Monstache的安装和使用

一、什么是Monstache

Monstache 是Golang语言实现的基于MongoDB的oplog实现实时数据同步及订阅的插件，支持MongoDB与ES之间的数据同步。其中MongoDB需要搭建副本集。

二、安装过程

1、安装Go，并配置环境变量

(1) 下载Go并解压

wget https://dl.google.com/go/go1.14.4.linux-amd64.tar.gz  
tar -C /usr/local -xzf go1.14.4.linux-amd64.tar.gz  

(2) 建立go的工作空间，即GOAPTH所指向的目录

创建三个目录 mkdir bin、mkdir src、mkdir pkg

(3) 配置环境变量

使用 vim /etc/profile命令打开环境变量配置文件，并将如下内容写入该文件中。其中GOPROXY用来指定阿里云Go模块代理

export GOROOT=/usr/local/go  
export GOPATH=/home/go/  
export PATH=$PATH:$GOROOT/bin:$GOPATH/bin  
export GOPROXY=https://mirrors.aliyun.com/goproxy/  

(4) 应用环境变量配置

source /etc/profile  

2、Monstache说明

（1）Monstache-Mongodb-Es 版本关系:

Monstache version	Git branch (used to build plugin)	Docker tag	Description	Elasticsearch	MongoDB	Status
6	rel6	rel6, latest	MongoDB, Inc. go driver	Version 7+	Version 2.6+	Supported
5	rel5	rel5	MongoDB, Inc. go driver	Version 6	Version 2.6+	Supported
4	master	rel4	mgo community go driver	Version 6	Version 3	Deprecated
3	rel3	rel3	mgo community go driver	Versions 2 and 5	Version 3	Deprecated

（2）Monstache配置

参数	说明
mongo-url	MongoDB实例的主节点访问地址。可在实例的基本信息页面获取，获取前需配置MongoDB实例的白名单，即在白名单中添加安装Monstache的ECS实例的内网IP地址。
elasticsearch-urls	Elasticsearch实例的访问地址，格式为http://<Elasticsearch实例的内网地址>:9200。
direct-read-namespaces	指定待同步的集合
change-stream-namespaces	如果要使用MongoDB变更流功能，需要指定此参数。启用此参数后，oplog追踪会被设置为无效
namespace-regex	通过正则表达式指定需要监听的集合。此设置可以用来监控符合正则表达式的集合中数据的变化。
elasticsearch-user	访问Elasticsearch实例的用户名，默认为elastic。 注意 实际业务中不建议使用elastic用户，这样会降低系统安全性。建议使用自建用户，并给予自建用户分配相应的角色和权限。
elasticsearch-password	对应用户的密码。elastic用户的密码在创建实例时指定，如果忘记可进行重置
elasticsearch-max-conns	定义连接Elasticsearch的线程数。默认为4，即使用4个Go线程同时将数据同步到Elasticsearch。
dropped-collections	默认为true，表示当删除MongoDB集合时，会同时删除Elasticsearch中对应的索引。
dropped-databases	默认为true，表示当删除MongoDB数据库时，会同时删除Elasticsearch中对应的索引。
resume	默认为false。设置为true，Monstache会将已成功同步到Elasticsearch的MongoDB操作的时间戳写入monstache.monstache集合中。当Monstache因为意外停止时，可通过该时间戳恢复同步任务，避免数据丢失。如果指定了cluster-name，该参数将自动开启。
resume-strategy	指定恢复策略。仅当resume为true时生效。
verbose	默认为false，表示不启用调试日志。
cluster-name	指定集群名称。指定后，Monstache将进入高可用模式，集群名称相同的进程将进行协调
mapping	指定Elasticsearch索引映射。默认情况下，数据从MongoDB同步到Elasticsearch时，索引会自动映射为数据库名.集合名。如果需要修改索引名称，可通过该参数设置。

3、Monstache安装

（1）进入安装路径

cd /usr/local

（2）使用命令下载或手动上传安装包

1）从git库下载

git clone https://github.com/rwynn/monstache.git，若提示下载失败需先下载git ,使用yum install -y git命令

2）手动上传

资源下载地址: https://github.com/rwynn/monstache

进入安装目录，安装

cd /usr/local/monstache-6.7.11
go install

查看版本

安装完成

4、配置实时同步任务

（1）进入Monstache安装目录，创建并编辑配置文件

#创建monstache的存储目录
cd /usr/local/monstache-6.7.11
mkdir config
mkdir logs

进入config目录，编辑创建配置文件

cd config
vim config.toml  

文件内容如下

# connection settings  

# connect to MongoDB using the following URL
mongo-url = "mongodb://192.168.8.79:27017/pns"

# connect to the Elasticsearch REST API at the following node URLs
elasticsearch-urls = ["http://192.168.8.153:9200"]  

# frequently required settings  

# if you need to seed an index from a collection and not just listen and sync changes events
# you can copy entire collections or views from MongoDB to Elasticsearch
direct-read-namespaces = ["库名.集合名"]  

# if you want to use MongoDB change streams instead of legacy oplog tailing use change-stream-namespaces
# change streams require at least MongoDB API 3.6+
# if you have MongoDB 4+ you can listen for changes to an entire database or entire deployment
# in this case you usually don't need regexes in your config to filter collections unless you target the deployment.
# to listen to an entire db use only the database name.  For a deployment use an empty string.
#change-stream-namespaces = ["mydb.col"]  

