redis数据同步之redis-shake
redis-shake简介
redis-shake是阿里开源的用于redis数据同步的工具，基本功能有：
- 恢复restore：将RDB文件恢复到目的redis数据库。
- 备份dump：将源redis的全量数据通过RDB文件备份起来。
- 解析decode：对RDB文件进行读取，并以json格式解析存储。
- 同步sync：支持源redis和目的redis的数据同步，支持全量和增量数据的迁移，支持从云下到阿里云云上的同步，也支持云下到云下不同环境的同步，支持单节点、主从版、集群版之间的互相同步。需要注意的是，如果源端是集群版，可以启动一个RedisShake，从不同的db结点进行拉取，同时源端不能开启move slot功能；对于目的端，如果是集群版，写入可以是1个或者多个db结点。
- 同步rump：支持源redis和目的redis的数据同步，仅支持全量的迁移。采用scan和restore命令进行迁移，支持不同云厂商不同redis版本的迁移。
基本原理
如果源端是集群模式，只需要启动一个redis-shake进行拉取，同时不能开启源端的move slot操作。如果目的端是集群模式，可以写入到一个结点，然后再进行slot的迁移，当然也可以多对多写入。
目前，redis-shake到目的端采用单链路实现，对于正常情况下，这不会成为瓶颈，但对于极端情况，qps比较大的时候，此部分性能可能成为瓶颈。另外，redis-shake到目的端的数据同步采用异步的方式，读写分离在2个线程操作，降低因为网络时延带来的同步性能下降。
全量同步阶段并发执行，增量同步阶段异步执行，能够达到毫秒级别延迟（取决于网络延迟）。同时，对大key同步进行分批拉取，优化同步性能。
用户可以通过我们提供的restful拉取metric来对redis-shake进行实时监控：curl 127.0.0.1:9320/metric。
支持
- 支持2.8-5.0版本的同步。
- 支持codis。
- 支持云下到云上，云上到云上，云上到云下（阿里云目前支持主从版），其他云到阿里云等链路，帮助用户灵活构建混合云场景。
使用
1、直接下载二进制包这里
2、修改配置文件
]# tar -zxf release-v2.1.0-20210819.tar.gz
]# cd redis-shake
]# ll
total 41252
-rw-r--r-- 1 502 games 12542 Aug 25 17:50 redis-shake.conf
-rwxr-xr-x 1 502 games 11853504 Aug 19 10:11 redis-shake.darwin
-rwxr-xr-x 1 502 games 11918954 Aug 19 10:11 redis-shake.linux
-rwxr-xr-x 1 502 games 12227584 Aug 19 10:11 redis-shake.windows
修改redis-shake.conf，我的环境是从两套redis主从之间同步数据，配置文件如下（删减过部分默认配置）
conf.version = 1
id = redis-shake
log.file = /opt/redis-shake/redis-shake.log
log.level = info
pid_path =
system_profile = 9310
http_profile = 9320
parallel = 32
source.type = standalone
source.address = 10.26.31.172:6379
source.password_raw =
source.auth_type = auth
source.tls_enable = false
source.rdb.input =
source.rdb.parallel = 0
source.rdb.special_cloud =
target.type = standalone
target.address = 10.26.29.235:6389
target.password_raw =
target.auth_type = auth
target.db = 0
key_exists = rewrite
filter.db.whitelist = 0
说明：
a、主要需要修改源redis和目的redis的信息
b、当源和目的有重复 key 时是否进行覆写, 可选值:
1. rewrite: 源端覆盖目的端
2. none: 一旦发生进程直接退出
3. ignore: 保留目的端key，忽略源端的同步 key. 该值在 rump 模式下不会生效.
key_exists = rewrite
c、指定的db被通过，比如0;5;10将会使db0, db5, db10通过, 其他的被过滤
filter.db.whitelist = 0
更多详细参数参见官网
3、启动
用户配置完配置文件，然后以不同的模式启动即可：
./redis-shake -conf=redis-shake.conf -type=sync &
然后可以查看配置的日子路径，查看服务运行状态,一般正常情况下日志如下
2021/08/25 17:19:54 [WARN] source.auth_type[auth] != auth
2021/08/25 17:19:54 [WARN] target.auth_type[auth] != auth
2021/08/25 17:19:54 [INFO] input password is empty, skip auth address[10.26.29.235:6389] with type[auth].
2021/08/25 17:19:54 [INFO] input password is empty, skip auth address[10.26.31.172:6379] with type[auth].
2021/08/25 17:19:54 [INFO] input password is empty, skip auth address[10.26.31.172:6379] with type[auth].
