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Parameters and Settings

Enable/Disable the serverless mode​

serverless​

WeSQL, by default, uses object storage as its persistent storage medium. This includes persisting the binlog to object storage, creating consistent snapshots and saving them to object storage, and persisting SmartEngine extent data to object storage. However, to support environments where object storage is unavailable, or to compare the performance between object storage and local disk, WeSQL also supports using local disk as the persistent storage medium. In such cases, serverless mode must be disabled.

The serverless mode can be disabled either via the server command option:

mysqld --serverless=false

or by modifying the option file (my.cnf):

serverless=false

Object Storage Settings​

WeSQL persists data to object storage. This section covers the configuration parameters related to object storage.

objectstore_provider​

The object storage provider setting. Currently supported values are aws and local, and this parameter is mandatory.

The local option simulates object storage using the local file system and is intended for testing and development purposes only.

note

When objectstore_provider is set to local, the serverless mode must be enabled. This behavior is different from disabling serverless mode, even though in both configurations the local disk is used.

Example:

objectstore_provider=aws

objectstore_region​

The region where the object storage is located. This parameter is Required.

Example:

objectstore_region=cn-northwest-1

objectstore_endpoint​

The endpoint of the object storage. This allows access to the object storage via the specified endpoint.

objectstore_use_https​

Specifies whether to use the HTTPS protocol for accessing object storage. The default value is false.

Example:

objectstore_use_https=true

objectstore_bucket​

The bucket in the object storage where all persistent data of the WeSQL instance will be stored. Each bucket can only be used by one instance, and this parameter is Required.

Example:

objectstore_bucket=wesql-cluster-1

cluster_objectstore_id​

The data directory identifier under the object storage bucket that stores all persistent data of the WeSQL instance. To ensure the uniqueness of data directory identifiers for different instances under the bucket, it is recommended to set option value as UUID.

Example:

cluster_objectstore_id=FD2D88FB-7994-4318-AD3F-2E37ADF52DBC

> uuidgen 
FD2D88FB-7994-4318-AD3F-2E37ADF52DBC

Consistent Snapshot Settings​

consistent_snapshot_persistent_on_objectstore​

Indicates whether to enable consistent snapshots, default is true. Consistent snapshots will be periodically generated and persisted to object storage. Consistent snapshots should be disabled for Logger nodes.

Example:

consistent_snapshot_persistent_on_objectstore=false

consistent_snapshot_archive_dir​

The local temporary archive path for consistent snapshot objects. This directory must be created before starting the instance, and it must not be a subdirectory of the datadir. The default value is null, which will automatically use MySQL's tmp directory (--tmpdir) as the archive_dir.

Example:

consistent_snapshot_archive_dir=/u01/wesql_archive_dir

consistent_snapshot_archive_period​

The frequency, in seconds, at which a consistent snapshot is generated. The default value is 600 seconds (10 minutes). A consistent snapshot is created at every cycle. Additionally, a consistent snapshot is generated after the system starts up and before shuts down gracefully.

Example:

consistent_snapshot_archive_period=1800

consistent_snapshot_expire_auto_purge​

Indicates whether to enable the automatic cleanup of expired consistent snapshots stored in object storage. The default value is true. Consistent snapshots will be cleaned up when the creation time plus 'consistent_snapshot_expire_seconds' exceeds the current time.

Example:

consistent_snapshot_expire_auto_purge=true

consistent_snapshot_expire_seconds​

The expiration period, in seconds, for consistent snapshots stored in object storage. The default value is 0, meaning only the latest consistent snapshot is retained, and older snapshots are automatically purged. If you want to retain historical consistent snapshots, you can set a specific period in seconds to keep them for a defined time. This setting can be used for Point-in-Time Recovery (PITR).

Example:

consistent_snapshot_expire_seconds=2592000

consistent_snapshot_innodb_tar_mode​

In what format is the InnoDB data of a consistent snapshot persisted to object storage.

'TAR' indicates that InnoDB data is first packaged using tar locally before being persisted. 'TAR_AND_COMPRESS' indicates that InnoDB data is first compressed and then packaged using tar before being persisted. 'OFF' indicates that InnoDB data is directly persisted by directory. The defaut value is 'OFF'.

consistent_snapshot_innodb_tar_mode=TAR

consistent_snapshot_smartengine_tar_mode​

In what format is the SmartEngine data of a consistent snapshot persisted to object storage.

