Elasticsearch(ES)可用于全文检索、日志分析、指标分析、APM等众多场景,而且搭建部署容易,后期弹性扩容、故障处理简单。ES在一定程度上实现了一套系统支持多个场景的希望,大幅度降低使用多套专用系统的运维成本(当然ES不是万能的,不能满足事务等场景)。正是因为其通用性和易用性,ES自2010年发布首个版本以来得到爆发式的发展,广泛应用于各类互联网公司的不同业务场景,在数据库的专业排名中(DB Engines)上升至第8位。
对于很多用户,想要将Mysql中的数据导入到ES中,而又找不到一种较好的方法,笔者这里给出一种简单快捷的方式,轻松将Mysql中的数据同步到ES。
go-mysql-elasticsearch是一款开源的高性能的Mysql数据同步ES的工具,其由go语言开发,编译及使用非常简单。go-mysql-elasticsearch的原理很简单,首先使用mysqldump获取当前MySQL的数据,然后在通过此时binlog的name和position获取增量数据,再根据binlog构建restful api写入数据到ES中。下面笔者将会给出详细的使用步骤。
既然读者有Mysql导入ES的需求,那Mysql的安装就不用多说了。这里笔者为了整个流程的完整性,就从样例数据的灌入开始,笔者用go写了一个小工具,生成一些样例数据并灌入到Mysql中,表结构如下:
mysql> desc test_table;
+-----------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------+-------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| timestamp | bigint(20) | YES | | NULL | |
| cpu_usage | float | YES | | NULL | |
| host_ip | varchar(20) | YES | | NULL | |
| region | varchar(20) | YES | | NULL | |
+-----------+-------------+------+-----+---------+----------------+
以上创建了一个名为test_table的表,然后向该表灌入2000条样例数据,部分数据如下所示:
mysql> select * from test_table;
+------+------------+-----------+-------------+-----------+
| id | timestamp | cpu_usage | host_ip | region |
+------+------------+-----------+-------------+-----------+
| 1 | 1527676339 | 0.23 | 192.168.1.1 | beijing |
| 2 | 1527676399 | 0.78 | 192.168.1.2 | shanghai |
| 3 | 1527676459 | 0.2 | 192.168.1.3 | guangzhou |
| 4 | 1527676519 | 0.47 | 192.168.1.4 | shanghai |
| 5 | 1527676579 | 0.13 | 192.168.1.5 | beijing |
| 6 | 1527676639 | 0.15 | 192.168.1.1 | beijing |
| 7 | 1527676699 | 0.07 | 192.168.1.2 | shanghai |
| 8 | 1527676759 | 0.17 | 192.168.1.3 | guangzhou |
| 9 | 1527676819 | 0.94 | 192.168.1.4 | shanghai |
| 10 | 1527676879 | 0.06 | 192.168.1.5 | beijing |
至此,Mysql端的样例数据准备完毕。
由于go-mysql-elasticsearch是用go语言开发,因此首先安装go,官方要求的版本是1.6以上,go的安装非常简单,参考官方文档,下载:https://golang.org/dl/, 安装:https://golang.org/doc/install#install, 然后开始安装 go-mysql-elasticsearch,整个步骤如下:
$ go get github.com/siddontang/go-mysql-elasticsearch
$ cd $GOPATH/src/github.com/siddontang/go-mysql-elasticsearch
$ make
工具安装好后,需要进行一些合理地配置我们才能愉快地使用,下面笔者将会给出一个配置范例,并给予相应地注释说明:
# 注意:go-mysql-elasticsearch的默认配置文件在go-mysql-elasticsearch/etc/river.toml # MySQL address, user and password # user must have replication privilege in MySQL. my_addr = "127.0.0.1:3306" my_user = "root" my_pass = "123456" my_charset = "utf8" # Set true when elasticsearch use https #es_https = false # ES 地址 es_addr = "9.6.174.42:13982" # 如果使用的是带权限的ES,需要设置用户名和密码 #es_user = "root" #es_pass = "changeme" # Path to store data, like master.info, if not set or empty, # we must use this to support breakpoint resume syncing. # TODO: support other storage, like etcd. data_dir = "./var" # 存储的是binlog的名字及位置 # Inner Http status address stat_addr = "127.0.0.1:12800" # pseudo server id like a slave server_id = 1001 # mysql or mariadb flavor = "mysql" # mysqldump execution path # if not set or empty, ignore mysqldump. mysqldump = "mysqldump" # minimal items to be inserted in one bulk bulk_size = 512 # force flush the pending requests if we don't have enough items >= bulk_size flush_bulk_time = "200ms" # Ignore table without primary key skip_no_pk_table = true # 这里需要注意,go-mysql-elasticsearch会 # MySQL data source [[source]] schema = "mysql_es" # Only below tables will be synced into ES. # "t_[0-9]{4}" is a wildcard table format, you can use it if you have many sub tables, like table_0000 - table_1023 # I don't think it is necessary to sync all tables in a database. tables = ["test_table*"] [[rule]] schema = "mysql_es" # Mysql数据库名 table = "test_table" # Mysql表名 index = "test_index" # ES中index名 type = "doc" # 文档类型
以上配置,为笔者测试所使用的配置,如果用户有更高级的需求可以参考官方文档,合理进行配置。配置ok后,我们来运行go-mysql-elasticsearch,如下所示:
$ ./bin/go-mysql-elasticsearch -config=./etc/river.toml 2018/05/31 21:43:44 INFO create BinlogSyncer with config {1001 mysql 127.0.0.1 3306 root utf8 false false <nil> false false 0 0s 0s 0} 2018/05/31 21:43:44 INFO run status http server 127.0.0.1:12800 2018/05/31 21:43:44 INFO skip dump, use last binlog replication pos (mysql-bin.000002, 194296) or GTID %!s(<nil>) 2018/05/31 21:43:44 INFO begin to sync binlog from position (mysql-bin.000002, 194296) 2018/05/31 21:43:44 INFO register slave for master server 127.0.0.1:3306 2018/05/31 21:43:44 INFO start sync binlog at binlog file (mysql-bin.000002, 194296) 2018/05/31 21:43:44 INFO rotate to (mysql-bin.000002, 194296) 2018/05/31 21:43:44 INFO rotate binlog to (mysql-bin.000002, 194296) 2018/05/31 21:43:44 INFO save position (mysql-bin.000002, 194296)
这里需要 注意 ,由于go-mysql-elasticsearch需要利用binlog,而且binlog一定要变成row-based format格式,同时需要用到canal组件来同步数据(canal模拟mysql slave的交互协议,伪装自己为mysql slave,向mysql master发送dump协议),因此在Mysql必须配置如下参数:
# 以下参数需要配置,否则必踩坑
log_bin=mysql-bin
binlog_format = ROW
server-id=1
现在,我们来看看ES中是否成功导入了Mysql中的数据:
#命令: GET test_index/_search?size=1000 { "sort": [ { "timestamp": { "order": "desc" } } ], "docvalue_fields": ["timestamp", "host_ip", "region", "cpu_usage"] } #结果: { "took": 8, "timed_out": false, "_shards": { "total": 3, "successful": 3, "skipped": 0, "failed": 0 }, "hits": { "total": 2000, "max_score": null, "hits": [ { "_index": "test_index", "_type": "doc", "_id": "2000", "_score": null, "fields": { "host_ip": [ "192.168.1.5" ], "region": [ "beijing" ], "cpu_usage": [ 0.05000000074505806 ], "timestamp": [ 1527807286000 ] }, "sort": [ 1527807286000 ] }, ...... }
从total可以看出,2000条数据完全导入,至此,Mysql数据导入成功。
对于一些项目如果使用了分表机制,我们可以用通配符来匹配,这里假设我们需要同步test_table和test_table1两个表到Elasticsearch的同一个index下,只需将上述中的rule配置改为:
[[rule]]
schema = "mysql_es" # Mysql数据库名
table = "test_table*" # Mysql表名,这里的table必须在source下的tables里
index = "test_index" # Elasticsearch中index名
type = "doc" # 文档类型
为了验证配置是否生效,笔者在mysql中另外建了一张表test_table1,并插入三条测试数据:
mysql> select * from test_table1;
+------+------------+-----------+-------------+-----------+
| id | timestamp | cpu_usage | host_ip | region |
+------+------------+-----------+-------------+-----------+
| 3333 | 1528960639 | 0.55 | 192.168.1.2 | chongqing |
| 4444 | 1528960649 | 0.56 | 192.168.1.3 | chengdu |
| 5555 | 1528960649 | 0.58 | 192.168.1.6 | shenzhen |
+------+------------+-----------+-------------+-----------+
然后清空go-mysql-elasticsearch下的var目录,重启程序,再看看ES中同步的数据:
"hits": { "total": 2003, "max_score": null, "hits": [ { "_index": "test_index", "_type": "doc", "_id": "5555", "_score": null, "fields": { "host_ip": [ "192.168.1.6" ], "region": [ "shenzhen" ], "cpu_usage": [ 0.5799999833106995 ], "timestamp": [ 1528960649000 ] }, "sort": [ 1528960649000 ] }, { "_index": "test_index", "_type": "doc", "_id": "4444", "_score": null, "fields": { "host_ip": [ "192.168.1.3" ], "region": [ "chengdu" ], "cpu_usage": [ 0.5600000023841858 ], "timestamp": [ 1528960649000 ] }, "sort": [ 1528960649000 ] }, ... ...
从上述结果可以看出,ES中有2003条数据,至此,test_table、test_table1中的数据都成功同步到ES。
可以看到,使用 go-mysql-elasticsearch,我们仅需要在配置文件里面写规则,就能非常方便的将数据从 MySQL 同步给 ES。上面仅仅举了一些简单的例子,如果有更多的需求可以参考 go-mysql-elasticsearch的官方文档。
除了本文所介绍的工具外,这里再推荐两种工具,一个是 py-mysql-elasticsearch-sync,该工具是使用python语言编写,与go-mysql-elasticsearch的原理类似,都是利用binlog来实现数据的同步,安装及使用见官方文档https://github.com/zhongbiaodev/py-mysql-elasticsearch-sync; 另一个工具是logstash,使用logstash同步数据时需要安装logstash-input-jdbc、logstash-output-elasticsearch两个插件,具体使用参考官方文档:https://www.elastic.co/guide/en/logstash/current/plugins-inputs-jdbc.html 和 https://www.elastic.co/guide/en/logstash/current/plugins-outputs-elasticsearch.html
如果你在使用上述工具中遇到问题,欢迎联系我们。
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注意:ES7的type只能定义一种,或者直接使用_doc,这样处理只能是一个ES索引对应一个mysql的表