【文件属性】：
文件名称：replican:基于 Spanner 的复制
文件大小：47KB
文件格式：ZIP
更新时间：2021-06-25 21:48:52
Java
复制品
rsync like replication implementation
操作
创建一个文件，
if (size > 0)
tailed file content will be created
else
create an empty file
reply the checkpoint for ledger
删除一个文件，
delete the file from replican (remote) and clear up ledger
更新文件，（目前仅追加，用于日志复制）
delta content will be created from ledgered checkpoints
sent to remote
replicated on remote
updated checkpoints will be ledgered
命