小步快跑的公司可以最简化操作直接通过log4net将日志写入ElasticSearch

　　　　　　　　　　　　

　　 很多小步快跑的公司，开发人员多则3-4个，面对巨大业务压力，日连夜的赶着上线，快速试错，自然就没时间搭建一些基础设施，比如说logCenter，但初期

项目不稳定，bug又多，每次都跑到生产去找日志，确实也不大方便，用elk或者用hadoop做日志中心，虽然都是没问题的，但基于成本和人手还是怎么简化怎么来，

本篇就来说说直接使用log4net的ElasticSearchAppender扩展直接将log写入到es中。

　　

一：从nuget下载

　   nuget下来的都是开箱可用，如果看源码的话可以在github上找一下log4net.ElasticSearch项目。。

在浏览器中加载插件的时候选择0.1.3.0 文件夹即可

 

完了之后点击右上边的 “放大镜“ 按钮就可以看到你想看到的UI了。

 

三：下载elasticsearch

　　这是一个基于luncene的分布式搜索框架，用起来还是挺顺手的，你可以下载5.6.4版本。

[elsearch@localhost myapp]$ ls
elasticsearch-5.6.4.tar.gz  

 

　　一般来说，安装的过程中你可能会遇到3个坑。

 

1.  不能用root账号登录

[root@localhost bin]# ./elasticsearch
[2018-05-31T04:01:59,402][WARN ][o.e.b.ElasticsearchUncaughtExceptionHandler] [] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.RuntimeException: can not run elasticsearch as root
    at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:136) ~[elasticsearch-5.6.4.jar:5.6.4]
    at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:123) ~[elasticsearch-5.6.4.jar:5.6.4]
    at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:70) ~[elasticsearch-5.6.4.jar:5.6.4]
    at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:134) ~[elasticsearch-5.6.4.jar:5.6.4]
    at org.elasticsearch.cli.Command.main(Command.java:90) ~[elasticsearch-5.6.4.jar:5.6.4]
    at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:91) ~[elasticsearch-5.6.4.jar:5.6.4]
    at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:84) ~[elasticsearch-5.6.4.jar:5.6.4]
Caused by: java.lang.RuntimeException: can not run elasticsearch as root
    at org.elasticsearch.bootstrap.Bootstrap.initializeNatives(Bootstrap.java:106) ~[elasticsearch-5.6.4.jar:5.6.4]
    at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:195) ~[elasticsearch-5.6.4.jar:5.6.4]
    at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:342) ~[elasticsearch-5.6.4.jar:5.6.4]
    at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:132) ~[elasticsearch-5.6.4.jar:5.6.4]
    ... 6 more

 

        这个简单，增加一个elasearch用户就可以了。

groupadd elsearch                   #新建elsearch组
useradd elsearch -g elsearch -p elasticsearch  #新建一个elsearch用户
chown -R elsearch:elsearch  ./elasticsearch    #指定elasticsearch所属elsearch组

 

2.  内存不足的问题。

[elsearch@localhost bin]$ ./elasticsearch
Java HotSpot(TM) 64-Bit Server VM warning: INFO: os::commit_memory(0x00000000a9990000, 1449590784, 0) failed; error='Cannot allocate memory' (errno=12)
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 1449590784 bytes for committing reserved memory.
# An error report file with more information is saved as:
# /usr/myapp/elasticsearch/bin/hs_err_pid33341

 

      这是ES默认分配的堆内存是2g，如果出现这个问题，一般来说是你的虚拟机拥有的内存小于2g，只需要在jvm.options中将2g修改1g就可以了。

[root@localhost config]# ls
elasticsearch.yml  jvm.options  log4j2.properties  scripts

# Xms represents the initial size of total heap space
# Xmx represents the maximum size of total heap space

-Xms1g
-Xmx1g

 

