2.4 KiB
Durability Configuration
Global Configuration
There are global configuration values for durability, which can be adjusted by specifying the following configuration options:
@startDocuBlock databaseWaitForSync
@startDocuBlock databaseForceSyncProperties
@startDocuBlock WalLogfileSyncInterval
--rocksdb.sync-interval
The interval (in milliseconds) that ArangoDB will use to automatically synchronize data in RocksDB's write-ahead logs to disk. Automatic syncs will only be performed for not-yet synchronized data, and only for operations that have been executed without the waitForSync attribute.
Per-collection configuration
You can also configure the durability behavior on a per-collection basis. Use the ArangoDB shell to change these properties.
@startDocuBlock collectionProperties
Per-operation configuration
Many data-modification operations and also ArangoDB's transactions allow to specify a waitForSync attribute, which when set ensures the operation data has been synchronized to disk when the operation returns.
Disk-Usage Configuration (MMFiles engine)
The amount of disk space used by the MMFiles engine is determined by a few configuration options.
Global Configuration
The total amount of disk storage required by the MMFiles engine is determined by the size of the write-ahead logfiles plus the sizes of the collection journals and datafiles.
There are the following options for configuring the number and sizes of the write-ahead logfiles:
@startDocuBlock WalLogfileReserveLogfiles
@startDocuBlock WalLogfileHistoricLogfiles
@startDocuBlock WalLogfileSize
@startDocuBlock WalLogfileAllowOversizeEntries
When data gets copied from the write-ahead logfiles into the journals or datafiles of collections, files will be created on the collection level. How big these files are is determined by the following global configuration value:
@startDocuBlock databaseMaximalJournalSize
Per-collection configuration
The journal size can also be adjusted on a per-collection level using the collection's properties method.