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。https://github.com/jptoto/log4net.ElasticSearch。

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

1. App.config配置

nuget包下来之后,就可以配置config文件了,其实还是蛮简单的,大家可以根据自己的项目合理的配置里面的各项参数,为了方便大家理解,我在每个配置

项上加了详细的注释,大家可以仔细看看。

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <configSections>
        <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
    </configSections>
    <log4net>
        <!-- 日志的处理类:log4net.ElasticSearch.ElasticSearchAppender -->
        <appender name="ElasticSearchAppender" type="log4net.ElasticSearch.ElasticSearchAppender, log4net.ElasticSearch">

            <!-- ES地址  rolling=true:表示每天一个index(datamipcrm_log_2018.05.31)  -->
            <connectionString value="Scheme=http;Server=192.168.23.145;Index=datamiprm_log;Port=9200;rolling=true"/>
            <!-- 有损配置: 如果配置的buffer满了还没来的及刷新到es中,那么新来的log将会被丢弃。 -->
            <lossy value="false" />
            <evaluator type="log4net.Core.LevelEvaluator">
                <!--
                    表示 小于ERROR级别的日志会进入buffer数组,大于等于这个级别的,直接提交给es。
                    通常情况下,ERROR级别的错误,我们直接塞到ES中,这样更有利于我们发现问题。 DEBUG,INFO WARN ERROR -->
                <threshold value="ERROR" />
            </evaluator>
            
            <!-- buffer池的阈值50,一旦满了就会触发flush 到 es的动作(bulk api) -->
            <bufferSize value="50" />
        </appender>
        <root>
            <!-- 指定所有的loglevel(DEBUG,INFO,WARN,ERROR)级别都是用 ElasticSearchAppender 处理 -->
            <level value="ALL"/>
            <appender-ref ref="ElasticSearchAppender" />
        </root>
    </log4net>
    <startup>
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
    </startup>
</configuration>

上面有几点要特别注意一下:

《1》 bufferSize

这个大家理解成缓存区,方便批量提交到es中,否则的话,过于频繁的和es进行交互,对带宽,对application,es都是比较大的压力。

《2》 <threshold value="ERROR" />

有时候我们有这样的需求,我希望ERROR,Fault这种级别的错误不要走buffer,直接提交给es,这样更容易让初创团队发现问题,找到问题,恭喜你,

上面这个配置就是解决这个事的。

2. 在AssemblyInfo中追加如下配置。

// 可以指定所有值,也可以使用以下所示的 "*" 预置版本号和修订号
// 方法是按如下所示使用“*”: :
// [assembly: AssemblyVersion("1.0.*")]
[assembly: AssemblyVersion("1.0.0.0"<span>)]
[assembly: AssemblyFileVersion("1.0.0.0"<span>)]
[assembly: log4net.Config.XmlConfigurator(Watch = true)]

3. 然后就可以写一段测试代码啦。

namespace ConsoleApp1
{
    class Program
    {
        private static readonly ILog _log = LogManager.GetLogger(typeof(Program));

        static void Main(string[] args)
        {<br /><br />           for (int i = 0; i < 1000; i++)
            {
                try
                {
                    var m = "1";

                    var result = 100 / Convert.ToInt32(m);
                    _log.Info("我要开始记录日志啦");

                }
                catch (Exception ex)
                {
                    _log.Error("调用失败" + i, ex);
                    //_log.Info("调用失败" + i, ex);
                    //Console.WriteLine(i);
                }
            }

            Console.Read();
        }

    }
}

然后通过elasticsearch-head 插件进行查看,各种数据就都在es中了。

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

二:elasticsearch-header 插件

关于这个插件的下载,因为google官网被屏蔽,大家如果有VPN的话,可以自行在chrome商店搜索,当然也可以直接下载我的zip包,elasticsearch-head。

在浏览器中加载插件的时候选择0.1.3.0 文件夹即可

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

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。

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

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..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]$ ./<span>elasticsearch
Java HotSpot(TM) 64-Bit Server VM warning: INFO: os::commit_memory(0x00000000a9990000, 1449590784, 0) failed; error='Cannot allocate memory' (errno=12<span>)
#
# There is insufficient memory for<span> the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 1449590784 bytes for<span> committing reserved memory.
# An error report file with more<span> 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]$ ./<span>elasticsearch
[2018-05-30T20:44:56,484<span>][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?<span> [unknown], types [rootfs]
[2018-05-30T20:44:56,632][INFO ][o.e.e.NodeEnvironment    ] [f9t2Sfl] heap size [989.8mb], compressed ordinary object pointers [true<span>]
[2018-05-30T20:44:56,634<span>][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-<span>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/<span>elasticsearch]
[2018-05-30T20:44:57,530][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [aggs-matrix-<span>stats]
[2018-05-30T20:44:57,530][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [ingest-<span>common]
[2018-05-30T20:44:57,530][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [lang-<span>expression]
[2018-05-30T20:44:57,531][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [lang-<span>groovy]
[2018-05-30T20:44:57,531][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [lang-<span>mustache]
[2018-05-30T20:44:57,531][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [lang-<span>painless]
[2018-05-30T20:44:57,531][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [parent-join<span>]
[2018-05-30T20:44:57,531<span>][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [percolator]
[2018-05-30T20:44:57,531<span>][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [reindex]
[2018-05-30T20:44:57,531][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [transport-<span>netty3]
[2018-05-30T20:44:57,531][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] loaded module [transport-<span>netty4]
[2018-05-30T20:44:57,532<span>][INFO ][o.e.p.PluginsService     ] [f9t2Sfl] no plugins loaded
[2018-05-30T20:44:59,469<span>][INFO ][o.e.d.DiscoveryModule    ] [f9t2Sfl] using discovery type [zen]
[2018-05-30T20:45:00,107<span>][INFO ][o.e.n.Node               ] initialized
[2018-05-30T20:45:00,107<span>][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<span>}
[2018-05-30T20:45:00,356][INFO ][o.e.b.BootstrapChecks    ] [f9t2Sfl] bound or publishing to a non-loopback or non-link-<span>local address, enforcing bootstrap checks
ERROR: [2<span>] bootstrap checks failed
[1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65536<span>]
[2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144<span>]
[2018-05-30T20:45:00,365<span>][INFO ][o.e.n.Node               ] [f9t2Sfl] stopping ...
[2018-05-30T20:45:00,444<span>][INFO ][o.e.n.Node               ] [f9t2Sfl] stopped
[2018-05-30T20:45:00,444<span>][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
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

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=

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 -<span>d

[elsearch@localhost bin]$ netstat -<span>tlnp
(Not all processes could be identified, non-owned process info<span>
 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/<span>Program name    
tcp        0      0 192.168.122.1:53        0.0.0.0:*               LISTEN      -<span>                   
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      -<span>                   
tcp        0      0 127.0.0.1:631           0.0.0.0:*               LISTEN      -<span>                   
tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      -<span>                   
tcp6       0      0 :::9200                 :::*                    LISTEN      17523/<span>java          
tcp6       0      0 :::9300                 :::*                    LISTEN      17523/<span>java          
tcp6       0      0 :::22                   :::*                    LISTEN      -<span>                   
tcp6       0      0 ::1:631                 :::*                    LISTEN      -<span>                   
tcp6       0      0 ::1:25                  :::*                    LISTEN      -<span>                   
[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。