returns:
    
    the instance of the current object.
  - strictBytesPerSync
```
boolean strictBytesPerSync()
```
    Return the strict byte limit per sync. See setStrictBytesPerSync(boolean)
    
    Returns:
    
    the limit in bytes.
  - setCompactionReadaheadSize
```
T setCompactionReadaheadSize(long compactionReadaheadSize)
```
    If non-zero, we perform bigger reads when doing compaction. If you're running RocksDB on spinning disks, you should set this to at least 2MB. That way RocksDB's compaction is doing sequential instead of random reads. Default: 0
    
    Parameters:
    
    compactionReadaheadSize - The compaction read-ahead size
    
    Returns:
    
    the reference to the current options.
  - compactionReadaheadSize
```
long compactionReadaheadSize()
```
    If non-zero, we perform bigger reads when doing compaction. If you're running RocksDB on spinning disks, you should set this to at least 2MB. That way RocksDB's compaction is doing sequential instead of random reads. Default: 0
    
    Returns:
    
    The compaction read-ahead size

Interface MutableDBOptionsInterface<T extends MutableDBOptionsInterface<T>>

Method Summary

Method Detail

setMaxBackgroundJobs

maxBackgroundJobs

setMaxBackgroundCompactions

maxBackgroundCompactions

setAvoidFlushDuringShutdown

avoidFlushDuringShutdown

setWritableFileMaxBufferSize

writableFileMaxBufferSize

setDelayedWriteRate

delayedWriteRate

setMaxTotalWalSize

maxTotalWalSize

setDeleteObsoleteFilesPeriodMicros

deleteObsoleteFilesPeriodMicros

setStatsDumpPeriodSec

statsDumpPeriodSec

setStatsPersistPeriodSec

statsPersistPeriodSec

setStatsHistoryBufferSize

statsHistoryBufferSize

setMaxOpenFiles

maxOpenFiles

setBytesPerSync

bytesPerSync

setWalBytesPerSync

walBytesPerSync

setStrictBytesPerSync

strictBytesPerSync

setCompactionReadaheadSize

compactionReadaheadSize