cfg_binary_logging_snapshots

• force_recovery
• wal_max_size
• snap_io_rate_limit
• wal_mode
• wal_dir_rescan_delay
• wal_queue_max_size
• wal_cleanup_delay
• wal_ext
• secure_erasing

Since version 1.7.4.

If force_recovery equals true, Tarantool tries to continue if there is an error while reading a snapshot file (at server instance start) or a write-ahead log file (at server instance start or when applying an update at a replica): skips invalid records, reads as much data as possible and lets the process finish with a warning. Users can prevent the error from recurring by writing to the database and executing box.snapshot().

Otherwise, Tarantool aborts recovery if there is an error while reading.

Type: boolean

Default: false

Environment variable: TT_FORCE_RECOVERY

Dynamic: no

Since version 1.7.4.

The maximum number of bytes in a single write-ahead log file. When a request would cause an .xlog file to become larger than wal_max_size, Tarantool creates a new WAL file.

Type: integer

Default: 268435456 (256 * 1024 * 1024) bytes

Environment variable: TT_WAL_MAX_SIZE

Dynamic: no

Since version 1.4.9.

Reduce the throttling effect of box.snapshot() on INSERT/UPDATE/DELETE performance by setting a limit on how many megabytes per second it can write to disk. The same can be achieved by splitting wal_dir and memtx_dir locations and moving snapshots to a separate disk. The limit also affects what box.stat.vinyl().regulator may show for the write rate of dumps to .run and .index files.

Type: float

Default: null

Environment variable: TT_SNAP_IO_RATE_LIMIT

Dynamic: yes

Since version 1.6.2.

Specify fiber-WAL-disk synchronization mode as:

• none: write-ahead log is not maintained. A node with wal_mode set to none can't be a replication master.
• write: fibers wait for their data to be written to the write-ahead log (no fsync(2)).
• fsync: fibers wait for their data, fsync(2) follows each write(2).

Type: string

Default: "write"

Environment variable: TT_WAL_MODE

Dynamic: no

Since version 1.6.2.

The time interval in seconds between periodic scans of the write-ahead-log file directory, when checking for changes to write-ahead-log files for the sake of replication or hot standby.

Type: float

Default: 2

Environment variable: TT_WAL_DIR_RESCAN_DELAY

Dynamic: no

Since version 2.8.1.

The size of the queue (in bytes) used by a replica to submit new transactions to a write-ahead log (WAL). This option helps limit the rate at which a replica submits transactions to the WAL. Limiting the queue size might be useful when a replica is trying to sync with a master and reads new transactions faster than writing them to the WAL.

Type: number

Default: 16777216 bytes

Environment variable: TT_WAL_QUEUE_MAX_SIZE

Dynamic: yes

Since version 2.6.3.

The delay in seconds used to prevent the Tarantool garbage collector from immediately removing write-ahead log files after a node restart. This delay eliminates possible erroneous situations when the master deletes WALs needed by replicas after restart. As a consequence, replicas sync with the master faster after its restart and don't need to download all the data again. Once all the nodes in the replica set are up and running, a scheduled garbage collection is started again even if wal_cleanup_delay has not expired.

Type: number

Default: 14400 seconds

Environment variable: TT_WAL_CLEANUP_DELAY

Dynamic: yes

Since version 2.11.0.

(Enterprise Edition only) Allows you to add auxiliary information to each write-ahead log record. For example, you can enable storing an old and new tuple for each CRUD operation performed. This information might be helpful for implementing a CDC (Change Data Capture) utility that transforms a data replication stream.

You can enable storing old and new tuples as follows:

• Set the old and new options to true to store old and new tuples in a write-ahead log for all spaces.

   
  box.cfg {    wal_ext = { old = true, new = true }}

• To adjust these options for specific spaces, use the spaces option.

   
  box.cfg {    wal_ext = {        old = true, new = true,        spaces = {            space1 = { old = false },            space2 = { new = false }        }    }}

  The configuration for specific spaces has priority over the global configuration, so only new tuples are added to the log for space1 and only old tuples for space2.

Note that records with additional fields are replicated as follows:

• If a replica doesn't support the extended format configured on a master, auxiliary fields are skipped.
• If a replica and master have different configurations for WAL records, the master's configuration is ignored.

Type: map

Default: nil

Environment variable: TT_WAL_EXT

Dynamic: yes

Since version 3.0.0.

(Enterprise Edition only) If true, forces Tarantool to overwrite a data file a few times before deletion to render recovery of a deleted file impossible. The option applies to both .xlog and .snap files as well as Vinyl data files.

Type: boolean

Default: false

Environment variable: TT_SECURE_ERASING

Dynamic: yes