# additional settings  

# if you don't want to listen for changes to all collections in MongoDB but only a few
# e.g. only listen for inserts, updates, deletes, and drops from mydb.mycollection
# this setting does not initiate a copy, it is only a filter on the change event listener
namespace-regex = '^库名\.集合名$'
# compress requests to Elasticsearch
gzip = true
# generate indexing statistics
#stats = true
# index statistics into Elasticsearch
#index-stats = true
# use the following PEM file for connections to MongoDB
#mongo-pem-file = "/path/to/mongoCert.pem"
# disable PEM validation
#mongo-validate-pem-file = false
# use the following user name for Elasticsearch basic auth
elasticsearch-user = "elastic"
# use the following password for Elasticsearch basic auth
elasticsearch-password = "<your_es_password>"
# use 4 go routines concurrently pushing documents to Elasticsearch
elasticsearch-max-conns = 4
# use the following PEM file to connections to Elasticsearch
#elasticsearch-pem-file = "/path/to/elasticCert.pem"
# validate connections to Elasticsearch
#elastic-validate-pem-file = true
# propogate dropped collections in MongoDB as index deletes in Elasticsearch
dropped-collections = true
# propogate dropped databases in MongoDB as index deletes in Elasticsearch
dropped-databases = true
# do not start processing at the beginning of the MongoDB oplog
# if you set the replay to true you may see version conflict messages
# in the log if you had synced previously. This just means that you are replaying old docs which are already
# in Elasticsearch with a newer version. Elasticsearch is preventing the old docs from overwriting new ones.
#replay = false
# resume processing from a timestamp saved in a previous run
resume = true
# do not validate that progress timestamps have been saved
#resume-write-unsafe = false
# override the name under which resume state is saved
#resume-name = "default"
# use a custom resume strategy (tokens) instead of the default strategy (timestamps)
# tokens work with MongoDB API 3.6+ while timestamps work only with MongoDB API 4.0+
resume-strategy = 0
# exclude documents whose namespace matches the following pattern
#namespace-exclude-regex = '^mydb\.ignorecollection$'
# turn on indexing of GridFS file content
#index-files = true
# turn on search result highlighting of GridFS content
#file-highlighting = true
# index GridFS files inserted into the following collections
#file-namespaces = ["users.fs.files"]
# print detailed information including request traces
verbose = true
# enable clustering mode
#cluster-name = 'es-cn-mp91kzb8m00******'
# do not exit after full-sync, rather continue tailing the oplog
#exit-after-direct-reads = false
[[mapping]]
namespace = "pns.user_device_table"
index = "pns.user_device_table"
#type = "device"  

注：1）如果不设置mapping，那么同步到es的索引默认为mongoDB的数据库名.集合名

2）monstache是根据mongoDB的oplog来同步更新的，因此需要开启mongo的副本集才可以

3）当mongo有密码认证时mongoUrl需要改为

mongodb://用户：密码@IP:PORT/数据库名称?authSource=数据库名称&authMechanism=SCRAM-SHA-1，同时这个地址要为mongoDB主节点访问地址

4）direct-read-namespaces表示初始化会全量同步到es，而change-stream-namespaces只会同步有更改变化的

5）namespace-regex不设置时默认同步mongoDB中所有数据的更改变化，可以指定只同步哪个或哪些集合的增删改

（2）配置自启

#切换目录
cd /etc/init.d  

#编辑命令
vim monstache  

脚本内容

#!/bin/bash
#
# chkconfig: 2345 10 90
#
# description: MONSTACHE RUN  

#程序名
MONSTACHE_NAME="monstache-rel6"  

#资源位置
MONSTACHE_OPTS=/home/go/bin/monstache
MONSTACHE_CONF=/usr/local/monstache-6.7.11/config/config.toml  

#日志位置
MONSTACHE_LOGS=/usr/local/monstache-6.7.11/logs/monstache.log  

#开始方法
start() {
nohup $MONSTACHE_OPTS -f $MONSTACHE_CONF > $MONSTACHE_LOGS  2>&1 &
echo "$MONSTACHE_NAME started success."
}  

#结束方法
stop() {
echo "stopping $MONSTACHE_NAME ..."
kill -9 `ps -ef|grep $MONSTACHE_OPTS|grep -v grep|grep -v stop|awk '{print $2}'`
}  

case "$1" in
start)
start
;;
stop)
stop
;;
restart)
stop
start
;;
*)
echo "Userage: $0 {start|stop|restart}"
exit 1
esac  

#授权
chmod +x monstache   

#添加系统服务
chkconfig --add monstache
chkconfig monstache on
chkconfig --list  

注：MONSTACHE_OPTS位置是在GO的安装目录下

（3）启停相关

#启停命令
systemctl start|stop|restart monstache  

#查看进程
ps -ef|grep monstache  

注：

　　1、使用版本

　　　　mongo 4.4.15

　　　　monstache 6.7.11

　　　　elasticsearch 7.9.2

　　2、mongo单机创建副本集

　　　　参考文档：http://www.kaotop.com/it/14307.html

　　3、集群下创建副本集

　　　　参考文档：https://blog.csdn.net/qq_42428264/article/details/124227050

参考原文地址：https://blog.csdn.net/weixin_44187730/article/details/117198268