MariaDB复制和pt-table-checksum

复制相关的文件:
master.info:用于保存从服务器链接主服务器所需要的信息,每行一个值
relay-log.info:文本文件,保存复制位置,包括二进制日志和中继日志的文件及位置

为了复制的安全性:

sync_master_info = 1
sync_relay_log = 1
sync_relay_log_info = 1

基于行基于语句复制:
基于语句:
数据量小,易于查看,实用性较强
有些语句也无法做精确复制:无法对使用了触发器,存储过程等代码的应用实现精确复制;

基于行:
能够精确完成有着触发器,存储等代码场景中的复制,能完成几乎对所有的复制功能,并且较少的cpu占用率
但是,无法判断执行了什么样的sql语句

评估主从服务表中数据是否一致:pt-table-checksum
通常次命令会在主服务器运行,检查从服务器是否一致,如果不一致,则手动同步
1,重新备份主服务器数据,并且在从服务器导入数据
2,pt-table-sync同步,高效同步,但是在数据量大时候,相当消耗时间

用法举例:

假设10.55.55.55是主库,10.73.73.73是它的从库,端口在3306。

  1. 先校验:

    PTDEBUG=1 ./pt-table-checksum --user=user --password=pass --host=10.55.55.55 --port=3306 --databases=elink --tables=my_cms_10 --recursion-method=processlist

  2. 根据校验结果,只修复10.73.73.73从库与主库不一致的地方:

    PTDEBUG=1 ./pt-table-sync --execute --replicate percona.checksums --sync-to-master h=10.73.73.73,P=3306,u=user,p=pass

  3. 修复后,再重新校验一次。执行第一步的语句即可。

  4. 检查修复结果: 登陆到10.73.73.73,执行如下sql语句返回若为空,则说明修复成功:

    select * from percona.checksums where master_cnt <> this_cnt OR master_crc <> this_crc OR ISNULL(master_crc) <> ISNULL(this_crc)

为了提高复制时的数据安全性,在主服务器上设定(对系统性能有严重的损耗,一般设置为2):

sync_binlog = 1
innodb_flush_log_at_trx_commit = 1

设置为1,对系统性能有严重的损耗,;一般设置为2,如果为2,则主服务器崩溃依然有可能导致从服务器无法获取到全部的二进制日志事件

***从服务器意崩溃时,使用pt-slave-start命令来启动
***主服务器崩溃导致二进制日志没写完,从则需要忽略或者使用pt-table重新同步
在从使用如下参数忽略:sql_slave_skip_counter = 1
如:sql_slave_skip_counter 0 设置为1,忽略损耗的
MariaDB [(none)]> SHOW GLOBAL VARIABLES LIKE '%slave%';
+------------------------------------+------------+
| Variable_name | Value |
+------------------------------------+------------+
| init_slave | |
| log_slave_updates | OFF |
| rpl_semi_sync_master_wait_no_slave | ON |
| slave_compressed_protocol | OFF |
| slave_exec_mode | STRICT |
| slave_load_tmpdir | /tmp |
| slave_max_allowed_packet | 1073741824 |
| slave_net_timeout | 3600 |
| slave_skip_errors | OFF |
| slave_sql_verify_checksum | ON |
| slave_transaction_retries | 10 |
| slave_type_conversions | |
| sql_slave_skip_counter | 0 |
+------------------------------------+------------+
13 rows in set (0.00 sec)

