https://www.aerospike.com/docs/tools/backup/asbackup.html

The asbackup utility is used to backup namespaces or sets from an Aerospike cluster to local storage. 
asbackup concurrently queries multiple nodes in the cluster. 
By default, up to 10 nodes are backed up simultaneously. 
This limit can be changed with the --parallel command line option. 
Data from each cluster node, is backed up on a partition-by-partition basis. 
If a record is created or updated after its partition was backed up, the backup will not reflect that.

默认最多同时备份10个节点 ，parallel 参数修改该值
每个集群节点的数据按分区备份，如果在备份分区之后创建或更新记录，那么备份将不会反映这一点。

While a cluster is migrating (i.e., rebalancing due to a node failure), any taken backups may not be fully consistent. 
There may be multiple copies of the same record or missing records. 
Use the --no-cluster-change option to make asbackup abort, in case it detects pending migrations.

当集群正在迁移时(节点失败导致的重新平衡）任何备份可能不完全一致，同一条记录可能有多个副本或丢失 
使用 no-cluster-change选项来执行备份中止 

When run with the --directory option, asbackup creates multiple .asb backup files in the given directory. 
The backup consists of all created files. 
Alternatively, --output-file makes asbackup store the complete backup in the given single file. 
If - is specified as the file, asbackup writes the backup to stdout. 


directory  在指定目录创建多个 .asb 备份文件
output-file 创建单个文件 

asbackup --output-file - [...] | gzip -1 [...] >backup.asb.gz

--output-file -  表示写入 stdout

asbackup --usage  显示所有命令行参数

asbackup --host 1.2.3.4 --namespace test --directory backup_2015_08_24


Estimating the Backup Size

When passing the --estimate command line option to asbackup (and skipping --directory and --output-file), 
asbackup creates a temporary test backup of 10,000 records from the namespace. 
It then outputs, based on the observed record sizes, an estimate of the average size of a record in the backup. 
In order to estimate the total size of the backup file or files, multiply this size by the number of records in the namespace and add 10% for indexes and overhead.


备份大小估算

estimate 命令行选项 (并跳过——directory和——output-file)
asbackup从名称空间创建10,000条记录的临时测试备份。
然后根据观察到的记录大小输出备份中记录的平均大小的估计值。
为了估计备份文件的总大小，将这个大小乘以名称空间中的记录数量，并加上 10% 索引开销。


Incremental Backup
Beginning from Server Version 3.12, timestamps can be specified so only records updated since timestamp X are backed up. 
An operational routine can be established to do incremental daily backups. 
Please see --modified-after option in Data Options section.

增量备份
只备份 指定时间点之后更新的记录

--host  
The host that acts as the entry point to the cluster. 
Any of the cluster nodes can be specified. The remaining cluster nodes will be automatically discovered.
充当集群入口点的主机，可以指定任何集群节点，其余的集群节点将自动被发现。

--parallel 	10   ，Maximal number of nodes to backup in parallel.  默认10
--node-list    used to backup only a subset of the cluster nodes. 只备份指定的节点列表

--set    The set to backup  默认全部
-s set1,set2...  貌似不支持备份多个set  只支持 1个

--no-cluster-change   Terminate in case of pending migrations.  集群迁移时终止备份，保证备份的一致性

--modified-after  YYYY-MM-DD_HH:MM:SS   Backup data with last-update-time after the specified date-time.
--modified-before  YYYY-MM-DD_HH:MM:SS 
--namespace    需要备份的namespace Mandatory 强制的 必选

--bin-list bin1,bin2 ...




-x or --no-bins   Only backup record metadata (digest, TTL, generation count, key).

-I or --no-indexes
-u or --no-udfs

By default, asbackup includes record data, secondary index definitions, and UDF modules.

--percent $percentage  默认备份全部 100%  Fraction of cluster records to backup. This option is useful for sampling

--priority  The level of scan concurrency on each individual node. Higher values mean faster backups. 
备份优先级 ， 越大 备份越快，可能会影响集群性能 
0 (auto), 1 (low), 2 (medium), 3 (high).


--verbose   Output considerably more information about the running backup.
输出详细信息