新接手的四套庫MySQL庫，採用主從結構。之前配置的夥計備庫的bin log 日誌全部是打開狀態。運維人員反映，空間告警幾次。均手動上去處理。
備庫開啓了bin log 也影響備庫的性能，雖然這四套MySQL庫的壓力不大，但是本着優化的態度，還是對這四套庫做一次徹底的清楚。
1. 查看備庫當前的bin log：
show binary logs;
直接刷出了七百多個bin - log。從上線之初到現在一年時間， 只有1T的bin log
2. 查看備庫的slave 運行狀態
show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 10.180.213.58
Master_User: rep581
Master_Port: 3301
Connect_Retry: 60
Master_Log_File: mysql-bin.000266
Read_Master_Log_Pos: 429863077
Relay_Log_File: mysql-relay-bin.000780
Relay_Log_Pos: 429863287
Relay_Master_Log_File: mysql-bin.000266
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 429863077
Relay_Log_Space: 429863578
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 581
Master_UUID: d4d049b3-7151-11e5-972f-000af77f26d8
Master_Info_File: /mysqldata/mysql2/dat/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set: d4d049b3-7151-11e5-972f-000af77f26d8:1-395318788
Executed_Gtid_Set: d41f98d3-7151-11e5-972f-000af77f26d8:1-471129318,
d4d049b3-7151-11e5-972f-000af77f26d8:1-395318788
Auto_Position: 1
1 row in set (0.00 sec)
從上面四個指標可以看出備庫運行正常，且沒有任何延遲。因此可以開始手動清理
3. 手動清理，清理原則： 手動清理五天以前的bin log
PURGE MASTER LOGS BEFORE DATE_SUB(CURRENT_DATE, INTERVAL 5 DAY);
持續一段時間以後，binglog手動清理完畢。
4. 關閉slave備庫bin log。註銷備庫my.cnf一下參數：
#log-bin = /mysqldata/mysql2/bin/mysql-bin
#sync_binlog = 1
#binlog_cache_size = 4M
#max_binlog_cache_size = 8M
#max_binlog_size = 1024M
最後需要重啓該庫才能夠生效！