MariaDB [(none)]>

从服务器是否落后与主服务器:
MariaDB [(none)]> show slave status\G

Seconds_Behind_Master: NULL NULL则线程未启动
Seconds_Behind_Master: 0 0则没有延迟

这个数值如果只是在波动,而不是在变大,则问题不大,如果一旦数值变大,则手动介入

安装包:percona-toolkit-2.2.4-1.noarch.rpm
pt-summary 查看系统性能

[root@mysql-slave local]# pt-summary 
# Percona Toolkit System Summary Report ######################
        Date | 2016-02-15 05:50:26 UTC (local TZ: PST -0800)
    Hostname | mysql-slave
      Uptime | 10 days, 22:53,  2 users,  load average: 0.00, 0.00, 0.00
      System | VMware, Inc.; VMware Virtual Platform; vNone (Other)
 Service Tag | VMware-56 4d 08 c9 78 a4 5b 25-a5 cb 55 d1 96 68 3c f5
    Platform | Linux
     Release | CentOS release 6.6 (Final)
      Kernel | 2.6.32-573.3.1.el6.x86_64
Architecture | CPU = 64-bit, OS = 64-bit
   Threading | NPTL 2.12
    Compiler | GNU CC version 4.4.7 20120313 (Red Hat 4.4.7-16).
     SELinux | Permissive
 Virtualized | VMWare
# Processor ##################################################
  Processors | physical = 1, cores = 1, virtual = 1, hyperthreading = no
      Speeds | 1x3092.889
      Models | 1xIntel(R) Core(TM) i5-4440 CPU @ 3.10GHz
      Caches | 1x6144 KB
# Memory #####################################################
       Total | 981.2M
        Free | 260.3M
        Used | physical = 720.9M, swap allocated = 1.9G, swap used = 0.0, virtual = 720.9M
     Buffers | 154.9M
      Caches | 284.2M
       Dirty | 364 kB
     UsedRSS | 205.0M
  Swappiness | 60
 DirtyPolicy | 20, 10
 DirtyStatus | 0, 0
  Locator   Size     Speed             Form Factor   Type          Type Detail
  ========= ======== ================= ============= ============= ===========
  RAM slot #0 1024 MB  Unknown           DIMM          DRAM          EDO     
  RAM slot #10 {EMPTY}  Unknown           DIMM          DRAM          Unknown 
  RAM slot #11 {EMPTY}  Unknown           DIMM          DRAM          Unknown 
  RAM slot #9 {EMPTY}  Unknown           DIMM          DRAM          Unknown 
# Mounted Filesystems ########################################
  Filesystem  Size Used Type  Opts                                          Mountpoint
  /dev/sda1   283M  23% ext4  rw                                            /boot
  /dev/sda2    18G  36% ext4  rw                                            /
  tmpfs       491M   0% tmpfs rw,rootcontext="system_u:object_r:tmpfs_t:s0" /dev/shm
# Disk Schedulers And Queue Size #############################
         sda | [cfq] 128
         sr0 | [cfq] 128
# Disk Partioning ############################################
Device       Type      Start        End               Size
============ ==== ========== ========== ==================
/dev/sda     Disk                              21474836480
/dev/sda1    Part          1         39          312560640
/dev/sda2    Part         39       2358        19074424320
/dev/sda3    Part       2358       2611         2080995840
# Kernel Inode State #########################################
dentry-state | 46604    38113   45  0   0   0
     file-nr | 960  0   96182
    inode-nr | 40658    93
# LVM Volumes ################################################
Unable to collect information
# LVM Volume Groups ##########################################
Unable to collect information
# RAID Controller ############################################
  Controller | No RAID controller detected
# Network Config #############################################
  Controller | Intel Corporation 82545EM Gigabit Ethernet Controller (Copper) (rev 01)
 FIN Timeout | 60
  Port Range | 61000
# Interface Statistics #######################################
  interface  rx_bytes rx_packets  rx_errors   tx_bytes tx_packets  tx_errors
  ========= ========= ========== ========== ========== ========== ==========
  lo             6000         80          0       6000         80          0
  eth2       30000000     400000          0    4000000      60000          0
# Network Devices ############################################
  Device    Speed     Duplex
  ========= ========= =========
  eth2       1000Mb/s   Full      
# Network Connections ########################################
  Connections from remote IP addresses
    192.168.0.3         2
  Connections to local IP addresses
    192.168.0.100       2
  Connections to top 10 local ports
    22                  2
  States of connections
    ESTABLISHED         2
    LISTEN             10
# Top Processes ##############################################
   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
     1 root      20   0 19356 1540 1228 S  0.0  0.2   0:01.43 init
     2 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kthreadd
     3 root      RT   0     0    0    0 S  0.0  0.0   0:00.00 migration/0
     4 root      20   0     0    0    0 S  0.0  0.0   0:04.03 ksoftirqd/0
     5 root      RT   0     0    0    0 S  0.0  0.0   0:00.00 stopper/0
     6 root      RT   0     0    0    0 S  0.0  0.0   0:01.84 watchdog/0
     7 root      20   0     0    0    0 S  0.0  0.0  14:22.34 events/0
     8 root      20   0     0    0    0 S  0.0  0.0   0:00.00 events/0
     9 root      20   0     0    0    0 S  0.0  0.0   0:00.00 events_long/0
# Notable Processes ##########################################
  PID    OOM    COMMAND
 1710    -17    sshd
# Simplified and fuzzy rounded vmstat (wait please) ##########
  procs  ---swap-- -----io---- ---system---- --------cpu--------
   r  b    si   so    bi    bo     ir     cs  us  sy  il  wa  st
   1  0     0    0     0     3     25     10   0   0 100   0   0
   0  0     0    0     0     0    400    800  11  20  69   0   0
   0  0     0    0     0     0     60     70   0   1  99   0   0
   0  0     0    0     0     0     25     60   0   0 100   0   0
   0  0     0    0     0     0     30     60   0   1  99   0   0
# The End ####################################################
[root@mysql-slave local]# 

第三方复制解决方案: Tungsten,Galera

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日期: 2016-02-15分类: Mariadb

标签: mariadb

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