grafana 4 升级到 grafana 5错误处理

遇到2个错误：

1. UNIQUE KEY 问题

INFO[07-16|15:34:36] Executing migration logger=migrator id="Remove unique index org_id_slug"
EROR[07-16|15:34:36] Executing migration failed logger=migrator id="Remove unique index org_id_slug" error="Error 1091: Can't DROP 'UQE_dashboard_org_id_slug'; check that column/key exists"
EROR[07-16|15:34:36] Exec failed logger=migrator error="Error 1091: Can't DROP 'UQE_dashboard_org_id_slug'; check that column/key exists" sql="DROP INDEX `UQE_dashboard_org_id_slug` ON `dashboard`"
EROR[07-16|15:34:36] Server shutdown logger=server reason="Service init failed: Migration failed err: Error 1091: Can't DROP 'UQE_dashboard_org_id_slug'; check that column/key exists"

故障原因，原数据库中的`dashboard`表没有“UQE_dashboard_org_id_slug”这个UNIQUE KEY ，所以在删除的时候失败了。

2. Convert existing annotations from seconds to milliseconds问题

INFO[07-16|17:13:41] Executing migration                      logger=migrator id="Convert existing annotations from seconds to milliseconds"
EROR[07-16|17:13:41] Executing migration failed               logger=migrator id="Convert existing annotations from seconds to milliseconds" error="Error 1264: Out of range value for column 'epoch' at row 1"
EROR[07-16|17:13:41] Exec failed                              logger=migrator error="Error 1264: Out of range value for column 'epoch' at row 1" sql="UPDATE annotation SET epoch = (epoch*1000) where epoch < 9999999999"
EROR[07-16|17:13:41] Server shutdown                          logger=server reason="Service init failed: Migration failed err: Error 1264: Out of range value for column 'epoch' at row 1"

故障原因，原表annotation的字段epoch类型是int，但是新版grafana中，需要将该字段的秒转换为毫秒，长度不够用了，执行转换的sql语句执行失败。

解决方案：

1，导出当前grafana使用的数据库内容：

mysqldump -uroot -hlocalhost -p grafana > grafana.sql

2, 编辑导出的sql文件，将int(11)替换为bigint(20)

vi grafana.sql

:%s/int(11)/int(20)/g

3，找到`dashboard`表的创建语句，添加UNIQUE KEY `UQE_dashboard_org_id_slug`，例如：

DROP TABLE IF EXISTS `dashboard`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `dashboard` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `version` bigint(20) NOT NULL,
  `slug` varchar(189) COLLATE utf8mb4_unicode_ci NOT NULL,
  `title` varchar(255) COLLATE utf8mb4_unicode_ci NOT NULL,
  `data` mediumtext COLLATE utf8mb4_unicode_ci NOT NULL,
  `org_id` bigint(20) NOT NULL,
  `created` datetime NOT NULL,
  `updated` datetime NOT NULL,
  `updated_by` bigint(20) DEFAULT NULL,
  `created_by` bigint(20) DEFAULT NULL,
  `gnet_id` bigint(20) DEFAULT NULL,
  `plugin_id` varchar(189) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `UQE_dashboard_org_id_slug` (`org_id`,`slug`),
  KEY `IDX_dashboard_org_id` (`org_id`),
  KEY `IDX_dashboard_gnet_id` (`gnet_id`)
) ENGINE=InnoDB AUTO_INCREMENT=187 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

4，创建新的数据库，然后导入刚刚编辑的sql文件。

create database grafana5  DEFAULT CHARACTER SET utf8 COLLATE utf8_bin;
use grafana5
source  ./grafana.sql;

5, 为grafana账号添加新数据库授权，然后修改新版本配置文件，使用刚创建的数据库。

然后再重新启动grafana5，启动后会自动进行旧数据转换，转换完毕访问grafana的页面，你会发现旧版所有内容都已经可以在新版上访问啦。