metrcs中大于255长度的tags无法写入mysql数据库 about owl HOT 1 CLOSED

1，将metric表中 tags字段改为 text
2，将索引 改为tags（255）
改后的表为：
CREATE TABLE metric (
id int(10) unsigned NOT NULL AUTO_INCREMENT,
host_id char(32) COLLATE utf8_unicode_ci NOT NULL,
metric varchar(255) COLLATE utf8_unicode_ci NOT NULL COMMENT 'cpu.idle/cpu=all',
tags text COLLATE utf8_unicode_ci NOT NULL,
dt enum('GAUGE','DERIVE','COUNTER') COLLATE utf8_unicode_ci NOT NULL,
cycle int(10) NOT NULL,
create_at datetime NOT NULL,
update_at datetime NOT NULL,
PRIMARY KEY (id),
UNIQUE KEY idx_name (metric,host_id,tags(255)) USING BTREE,
KEY fk_metric_host (host_id),
CONSTRAINT fk_metric_host FOREIGN KEY (host_id) REFERENCES host (id) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=4989794 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

from owl.