pm2日誌記錄和日誌分割

pm2介紹

pm2是nodejs進程管理工具，現在基本是node生產服務器的標準選擇，可以幫助我們實現node多進程服務，開啟的多個實例自動實現負載均衡。 最重要的是保證node單進程不會因為錯誤退出，作為守護進程保證nodejs服務不宕機。 總體來說就是有性能監控、自動重啟、負載均衡的作用。

pm2-logrotate介紹

pm2本身是可以輸出日誌文件的，默認的文件路徑：

error log path    │ /home/username/.pm2/logs/app-error-0.log
out log path      │ /home/username/.pm2/logs/app-out-0.log
 

但是pm2的日誌文件不能自動分割，這會導致一個文件不斷變大，不但影響性能，查看這些日誌也會帶來麻煩。所以需要pm2-logrotate來實現自動分割日誌。

安裝pm2-logrotate

pm2 install pm2-logrotate,是用pm2命令，不是npm命令

pm2-logrotate配置

• ``max_size` (默認 10M): 最大為多少時進行分割，例如: 10G, 10M, 10K
• ``retain` (Defaults to all): This number is the number of rotated logs that are keep at any one time, it means that if you have retain = 7 you will have at most 7 rotated logs and your current one.
• compress (默認 false): 是否壓縮日誌
• dateFormat (默認 YYYY-MM-DD_HH-mm-ss) : 日誌格式
• rotateModule (Defaults to true) : Rotate the log of pm2‘s module like other apps
• workerInterval (Defaults to 30 in secs) : You can control at which interval the worker is checking the log‘s size (minimum is 1)
• rotateInterval (Defaults to 0 0 * * * everyday at midnight): This cron is used to a force rotate when executed. We are using node-schedule to schedule cron, so all valid cron for node-schedule is valid cron for this option. Cron style :
• TZ (Defaults to system time): This is the standard tz database timezone used to offset the log file saved. For instance, a value of Etc/GMT-1, with an hourly log, will save a file at hour 14 GMT with hour 13 GMT-1 in the log name.

*    *    *    *    *    *
┬    ┬    ┬    ┬    ┬    ┬
│    │    │    │    │    |
│    │    │    │    │    └ day of week (0 - 7) (0 or 7 is Sun)
│    │    │    │    └───── month (1 - 12)
│    │    │    └────────── day of month (1 - 31)
│    │    └─────────────── hour (0 - 23)
│    └──────────────────── minute (0 - 59)
└───────────────────────── second (0 - 59, OPTIONAL)

可以嘗試使用pm2 set pm2-logrotate:max_size 1K (1KB)設置日誌文件最大為1KB 代碼中console.log的內容會輸出到 /home/username/.pm2/logs/app-out-0.log, 大小達到1KB就會自動生成 app-out-0__2018-01-25_16-58-16.log這種格式的日誌文件。 在/home/username/.pm2/logs/（默認路徑，可以配置）路徑下還有

• app-error-0.log
• pm2-logrotate-out-1.log
• pm2-logrotate-error-1.log 幾個文件，app-out-0.log文件記錄的就是console.log輸出，app-error-0.log記錄的是錯誤輸出，pm2-logrotate-out-1.log和pm2-logrotate-error-1.log分別記錄的是分割的日誌文件，是這樣的內容：

"/home/username/.pm2/pm2__2018-01-25_16-57-16.log" has been created
"/home/username/.pm2/logs/app-out-0__2018-01-25_16-58-16.log" has been created
"/home/username/.pm2/logs/app-out-0__2018-01-25_16-58-46.log" has been created

pm2日誌記錄和日誌分割