'TAR' indicates that SmartEngine data is first packaged using tar locally before being persisted. 'TAR_AND_COMPRESS' indicates that SmartEngine data is first compressed and then packaged using tar before being persisted. 'OFF' indicates that SmartEngine data is directly persisted by directory. The defaut value is 'OFF'.

consistent_snapshot_smartengine_tar_mode=TAR

Binlog Archive Settings​

binlog_archive​

Indicates whether to enable binlog persistent, default is true. Binlog will be periodically persisted to object storage.

binlog_archive=false

binlog_archive_dir​

The local temporary archive path for binlog objects. This directory must be created before starting the instance, and it must not be a subdirectory of the datadir. The default value is null, which will automatically use MySQL's tmp directory (--tmpdir) as the archive_dir.

Example:

binlog_archive_dir=/u01/wesql_archive_dir

binlog_archive_slice_max_size​

The binlog object size when uploaded to object storage, with a default value of 4MB. During the binlog persistence process, events are batched and written to the local cache. Once the size limit defined by this parameter is reached, these events are packaged and uploaded to object storage as a binlog slice object.

Example:

binlog_archive_slice_max_size=1048576

For example, the binlog file binlog.000001 would have the following slice objects:

binlog.000001.00000000000000000002.0004048843
binlog.000001.00000000000000000002.0009345154
binlog.000001.00000000000000000002.0010137258

binlog_archive_period​

The minimum time period for binlog persistence, during which binlog events must be persisted even if the locally cached binlog events have not reached 'binlog_archive_slice_max_size'.The goal is to achieve near real-time persistence, even if the binlog is persisted to object storage in batches. The default value is 3 seconds.

Example:

binlog_archive_period=3

binlog_archive_expire_auto_purge​

Indicates whether to enable the automatic cleanup of expired binlog objects stored in object storage. The default value is true. Binlog objects will be cleaned up when the creation time plus 'binlog_archive_expire_seconds' exceeds the current time.

Example:

binlog_archive_expire_auto_purge=true

binlog_archive_expire_seconds​

The expiration period, in seconds, for binlog objects stored in object storage. The default value is 2592000 seconds (30 days). The value of binlog_archive_expire_seconds should be greater than consistent_snapshot_expire_seconds. Otherwise, even if a binlog is marked as expired, it cannot be purged as long as it is still referenced by a consistent snapshot.

Example:

binlog_archive_expire_seconds=2592000

Raft Group Settings(TODO: the description)​

raft-replication-cluster-id​

Specifies the Raft group cluster ID.

raft-replication-cluster-info​

Defines the Raft group members and their respective addresses (this is logger node 2 in the cluster).

--raft-replication-cluster-info='192.168.0.2:13006;192.168.0.3:13007;192.168.0.4:13008@2'

raft_replication_auto_leader_transfer​

Allows automatic leader transfer in the Raft group.

raft_replication_log_type_node​

Specifies that this node is a logger node in the Raft group.

raft_replication_election_timeout​

raft election timeout.

raft_replication_heartbeat_thread_cnt​

Number of raft heartbeat thread.

raft_replication_io_thread_cnt​

Number of raft IO thread.

raft_replication_worker_thread_cnt​

Number of raft worker thread.

raft_replication_large_trx​

raft large trx or not.

raft_replication_max_log_size​

Max one log size. (default: 20M)

raft_replication_large_event_split_size​

Split size for large event, dangerous to change this variable.

raft_replication_log_cache_size​

Max cached logs size.

raft_replication_log_level​

raft log level.

raft_replication_new_follower_threshold​

Max delay index to allow a learner becomes a follower.

raft_replication_pipelining_timeout​

The timeout the raft server cache the log (milliseconds).

raft_replication_send_timeout​

raft send packet timeout.

raft_replication_configure_change_timeout​

raft configure change timeout (ms). Default 1 min.

raft_replication_force_change_meta​

raft cluster force to change meta.

raft_replication_force_single_mode​

raft cluster force to use single mode.

raft_replication_learner_node​

raft cluster learner node type.

raft_replication_learner_timeout​

raft learner connection timeout.

Smartengine Settings(TODO)​

table_on_objectstore​