一、MySQL Fabric高可用集群中一台数据库崩溃了,不影响数据的完整性 1.测试前准备 a) 查看group_id-1集群组的服务器状态 mysqlfabric group lookup_servers group_id-1 |
返回结果: Command :
{ success = True
return = [{'status': 'PRIMARY', 'server_uuid': '7a45f71d-7934-11e4-9e8c-782bcb74823a', 'mode': 'READ_WRITE', 'weight': 1.0, 'address': '192.168.1.71:3306'}, {'status': 'SECONDARY', 'server_uuid': '9cf162ca-7934-11e4-9e8d-782bcb1b6b98','mode': 'READ_ONLY', 'weight': 1.0, 'address': '192.168.1.76:3306'}, {'status': 'SECONDARY', 'server_uuid': 'ae94200b-7932-11e4-9e81-a4badb30e16b', 'mode': 'READ_ONLY', 'weight': 1.0, 'address': '192.168.1.70:3306'}]
activities =} |
此时primary机为机器:192.168.1.71:3306,group_id-1集群组正常 b) 查看group_id-1集群组中的数据 mysql -P 3306 -h 192.168.1.76 -u root -e "select * from test.subscribers"
mysql -P 3306 -h 192.168.1.71 -u root -e "select * from test.subscribers"
mysql -P 3306 -h 192.168.1.70 -u root -e "select * from test.subscribers"
返回结果如下:
+--------+------------+-----------+
| sub_no | first_name | last_name |
+--------+------------+-----------+
| 500 | Billy | Joel |
| 1500 | Arthur | Askey |
| 5000 | Billy | Fish |
| 17542 | Bobby | Ball |
| 22 | Billy | Bob |
| 8372 | Banana | Man |
| 93846 | Bill | Ben |
| 15050 | John | Smith |
+--------+------------+-----------+ |
c) 利用python接口查看数据库test的数据表subscribers分片后的全部数据 返回结果如下: (u'Billy', u'Bob')
(u'Billy', u'Fish')
(u'Billy', u'Joel')
(u'Arthur', u'Askey')
(u'Banana', u'Man')
(u'Billy', u'Fish')
(u'Bill', u'Ben')
(u'Jimmy', u'White')
(u'John', u'Smith')
(u'Bobby', u'Ball') |
2.开始测试 a) 激活故障自动切换 即使Fabric选出了master角色,但当这个master角色宕机时,fanric不会自动将secondary角色切换为master角色,所以需要将HA集群组的配置改为自动切换角色 mysqlfabric group activate group_id-1 |
b) 停止group_id-1组中的master角色,即数据库实例192.168.1.71:3306,再查看fabric的状态 mysqlfabric group lookup_servers group_id-1 |
返回结果: Command :
{ success = True
return = [{'status': 'FAULTY', 'server_uuid': '7a45f71d-7934-11e4-9e8c-782bcb74823a', 'mode': 'READ_WRITE', 'weight': 1.0, 'address': '192.168.1.71:3306'}, {'status': 'SECONDARY', 'server_uuid': '9cf162ca-7934-11e4-9e8d-782bcb1b6b98', 'mode': 'READ_ONLY', 'weight': 1.0, 'address': '192.168.1.76:3306'}, {'status': 'PRIMARY', 'server_uuid': 'ae94200b-7932-11e4-9e81-a4badb30e16b', 'mode': 'READ_WRITE', 'weight': 1.0, 'address': '192.168.1.70:3306'}]
activities =} |
其中,数据库实例192.168.1.71:3306的状态为FAULTY,mysql fabric自动检测到了HA组的故障,并自动选举了slave角色为primary角色 c) 查看group_id-1集群组中的数据 mysql -P 3306 -h 192.168.1.76 -u root -e "select * from test.subscribers"
mysql -P 3306 -h 192.168.1.70 -u root -e "select * from test.subscribers" |
返回结果: +--------+------------+-----------+
| sub_no | first_name | last_name |
+--------+------------+-----------+
| 500 | Billy | Joel |
| 1500 | Arthur | Askey |
| 5000 | Billy | Fish |
| 17542 | Bobby | Ball |
| 22 | Billy | Bob |
| 8372 | Banana | Man |
| 93846 | Bill | Ben |
| 15050 | John | Smith |
+--------+------------+-----------+ |
d) 利用python接口查看数据库test的数据表subscribers分片后的全部数据 返回结果: (u'Billy', u'Bob')
(u'Billy', u'Fish')
(u'Billy', u'Joel')
(u'Arthur', u'Askey')
(u'Banana', u'Man')
(u'Billy', u'Fish')
(u'Bill', u'Ben')
(u'Jimmy', u'White')
(u'John', u'Smith')
(u'Bobby', u'Ball') |
