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kingshard SQL黑名单功能介绍

1. 应用场景介绍

在kingshard开源之后，有用户多次提到能不能在kingshard中加入SQL黑名单机制，让kingshard能够根据特定的规则来拦截在黑名单中的SQL。有几个比较典型的应用场景：

delete from mytable select count(*) from mytable where xxxx

2. 功能介绍

在kingshard如果想使用SQL黑名单功能，只需要在配置中添加：

blacklist_sql_file: /Users/flike/blacklist

然后我们在blacklist定义SQL黑名单，这样kingshard在转发的时候，就会阻止黑名单中SQL的转发。

黑名单SQL以正则表达式的形式定义。对于SQL中的值用 ? 或 ?+ 代替。为保证黑名单有效，最好手动验证一下，kingshard是否正确拦截了黑名单中的SQL。定义规则（上一条是原SQL，对应的下一条是黑名单形式的SQL）可以参考下列例子：

SELECT c FROM t WHERE id=1 select c from t where id=?  SELECT * FROM prices.rt_5min where id=1 select * from prices.rt_5min where id=?  select null, 5.001, 5001. from foo select ?, ?, ? from foo  select 'hello', '/nhello/n', /"hello/", '//'' from foo select ?, ?, ?, ? from foo  select 'hello'/n select ?  select * from t where (base.nid IN  ('1412', '1410', '1411')) select * from t where (base.nid in(?+))  select * from foo where a in (5) and b in (5, 8,9 ,9 , 10) select * from foo where a in(?+) and b in(?+)  select * from foo limit 5 select * from foo limit ?  select * from foo limit 5, 10 select * from foo limit ?, ?  select * from foo limit 5 offset 10 select * from foo limit ? offset ?  INSERT INTO t (ts) VALUES (NOW()) insert into t (ts) values(?+)  insert into foo(a, b, c) values(2, 4, 5) insert into foo(a, b, c) values(?+)  CALL foo(1, 2, 3) call foo  LOAD DATA INFILE '/tmp/foo.txt' INTO db.tbl load data infile ? into db.tbl  administrator command: Init DB administrator command: Init DB  use `foo` use ?

3.功能演示

在blacklist加入如下SQL:

select count(*) from test_shard_hash where id > ? select count(*) from test_shard_range SELECT * FROM WORLD DELETE FROM WORLD

连接kingshard，执行SQL显示如下：

mysql> select * from world; ERROR 1105 (HY000): sql in blacklist. mysql> select * from world where a > 0; +------+------+ | a    | b    | +------+------+ |   10 |   23 | |   45 |  565 | +------+------+ 2 rows in set (0.00 sec)  mysql> delete from world; ERROR 1105 (HY000): sql in blacklist. mysql> delete from world where a =10; Query OK, 1 row affected (0.00 sec) #注意在SQL黑名单中该SQL是大于后面有个空格，必须要严格匹配，否则#kingshard不会认为是黑名单SQL mysql> select count(*) from test_shard_hash where id >1; +----------+ | count(*) | +----------+ |       24 | +----------+ 1 row in set (0.02 sec)  mysql> select count(*) from test_shard_hash where id > 1; ERROR 1105 (HY000): sql in blacklist.

用sysbench测试了一下存在blacklist时kingshad的性能，发现性能并没有明显下降，所以可以放心使用该功能。

原文 http://segmentfault.com/a/1190000004359414

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