3. max file descriptors 太少 和 max virtual memory 虚拟内存太低。

[elsearch@localhost bin]$ ./elasticsearch
[2018-05-30T20:44:56,484][INFO ][o.e.n.Node               ] [] initializing ...
[2018-05-30T20:44:56,632][INFO ][o.e.e.NodeEnvironment    ] [f9t2Sfl] using [1] data paths, mounts [[/ (rootfs)]], net usable_space [14.4gb], net total_space [22.1gb], spins? [unknown], types [rootfs]
[2018-05-30T20:44:56,632][INFO ][o.e.e.NodeEnvironment    ] [f9t2Sfl] heap size [989.8mb], compressed ordinary object pointers [true]
[2018-05-30T20:44:56,634][INFO ][o.e.n.Node               ] node name [f9t2Sfl] derived from node ID [f9t2SfljReiND4XeMLUbyA]; set [node.name] to override
[2018-05-30T20:44:56,634][INFO ][o.e.n.Node               ] version[5.6.4], pid[33546], build[8bbedf5/2017-10-31T18:55:38.105Z], OS[Linux/3.10.0-327.el7.x86_64/amd64], JVM[Oracle Corporation/Java HotSpot(TM) 64-Bit Server VM/1.8.0_144/25.144-b01]
[2018-05-30T20:44:56,634][INFO ][o.e.n.Node               ] JVM arguments [-Xms1g, -Xmx1g, -XX:+UseConcMarkSweepGC, -XX:CMSInitiatingOccupancyFraction=75, -XX:+UseCMSInitiatingOccupancyOnly, -XX:+AlwaysPreTouch, -Xss1m, -Djava.awt.headless=true, -Dfile.encoding=UTF-8, -Djna.nosys=true, -Djdk.io.permissionsUseCanonicalPath=true, -Dio.netty.noUnsafe=true, -Dio.netty.noKeySetOptimization=true, -Dio.netty.recycler.maxCapacityPerThread=0, -Dlog4j.shutdownHookEnabled=false, -Dlog4j2.disable.jmx=true, -Dlog4j.skipJansi=true, -XX:+HeapDumpOnOutOfMemoryError, -Des.path.home=/usr/myapp/elasticsearch]
[2018-05-30T20:44:57,530][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [aggs-matrix-stats]
[2018-05-30T20:44:57,530][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [ingest-common]
[2018-05-30T20:44:57,530][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [lang-expression]
[2018-05-30T20:44:57,531][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [lang-groovy]
[2018-05-30T20:44:57,531][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [lang-mustache]
[2018-05-30T20:44:57,531][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [lang-painless]
[2018-05-30T20:44:57,531][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [parent-join]
[2018-05-30T20:44:57,531][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [percolator]
[2018-05-30T20:44:57,531][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [reindex]
[2018-05-30T20:44:57,531][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [transport-netty3]
[2018-05-30T20:44:57,531][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [transport-netty4]
[2018-05-30T20:44:57,532][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] no plugins loaded
[2018-05-30T20:44:59,469][INFO ][o.e.d.DiscoveryModule    ] [f9t2Sfl] using discovery type [zen]
[2018-05-30T20:45:00,107][INFO ][o.e.n.Node               ] initialized
[2018-05-30T20:45:00,107][INFO ][o.e.n.Node               ] [f9t2Sfl] starting ...
[2018-05-30T20:45:00,339][INFO ][o.e.t.TransportService   ] [f9t2Sfl] publish_address {192.168.23.143:9300}, bound_addresses {[::]:9300}
[2018-05-30T20:45:00,356][INFO ][o.e.b.BootstrapChecks    ] [f9t2Sfl] bound or publishing to a non-loopback or non-link-local address, enforcing bootstrap checks
ERROR: [2] bootstrap checks failed
[1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65536]
[2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]
[2018-05-30T20:45:00,365][INFO ][o.e.n.Node               ] [f9t2Sfl] stopping ...
[2018-05-30T20:45:00,444][INFO ][o.e.n.Node               ] [f9t2Sfl] stopped
[2018-05-30T20:45:00,444][INFO ][o.e.n.Node               ] [f9t2Sfl] closing ...
[2018-05-30T20:45:00,455][INFO ][o.e.n.Node               ] [f9t2Sfl] closed

 

  　　这个max file descriptors 的问题，我只需要修改 vim /etc/security/limits.conf 文件增加句柄值即可。

* hard nofile 65536
* soft nofile 65536

 

 虚拟内存的 max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]  只需要在sysctl.conf 中修改max即可。

[root@localhost config]# vim /etc/sysctl.conf

vm.max_map_count=655360

 

     这些坑解决的话，es就可以正常启动了，最后记得在elasticsearch.yml 中将host设为0.0.0.0 让远程机器可以访问。

[elsearch@localhost config]$ vim elasticsearch.yml

network.host: 0.0.0.0

    最后执行 ./elasticsearch -d  让es在后台执行。

[elsearch@localhost bin]$ ./elasticsearch -d

[elsearch@localhost bin]$ netstat -tlnp
(Not all processes could be identified, non-owned process info
 will not be shown, you would have to be root to see it all.)
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 192.168.122.1:53        0.0.0.0:*               LISTEN      -                   
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      -                   
tcp        0      0 127.0.0.1:631           0.0.0.0:*               LISTEN      -                   
tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      -                   
tcp6       0      0 :::9200                 :::*                    LISTEN      17523/java          
tcp6       0      0 :::9300                 :::*                    LISTEN      17523/java          
tcp6       0      0 :::22                   :::*                    LISTEN      -                   
tcp6       0      0 ::1:631                 :::*                    LISTEN      -                   
tcp6       0      0 ::1:25                  :::*                    LISTEN      -                   
[elsearch@localhost bin]$ 

 

      好了，本篇就说这么多，如果你要更精细化的查询，可以再搭建一个配套版本的kibana即可。