J3: redis master-slave replication

Master slave consistency

AOF and RDB It can reduce data loss , But reducing service disruption requires adding redundant copies

Master slave synchronization for the first time

Master slave replication uses RDB no need AOF Because AOF File size （ There will also be one Key Repetitive operation ）,ROB Is a compressed binary , The file is small , Fast execution
from :replicaof Lord ip Lord port

If there are many slave libraries , If the host synchronization is required , It will affect the performance of the main library , So there is Lord - from - from Pattern

After the master-slave network is disconnected , The master-slave library will adopt the method of incremental replication , Used repl_backlog_buffer buffer

• After master-slave disconnection , The operation of the main library will write replication buffer, Will also write repl_backlog_buffer
• repl_backlog_buffer The main library will record the location of its own writing , The read location will be recorded from the Library .
• The offset written by the main library is master_repl_offset, The offset copied from the library is slave_repl_offset

• After recovering from the Library , It will be sent to the main library psync, hold slave_repl_offset Send to main library , The main database will judge the difference between the two direct
• 
• You can adjust repl_backlog_size Size ( Default 1M), Increase the size of the buffer