数据库复制
| Redis 企业软件 |
|---|
数据库复制有助于确保高可用性。 启用复制后，您的数据集将复制到副本分片。 它与主分片不断同步。如果主 分片失败，将发生自动故障转移，并提升副本分片。也就是说，它将成为新的主分片。
当旧的主分片恢复时，它会变为 新主分片的副本分片。此自动故障转移机制 保证以最小的中断提供数据。
您可以通过以下方式调整高可用性配置：
- 机架/区域 感知 - 当使用机架区域感知时，额外的逻辑可确保主分片和副本分片永远不会共享同一个机架，从而确保即使在丢失整个机架的情况下也能保持可用性。
- 副本分片的高可用性 – 高可用性时 对于使用副本分片，副本分片将在节点故障转移时自动迁移以保持高可用性。
Auto Tiering 复制注意事项
我们建议您使用rladmin.这是因为复制速度可能相对较慢
启用自动分层的数据库可能发生的时间。在一些
的情况下，如果未设置顺序复制，则可能会耗尽内存。
虽然它不会导致 primary shards，则复制到副本分片的时间可能不会成功 由于主 Broker 和 Multiple 上存在高写入速率流量 复制。
以下内容rladmin命令设置符合条件的主分片数
从同一集群节点复制，以及副本数量
同一集群节点上的分片，该分片可以在
任何给定的时间。
建议的顺序复制配置有两种，即：
rladmin tune cluster max_redis_forks 1 max_slave_full_syncs 1
Note:
This means that at any given time,
only one primary and one replica can be part of a full sync replication process.
Database replication backlog
Redis databases that use replication for high availability maintain a replication backlog (per shard) to synchronize the primary and replica shards of a database.
By default, the replication backlog is set to one percent (1%) of the database size divided by the database number of shards and ranges between 1MB to 250MB per shard.
Use the rladmin and the crdb-cli utilities to control the size of the replication backlog. You can set it to auto or set a specific size.
The syntax varies between regular and Active-Active databases.
For a regular Redis database:
rladmin tune db <db:id | name> repl_backlog <Backlog size in MB | 'auto'>
For an Active-Active database:
crdb-cli crdb update --crdb-guid <crdb_guid> --default-db-config "{\"repl_backlog_size\": <size in MB | 'auto'>}"
Active-Active replication backlog
In addition to the database replication backlog, Active-Active databases maintain a backlog (per shard) to synchronize the database instances between clusters.
By default, the Active-Active replication backlog is set to one percent (1%) of the database size divided by the database number of shards, and ranges between 1MB to 250MB per shard.
Use the crdb-cli utility to control the size of the CRDT replication backlog. You can set it to auto or set a specific size:
crdb-cli crdb update --crdb-guid <crdb_guid> --default-db-config "{\"crdt_repl_backlog_size\": <size in MB | 'auto'>}"
For Redis Software versions earlier than 6.0.20:
The replication backlog and the CRDT replication backlog defaults are set to 1MB and cannot be set dynamically with 'auto' mode.
To control the size of the replication log, use rladmin to tune the local database instance in each cluster.
rladmin tune db <db:id | name> repl_backlog <Backlog size in MB (or if ending with bytes, KB or GB, in the respective unit)>
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