（進階篇）Redis6.2.0 集群 主從復制_原理剖析_02
2022-09-06 22:44:50

* Ready to accept connections # 準備就緒等待鏈接
* Replica 1xxx.xxx.xxx.101:6379 asks for synchronization
  # 102節(jié)點向主節(jié)點發(fā)起了一個全量resync 的請求
* Full resync requested by replica 1xxx.xxx.xxx.101:6379
  # 主節(jié)點創(chuàng)建緩沖區(qū)，
* Replication backlog created, my new replication IDs are 'b1f446c9ea7c0d5e95c8c47f31b000000000000000000000000000'
  # 通過BGSAVE 將數(shù)據(jù)寫入磁盤，生成rdb快照，發(fā)給子節(jié)點
* Starting BGSAVE for SYNC with target: disk
* Background saving started by pid 11978
* DB saved on disk
  # 通過copy-on-write的方式將4m數(shù)據(jù)寫入磁盤
* RDB: 6 MB of memory used by copy-on-write
* Background saving terminated with success
  # 101 節(jié)點的復制結束了 子節(jié)點加載rdb快照文件讀取數(shù)據(jù)
* Synchronization with replica 1xxx.xxx.xxx.101:6379 succeeded
* Replica 1xxx.xxx.xxx.102:6379 asks for synchronization
* Full resync requested by replica 1xxx.xxx.xxx.102:6379
* Starting BGSAVE for SYNC with target: disk
* Background saving started by pid 11979
* DB saved on disk
* RDB: 4 MB of memory used by copy-on-write
* Background saving terminated with success
* Synchronization with replica 1xxx.xxx.xxx.102:6379 succeeded
# Disconnecting timedout replica: 1xxx.xxx.xxx.101:6379
# Connection with replica 1xxx.xxx.xxx.101:6379 lost.
# Disconnecting timedout replica: 1xxx.xxx.xxx.102:6379

[root@bigdata01 bin]# /usr/local/redis/bin/redis-cli -a 123456
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
127.0.0.1:6379> info replication
# Replication
role:master # 角色主節(jié)點
connected_slaves:2 #它所連接到的從節(jié)點的數(shù)量
# 從節(jié)點ip地址、 端口、狀態(tài)：在線 當前從節(jié)點讀取命令的偏移量 延遲時間：單位:秒
#offset指的是從節(jié)點已經(jīng)復制的命令偏移量是266
# 這里的offset=master_repl_offset說明主從偏移量是一致的
slave0:ip=1xxx.xxx.xxx.101,port=6379,state=online,offset=266,lag=1 #當前連接從01 slave節(jié)點信息
slave1:ip=1xxx.xxx.xxx.102,port=6379,state=online,offset=266,lag=1 #當前連接從02 slave節(jié)點信息
master_failover_state:no-failover
# 主從的id
master_replid:b1f446c9ea7c0d5e95c8c47f31bb007cea158ce8
# 主從發(fā)生變化之后id
master_replid2:0000000000000000000000000000000000000000
# 主節(jié)點會把所有的命令轉換成子字節(jié)。寫到隊里額里面，最終寫入的值就是master_repl_offset
# 主節(jié)點已寫入的命令偏移量是266
master_repl_offset:266
# 判斷是否全量復制的標識
second_repl_offset:-1

# 2.8之后 緩沖區(qū)
repl_backlog_active:1 # 是否開啟緩沖區(qū) 1-開啟 0-關閉
repl_backlog_size:1048576 # 緩沖區(qū)大小 1m，可以調控
repl_backlog_first_byte_offset:1 # 從偏移量為1開始寫入
repl_backlog_histlen:266 # 當前緩存沖區(qū)長度
127.0.0.1:6379>

[root@bigdata02 ~]# /usr/local/redis/bin/redis-cli -a 123456
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
127.0.0.1:6379> info replication
# Replication
 # 角色
role:slave
# 主節(jié)點ip
master_host:1xxx.xxx.xxx.100
# 主節(jié)點端口
master_port:6379
# 主節(jié)點當前狀態(tài)
master_link_status:up
# 主從復制最后一次 4秒之前
master_last_io_seconds_ago:4
# 現(xiàn)在主從同步狀態(tài) 0-未同步 1-正在同步
master_sync_in_progress:0
# 從節(jié)點復制的偏移量
slave_repl_offset:3xxx
# 從節(jié)點在選舉時，成為主節(jié)點的權重優(yōu)先級，這個參數(shù)越大，晉升主節(jié)點的優(yōu)先級越高
slave_priority:100
# 從節(jié)點只讀模式是否開啟 1-開啟 0-未開啟
slave_read_only:1
# 從節(jié)點連接從節(jié)點數(shù)量
connected_slaves:0
master_failover_state:no-failover
# 連接主節(jié)點的id
#當前主節(jié)點宕機后master_replid會變成一個信心的，master_replid2存儲老的主節(jié)點master_replid
master_replid:b1f446c9ea7c0d5e95c8c47f31bb007cea158ce8
master_replid2:0000000000000000000000000000000000000000
# 主節(jié)點寫入的偏移量
master_repl_offset:3xxx
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1
repl_backlog_histlen:3xxx
127.0.0.1:6379>