There are a lot of logs in the Linux server. How to read the logs correctly and quickly locate errors?-Linux Operation and Maintenance-php.cn

Quickly locate the wrong place for a large number of logs

There are a lot of logs in the Linux server. How to read the logs correctly and quickly locate errors?

View the log dynamically

tail -f catalina.out

Copy after login

Open the log file from the beginning

cat catalina.out

Copy after login

You can use >nanjiangtest.txt to output a new log to view

[root@yesky logs]# cat -n catalina.out |grep 717892466 >nanjiangtest.txt

Copy after login

tail/ Use the simple head command:

[root@yesky logs]# tail -n number catalina.out 查询日志尾部最后number行的日志[root@yesky logs]# tail -n +number catalina.out 查询number行之后的所有日志[root@yesky logs]# head -n number catalina.out 查询日志文件中的前number行日志[root@yesky logs]# head -n -number catalina.out 查询日志文件除了最后number行的其他所有日志

Copy after login

The first way (find the trip number based on keywords):

Using grep to get very few logs, we Need to check nearby logs. This is what I did, first: cat -n test.log | grep "keyword" to get the line number of the key log

[root@yesky logs]# cat -n catalina.out |grep 71789246613230539 [11:07 17:47:11] INFO nanjiang:Edit Old Article：717892466-2020-11-07 17:47:1113230593 [11:07 17:47:15] INFO nanjiangSave Article ID IS：71789246613230595 717892466 article.getDisplayTime()1 = 2020-11-07 16:25:1113230596 717892466 article.getDisplayTime()2 = 2020-11-07 16:25:1113230601 [11:07 17:47:15] INFO 南江 10.10.10.39 edit article 717892466 编辑文章

Copy after login

cat -n catalina.out|tail -n 13230539|head -n 10

tail -n 13230539 means querying the log after line 13230539
head -n 10 means querying the log after 13230539 lines Check the first 10 records in the previous query results

[root@yesky logs]# cat -n catalina.out |tail -n +13230539|head -n 1013230539 [11:07 17:47:11] INFO nanjiang:Edit Old Article：717892466-2020-11-07 17:47:1113230540 [11:07 17:47:11] INFO Takes:2 ms class com.tmg.cms.manager.dao.article.impl.ArticleContentDaoImpl getListByArticleId [NzE3ODkyNDY2] [int]13230541 [11:07 17:47:11] INFO Takes:1 ms class com.tmg.cms.manager.dao.resourceImage.impl.ResourceImageDaoImpl load 13230542 [11:07 17:47:11] INFO Takes:0 ms class com.tmg.cms.manager.dao.resourceImage.impl.ResourceImageDaoImpl load 13230543 [11:07 17:47:11] INFO Takes:1 ms class com.tmg.cms.manager.dao.resourceImage.impl.ResourceImageDaoImpl load 13230544 [11:07 17:47:11] INFO article.getImage3：/uploadImages/2020/312/02/3NXCRK4U3589_2.jpg13230545 [11:07 17:47:11] INFO Takes:0 ms class com.tmg.cms.manager.dao.resourceImage.impl.ResourceImageDaoImpl load 13230546 [11:07 17:47:11] INFO Takes:2 ms class com.tmg.cms.manager.dao.privilege.impl.UserDaoImpl getUserByid 13230547 [11:07 17:47:11] INFO Takes:57 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl selectSitemapWithoutAudit [MQ==] [int]13230548 [11:07 17:47:11] INFO Takes:5 ms class com.tmg.cms.manager.dao.forbidword.impl.ForbidwordDaoImpl getForbidwordBysiteid [MjI=] [int]

Copy after login

Second method: View the logs within the specified time period

First, perform a log query within the range time period and first check whether there is a query within the current day.

grep '11:07 18:29:20' catalina.outgrep '11:07 18:31:11' catalina.out

Copy after login

Query within the time range

sed -n '/11:07 18:29:20/,/11:07 18:31:11/p' catalina.out sed -n '/11:07 18:29:/,/11:07 18:31:/p' catalina.out

Copy after login

第三种方式：查看日志中特定字符的匹配数目

[root@yesky logs]# grep '1175109632' catalina.out | wc -l154

Copy after login

第四种方式：查询最后number行，并查找关键字“结果”

[root@yesky logs]# tail -n 20 catalina.out | grep 'INFO Takes:1'[11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.config.impl.ConfigInfoDaoImpl load [11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [NTkwOTQ5] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzI0] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzI3] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzMw] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzA5NA==] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [Mzc4Mg==] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [OTM1MA==] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MTE5MDMw] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [NTQ2MzQw] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [NTg2NzYy] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzYyMjA=] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.configModule.impl.ConfigModuleDaoImpl getPersonMenuList

Copy after login

第五种方式：查询最后number行，并查找关键字“结果”并且对结果进行标红

[root@yesky logs]# tail -n 20 catalina.out | grep 'INFO Takes:1' --color[11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.config.impl.ConfigInfoDaoImpl load [11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [NTkwOTQ5] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzI0] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzI3] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzMw] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzA5NA==] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [Mzc4Mg==] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [OTM1MA==] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MTE5MDMw] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [NTQ2MzQw] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [NTg2NzYy] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzYyMjA=] [int]

Copy after login

第六种方式：查询最后number行，并查找关键字“结果”并且对结果进行标红，上下扩展两行

[root@yesky logs]# tail -n 20 catalina.out | grep 'INFO Takes:1' --color -a2[11:11 22:02:51] INFO Takes:0 ms class com.tmg.cms.manager.dao.article.impl.ArticleContentDaoImpl getArticlePageNum [NzE4MTM2ODky] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.config.impl.ConfigInfoDaoImpl load [com.tmg.cms.manager.model.config.ConfigInfo][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [NTkwOTQ5] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzI0] [int][11:11 22:02:51] INFO Takes:0 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzI1] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzI3] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzMw] [int][11:11 22:02:51] INFO Takes:0 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzAzNg==] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzA5NA==] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [Mzc4Mg==] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [OTM1MA==] [int][11:11 22:02:51] INFO Takes:0 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MTE0MjQ4] [int][11:11 22:02:51] INFO Takes:0 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MTE4MDc4] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MTE5MDMw] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [NTQ2MzQw] [int][11:11 22:02:51] INFO Takes:0 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [NTQ3MTIw] [int][11:11 22:02:51] INFO Takes:0 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [NTY4OTYx] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [NTg2NzYy] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.sitemap.impl.SitemapDaoImpl getSitemapTop [MzYyMjA=] [int][11:11 22:02:51] INFO Takes:1 ms class com.tmg.cms.manager.dao.configModule.impl.ConfigModuleDaoImpl getPersonMenuList [com.tmg.cms.manager.model.config.ConfigPersonMenu]

Copy after login

第七种方式：分页查看，使用空格翻页(使用more/less)

[root@yesky logs]# tail -n 2000 catalina.out | grep 'INFO Takes:1' --color -a2 | more[root@yesky logs]# tail -n 2000 catalina.out | grep 'INFO Takes:1' --color -a2 | less

Copy after login

附加：

全屏导航
ctrl + F - 向前移动一屏
ctrl + B - 向后移动一屏
ctrl + D - 向前移动半屏
ctrl + U - 向后移动半屏
单行导航
j - 向前移动一行
k - 向后移动一行
其它导航
G - 移动到最后一行
g - 移动到第一行
q / ZZ - 退出 less 命令

The above is the detailed content of There are a lot of logs in the Linux server. How to read the logs correctly and quickly locate errors?. For more information, please follow other related articles on the PHP Chinese website!