MySQL 與 Elasticsearch 數(shù)據(jù)不對稱問題解決辦法

更新時(shí)間：2017年08月24日 08:37:16 投稿：lqh

這篇文章主要介紹了MySQL 與 Elasticsearch 數(shù)據(jù)不對稱問題解決辦法的相關(guān)資料,對于 elasticsearch 增量寫入，但經(jīng)常jdbc源一端的數(shù)據(jù)庫可能會(huì)做數(shù)據(jù)庫刪除或者更新操作，這里提供解決辦法，需要的朋友可以參考下

MySQL 與 Elasticsearch 數(shù)據(jù)不對稱問題解決辦法

jdbc-input-plugin 只能實(shí)現(xiàn)數(shù)據(jù)庫的追加，對于 elasticsearch 增量寫入，但經(jīng)常jdbc源一端的數(shù)據(jù)庫可能會(huì)做數(shù)據(jù)庫刪除或者更新操作。這樣一來數(shù)據(jù)庫與搜索引擎的數(shù)據(jù)庫就出現(xiàn)了不對稱的情況。

當(dāng)然你如果有開發(fā)團(tuán)隊(duì)可以寫程序在刪除或者更新的時(shí)候同步對搜索引擎操作。如果你沒有這個(gè)能力，可以嘗試下面的方法。

這里有一個(gè)數(shù)據(jù)表 article , mtime 字段定義了 ON UPDATE CURRENT_TIMESTAMP 所以每次更新mtime的時(shí)間都會(huì)變化

mysql> desc article;
+-------------+--------------+------+-----+--------------------------------+-------+
| Field    | Type     | Null | Key | Default            | Extra |
+-------------+--------------+------+-----+--------------------------------+-------+
| id     | int(11)   | NO  |   | 0               |    |
| title    | mediumtext  | NO  |   | NULL              |    |
| description | mediumtext  | YES |   | NULL              |    |
| author   | varchar(100) | YES |   | NULL              |    |
| source   | varchar(100) | YES |   | NULL              |    |
| content   | longtext   | YES |   | NULL              |    |
| status   | enum('Y','N')| NO  |   | 'N'              |    |
| ctime    | timestamp  | NO  |   | CURRENT_TIMESTAMP       |    |
| mtime    | timestamp  | YES |   | ON UPDATE CURRENT_TIMESTAMP  |    |
+-------------+--------------+------+-----+--------------------------------+-------+
7 rows in set (0.00 sec)

logstash 增加 mtime 的查詢規(guī)則

jdbc {
  jdbc_driver_library => "/usr/share/java/mysql-connector-java.jar"
  jdbc_driver_class => "com.mysql.jdbc.Driver"
  jdbc_connection_string => "jdbc:mysql://localhost:3306/cms"
  jdbc_user => "cms"
  jdbc_password => "password"
  schedule => "* * * * *" #定時(shí)cron的表達(dá)式,這里是每分鐘執(zhí)行一次
  statement => "select * from article where mtime > :sql_last_value"
  use_column_value => true
  tracking_column => "mtime"
  tracking_column_type => "timestamp" 
  record_last_run => true
  last_run_metadata_path => "/var/tmp/article-mtime.last"
 }

創(chuàng)建回收站表，這個(gè)事用于解決數(shù)據(jù)庫刪除，或者禁用 status = 'N' 這種情況的。

CREATE TABLE `elasticsearch_trash` (
 `id` int(11) NOT NULL,
 `ctime` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
 PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

為 article 表創(chuàng)建觸發(fā)器

CREATE DEFINER=`dba`@`%` TRIGGER `article_BEFORE_UPDATE` BEFORE UPDATE ON `article` FOR EACH ROW
BEGIN
 -- 此處的邏輯是解決文章狀態(tài)變?yōu)?N 的時(shí)候，需要將搜索引擎中對應(yīng)的數(shù)據(jù)刪除。
 IF NEW.status = 'N' THEN
 insert into elasticsearch_trash(id) values(OLD.id);
 END IF;
 -- 此處邏輯是修改狀態(tài)到 Y 的時(shí)候，方式elasticsearch_trash仍然存在該文章ID，導(dǎo)致誤刪除。所以需要?jiǎng)h除回收站中得回收記錄。
  IF NEW.status = 'Y' THEN
 delete from elasticsearch_trash where id = OLD.id;
 END IF;
END

CREATE DEFINER=`dba`@`%` TRIGGER `article_BEFORE_DELETE` BEFORE DELETE ON `article` FOR EACH ROW
BEGIN
 -- 此處邏輯是文章被刪除同事將改文章放入搜索引擎回收站。
 insert into elasticsearch_trash(id) values(OLD.id);
END

接下來我們需要寫一個(gè)簡單地 Shell 每分鐘運(yùn)行一次，從 elasticsearch_trash 數(shù)據(jù)表中取出數(shù)據(jù)，然后使用 curl 命令調(diào)用 elasticsearch restful 接口，刪除被收回的數(shù)據(jù)。

你還可以開發(fā)相關(guān)的程序，這里提供一個(gè) Spring boot 定時(shí)任務(wù)例子。

實(shí)體

package cn.netkiller.api.domain.elasticsearch;

import java.util.Date;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table
public class ElasticsearchTrash {
 @Id
 private int id;

 @Column(columnDefinition = "TIMESTAMP DEFAULT CURRENT_TIMESTAMP")
 private Date ctime;

 public int getId() {
 return id;
 }

 public void setId(int id) {
 this.id = id;
 }

 public Date getCtime() {
 return ctime;
 }

 public void setCtime(Date ctime) {
 this.ctime = ctime;
 }

}

倉庫

package cn.netkiller.api.repository.elasticsearch;

import org.springframework.data.repository.CrudRepository;

import com.example.api.domain.elasticsearch.ElasticsearchTrash;

public interface ElasticsearchTrashRepository extends CrudRepository<ElasticsearchTrash, Integer>{


}

定時(shí)任務(wù)

package cn.netkiller.api.schedule;

import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.rest.RestStatus;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

import com.example.api.domain.elasticsearch.ElasticsearchTrash;
import com.example.api.repository.elasticsearch.ElasticsearchTrashRepository;

@Component
public class ScheduledTasks {
 private static final Logger logger = LoggerFactory.getLogger(ScheduledTasks.class);

 @Autowired
 private TransportClient client;

 @Autowired
 private ElasticsearchTrashRepository alasticsearchTrashRepository;

 public ScheduledTasks() {
 }

 @Scheduled(fixedRate = 1000 * 60) // 60秒運(yùn)行一次調(diào)度任務(wù)
 public void cleanTrash() {
 for (ElasticsearchTrash elasticsearchTrash : alasticsearchTrashRepository.findAll()) {
  DeleteResponse response = client.prepareDelete("information", "article", elasticsearchTrash.getId() + "").get();
  RestStatus status = response.status();
  logger.info("delete {} {}", elasticsearchTrash.getId(), status.toString());
  if (status == RestStatus.OK || status == RestStatus.NOT_FOUND) {
  alasticsearchTrashRepository.delete(elasticsearchTrash);
  }
 }
 }
}

Spring boot 啟動(dòng)主程序。

package cn.netkiller.api;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling;

@SpringBootApplication
@EnableScheduling
public class Application {

 public static void main(String[] args) {
 SpringApplication.run(Application.class, args);
 }
}

以上就是MySQL 與 Elasticsearch 數(shù)據(jù)不對稱問題解決辦法的講解，如有疑問請留言或者到本站社區(qū)交流討論，感謝閱讀，希望能幫助到大家，謝謝大家對本站的支持！

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