结论:由以上测试返回数据表明,当HA组(group_id-1)中的master角色崩溃,mysql fabric会自动选举一个slave角色为master,并可正常查询原来的数据,因此当mysql fabric高可用集群中某一台数据库崩溃掉,并不影响数据的完整性 PS:手工恢复FAULT状态的数据库实例 mysql fabric高可用集群中的服务器状态有四种:primary、secondary、faulty、spare 关闭primary,primary不能从组中移除,需要使用mysqlfabric group demote group_id-1来关闭组中的primary,不会重新选举一个新的master,同时也不会关闭故障检测 a) 当其中的一个数据库实例崩溃,可以将这个数据库实例从组中删除,启动这个数据库实例后再重新添加,例如: mysqlfabric group remove group_id-1 7a45f71d-7934-11e4-9e8c-782bcb74823a
mysqlfabric group add group_id-1 192.168.1.71:3306
mysqlfabric group lookup_servers group_id-1 |
返回结果: Command :
{ success = Truereturn = [{'status': 'SECONDARY', 'server_uuid': '7a45f71d-7934-11e4-9e8c-782bcb74823a', 'mode': 'READ_ONLY','weight': 1.0, 'address': '192.168.1.71:3306'}, {'status': 'SECONDARY', 'server_uuid': '9cf162ca-7934-11e4-9e8d-782bcb1b6b98', 'mode': 'READ_ONLY', 'weight': 1.0, 'address': '192.168.1.76:3306'}, {'status': 'PRIMARY', 'server_uuid': 'ae94200b-7932-11e4-9e81-a4badb30e16b','mode': 'READ_WRITE', 'weight': 1.0, 'address': '192.168.1.70:3306'}] activities =} |
b) 当HA组中全部的服务器宕机,实例重启后,fabric的状态不会自动恢复,需要先执行命令:mysqlfabric group demote group_id-1,因为不能直接修改server的状态由faulty为secondary,需要将状态修改为spare,在改为secondary,如下: mysqlfabric group demote group_id-1
mysqlfabric group deactivate group_id-1
mysqlfabric server set_status 7a45f71d-7934-11e4-9e8c-782bcb74823a spare
mysqlfabric server set_status 7a45f71d-7934-11e4-9e8c-782bcb74823a secondary |
###当所有的数据库实例都为secondary状态时,可选举master角色,命令如下: mysqlfabric group promote group_id-1 |
二、MySQL Fabric高可用集群存储均衡 1.测试前准备 a) 测试脚本 cat test_add_subs_shards.py
import mysql.connector
from mysql.connector import fabric
import math
def add_subscriber(conn, sub_no, first_name, last_name):
conn.set_property(tables=["test.subscribers"], key=sub_no, \
mode=fabric.MODE_READWRITE)
cur = conn.cursor()
cur.execute(
"INSERT INTO subscribers VALUES (%s, %s, %s)",
(sub_no, first_name, last_name)
)
conn = mysql.connector.connect(
fabric={"host" : "localhost", "port" : 32274, "username": "admin", \
"password" : "admin"},
user="root", database="test", password="",
autocommit=True
)
conn.set_property(tables=["test.subscribers"], scope=fabric.SCOPE_LOCAL)
for num in range(10):
add_subscriber(conn, "%s" % num, "k%s" % num, "kw%s" % num) |
2.开始hash分片测试 a)插入10条记录,当group_id-1组的三台服务器正常,group_id-2组只有一台服务器正常运作时, group_id-1组的数据如下: b) 测试插入1万条记录,group_id-1组和group_id-2组都有三台服务器正常运作 分片后,group_id-1组插入的数据行数如下: mysql -P 3306 -h 192.168.1.70 -u root -e "select count(*) from test.subscribers" |
返回结果: +----------+
| count(*) |
+----------+
| 7138 |
+----------+ |
分片后,group_id-2组插入的数据行数如下: mysql -P 3309 -h 192.168.1.76 -u root -e "select count(*) from test.subscribers" |
返回结果: +----------+
| count(*) |
+----------+
| 2903 |
+----------+ |
c) 测试插入10万条记录,group_id-1组和group_id-2组都有三台服务器正常运作 分片后,group_id-1组插入的数据行数如下: mysql -P 3306 -h 192.168.1.70 -u root -e "select count(*) from test.subscribers" |
返回结果: +----------+
| count(*) |
+----------+
| 78719 |
+----------+
mysql -P 3309 -h 192.168.1.76 -u root -e "select count(*) from test.subscribers" |
返回结果: +----------+
| count(*) |
+----------+
| 31321 |
+----------+ |
d) 测试插入100万条记录,group_id-1组和group_id-2组都有三台服务器正常运作 分片后,group_id-1组插入的数据行数如下: mysql -P 3306 -h 192.168.1.70 -u root -e "select count(*) from test.subscribers" |
返回结果: +----------+
| count(*) |
