Mysql 5.7 Innodb随机删除查询非常慢

Question

I have table with 5 simple fields. Total rows in table is cca 250.

When I use PHPmyAdmin with one DELETE query it is processed in 0.05 sec. (always).

Problem is that my PHP application (PDO connection) processing same query between other queries and this query is extremely slow (cca 10 sec.). And another SELECT query on table with 5 rows too (cca 1 sec.). It happened only sometimes! Other queries (cca 100) are always OK with normal time response.

What problem should be or how to find what is the problem?

Table:

CREATE TABLE `list_ip` (
`id` INT(11) NOT NULL AUTO_INCREMENT,
`type` CHAR(20) NOT NULL DEFAULT '',
`address` CHAR(50) NOT NULL DEFAULT '',
`description` VARCHAR(50) NOT NULL DEFAULT '',
`datetime` DATETIME NOT NULL DEFAULT '1000-01-01 00:00:00',
PRIMARY KEY (`id`),
INDEX `address` (`address`),
INDEX `type` (`type`),
INDEX `datetime` (`datetime`) ) COLLATE='utf8_general_ci' ENGINE=InnoDB;

Query:

DELETE FROM list_ip WHERE address='1.2.3.4' AND type='INT' AND datetime<='2017-12-06 08:04:30';

As I said before table has only 250 rows. Size of table is 96Kib. I tested also with empty table and its slow too.

Answer 1

Wrap your query in EXPLAIN and see if it's running a sequential select, not using indexes. EXPLAIN would be my first stop in determining if I have a data model problem (bad / missing indexes would be one model issue).

About EXPLAIN: https://dev.mysql.com/doc/refman/5.7/en/explain.html

Another tool I'd recommend is running 'mytop' and looking at the server activity/load during those times when it's bogging down. http://jeremy.zawodny.com/mysql/mytop/

Answer 2

There was some network problem. I uninstalled docker app with some network peripherals and looks much beter.