2021/08/25 17:19:54 [INFO] source rdb[10.26.31.172:6379] checksum[yes]
2021/08/25 17:19:54 [WARN]
______________________________
\ \ _ ______ |
\ \ / \___-=O'/|O'/__|
\ RedisShake, here we go !! \_______\ / | / )
/ / '/-==__ _/__|/__=-| -GM
/ Alibaba Cloud / * \ | |
/ / (o)
------------------------------
if you have any problem, please visit https://github.com/alibaba/RedisShake/wiki/FAQ
2021/08/25 17:19:54 [INFO] redis-shake configuration: {"ConfVersion":1,"Id":"redis-shake","LogFile":"/opt/redis-shake/redis-shake.log","LogLevel":"info","SystemProfile":9310,"HttpProfile":9320,"Parallel":32,"SourceType":"standalone","SourceAddress":"10.26.31.172:6379","SourcePasswordRaw":"***","SourcePasswordEncoding":"***","SourceAuthType":"auth","SourceTLSEnable":false,"SourceRdbInput":[],"SourceRdbParallel":1,"SourceRdbSpecialCloud":"","TargetAddress":"10.26.29.235:6389","TargetPasswordRaw":"***","TargetPasswordEncoding":"***","TargetDBString":"0","TargetDBMapString":"","TargetAuthType":"auth","TargetType":"standalone","TargetTLSEnable":false,"TargetRdbOutput":"local_dump","TargetVersion":"6.0.9","FakeTime":"","KeyExists":"none","FilterDBWhitelist":[],"FilterDBBlacklist":[],"FilterKeyWhitelist":[],"FilterKeyBlacklist":[],"FilterSlot":[],"FilterLua":false,"BigKeyThreshold":524288000,"Metric":true,"MetricPrintLog":false,"SenderSize":104857600,"SenderCount":4095,"SenderDelayChannelSize":65535,"KeepAlive":0,"PidPath":"","ScanKeyNumber":50,"ScanSpecialCloud":"","ScanKeyFile":"","Qps":200000,"ResumeFromBreakPoint":false,"Psync":true,"NCpu":0,"HeartbeatUrl":"","HeartbeatInterval":10,"HeartbeatExternal":"","HeartbeatNetworkInterface":"","ReplaceHashTag":false,"ExtraInfo":false,"SockFileName":"","SockFileSize":0,"FilterKey":null,"FilterDB":"","Rewrite":false,"SourceAddressList":["10.26.31.172:6379"],"TargetAddressList":["10.26.29.235:6389"],"SourceVersion":"4.0.11","HeartbeatIp":"127.0.0.1","ShiftTime":0,"TargetReplace":false,"TargetDB":0,"Version":"tidy-code-for-release,ba0f3e1aa6e0956bfa2973a4c894cbc1a8d3d732,go1.16.7,2021-08-19_10:11:39","Type":"sync","TargetDBMap":null}
2021/08/25 17:19:54 [INFO] DbSyncer[0] starts syncing data from 10.26.31.172:6379 to [10.26.29.235:6389] with http[9321], enableResumeFromBreakPoint[false], slot boundary[-1, -1]
2021/08/25 17:19:54 [INFO] input password is empty, skip auth address[10.26.31.172:6379] with type[auth].
2021/08/25 17:19:54 [INFO] DbSyncer[0] psync connect '10.26.31.172:6379' with auth type[auth] OK!
2021/08/25 17:19:54 [INFO] DbSyncer[0] psync send listening port[9320] OK!
2021/08/25 17:19:54 [INFO] DbSyncer[0] try to send 'psync' command: run-id[?], offset[-1]
2021/08/25 17:22:30 [INFO] Event:FullSyncStart Id:redis-shake
2021/08/25 17:22:30 [INFO] DbSyncer[0] psync runid = 52aa8214f9f8238c32f172badbb4f4ea325c6cc4, offset = 9452286340998, fullsync
2021/08/25 17:22:30 [INFO] DbSyncer[0] +
2021/08/25 17:22:31 [INFO] DbSyncer[0] -
2021/08/25 17:22:31 [INFO] DbSyncer[0] +
日志信息
同步分为三个阶段：
1、等待源端save rdb完毕，日志如下
2021/08/25 17:22:30 [INFO] DbSyncer[0] +
2021/08/25 17:22:31 [INFO] DbSyncer[0] -
2021/08/25 17:22:31 [INFO] DbSyncer[0] +
2、全量同步阶段，显示百分比
2021/08/25 17:28:09 [INFO] DbSyncer[0] total = 9.06GB - 3.82MB [ 0%] entry=56515
2021/08/25 17:28:10 [INFO] DbSyncer[0] total = 9.06GB - 7.67MB [ 0%] entry=114522
2021/08/25 17:28:11 [INFO] DbSyncer[0] total = 9.06GB - 11.28MB [ 0%] entry=168877
3、增量同步，出现字样sync rdb done后，当前dbSyncer进入增量同步
2021/08/26 09:40:58 [INFO] DbSyncer[0] sync: +forwardCommands=3 +filterCommands=3 +writeBytes=33
2021/08/26 09:40:59 [INFO] DbSyncer[0] sync: +forwardCommands=2 +filterCommands=0 +writeBytes=23
2021/08/26 09:41:00 [INFO] DbSyncer[0] sync: +forwardCommands=1 +filterCommands=3 +writeBytes=11
注意事项
1、如果目标库的数据逐出策略（maxmemory-policy）配置为noeviction以外的值，可能导致目标库的数据与源库不一致。关于数据逐出策略详情，请参见Redis数据逐出策略介绍。
2、如果源库中的某些Key使用了过期（expire）机制，由于可能存在Key已过期但未被及时删除的情形，所以在目标库中查看（如通过info命令）到的Key数量会比源库的Key数量少。