+----------+
| 794287 |
+----------+ |
分片后,group_id-2组插入的数据行数如下: mysql -P 3309 -h 192.168.1.76 -u root -e "select count(*) from test.subscribers" |
返回结果: +----------+
| count(*) |
+----------+
| 315752 |
+----------+ |
添加一个新HA组(group_id-3),对HA组(group_id-1)进行分片,操作如下: a) 在机器:192.168.1.71 192.168.1.76 192.168.1.230上各起一个数据库实例,添加为组group_id-3 mysqlfabric group add group_id-3 192.168.1.71:3313
mysqlfabric group add group_id-3 192.168.1.76:3315
mysqlfabric group add group_id-3 192.168.1.230:3317 |
选举primary角色 mysqlfabric group promote group_id-3 |
b) 重置HA组group_id-3所有的数据库实例 mysql -P 3313 -h 192.168.1.71 -u root -e "reset master"
mysql -P 3315 -h 192.168.1.76 -u root -e "reset master"
mysql -P 3317 -h 192.168.1.230 -u root -e "reset master" |
c) 查看HA组(group_id-1)的shard_id值,在储存机查看fabric数据库 mysql -h 127.0.0.1 -P3306 -u root -e 'select * from fabric.shards' |
返回结果: +----------+------------+---------+
| shard_id | group_id | state |
+----------+------------+---------+
| 4 | group_id-1 | ENABLED |
| 5 | group_id-2 | ENABLED |
+----------+------------+---------+ |
d) 对HA组(group_id-1)进行分片分离,将 mysqlfabric sharding split_shard 4 group_id-3 |
ps:如果这里执行分片不成功,错误如下: Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'could not find next log; the first event '' at 4, the last event read from './binlog.000003' at 621, the last byte read from './binlog.000003' at 621.' |
解决方法: 将master角色的数据dump出来,如下: mysqldump -h 192.168.1.76 -u root -P3315 --all-databases --flush-privileges --single-transaction --flush-logs --triggers --routines --events --hex-blob >/data/database/full_backup_master.sql |
停掉slave机 mysql -P 3317 -h 192.168.1.230 -u root -e "stop slave"
mysql -P 3317 -h 192.168.1.230 -u root -e "reset master"
mysql -P 3317 -h 192.168.1.230 -u root </data/full_backup_master.sql
mysql -P 3317 -h 192.168.1.230 -u root -e "start slave" |
再次执行分片,会报以下错误: Procedure :
{ uuid = 4da230c2-31c3-4242-bd88-ccafd51bfac1,
finished = True,
success = False,
return = BackupError: ('Error while restoring the backup using the mysql client\n, %s', "ERROR 1840 (HY000) at line 24 in file: 'MySQL_192.168.1.76_3306.sql': @@GLOBAL.GTID_PURGED can only be set when @@GLOBAL.GTID_EXECUTED is empty.\n"),
activities =} |
解决方法: 在HA组(group_id-3)的全部数据库实例上执行“reset master”,再分片即可 e) 现在HA组有group_id-1、group_id-2、group_id-3,尝试插入100条记录 group_id-1的插入的数据行数有: mysql -P 3306 -h 192.168.1.70 -u root -e "select count(*) from test.subscribers where sub_no between 20000 and 20100" |
返回结果: +----------+
| count(*) |
+----------+
| 70 |
+----------+ |
group_id-2、group_id-3的插入的数据行数有: mysql -P 3309 -h 192.168.1.76 -u root -e "select count(*) from test.subscribers where sub_no between 20000 and 20100"
mysql -P 3313 -h 192.168.1.230 -u root -e "select count(*)from test.subscribers where sub_no between 20000 and 20100" |
返回结果: +----------+
| count(*) |
+----------+
| 30 |
+----------+ |
用select语句可知,HA组group_id-2、group_id-3插入的数据是一样的 3.hash分片测试结论 在插入1万条记录时,HA组(group_id-1)插入了7138条记录,HA组(group_id-2)插入了2903条记录 在插入10万条记录时,HA组(group_id-1)插入了78719条记录,HA组(group_id-2)插入了31321条记录 在插入100万条记录时,HA组(group_id-1)插入了794287条记录,HA组(group_id-2)插入了315752条记录 因此,对mysql fabric高集群进行hash分片后,分片比例为7:3,负载并不是十分均衡
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