openGauss每日一练第1天 | 学习心得体会

gs_ctl是openGauss提供的数据库服务控制工具，可以用来启停数据库服务和查询数据库状态。主要供openGauss管理模块调用。

gs_ctl工具由操作系统用户omm执行。可以执行：启动、停止、重启openGauss节点。

#su - omm

1.操作系统层面查看数据库进程和线程。如果数据库启动，则有相应的进程和线程。

操作系统层面查看数据库进程：

omm@modb:~$ omm@modb:~$ ps -ef|grep gauss
omm          1     0  0 11:48 ?        00:00:04 gaussdb
omm        505   468  0 12:07 pts/0    00:00:00 grep gauss

操作系统层面查看数据库线程：

omm@modb:~$ ps -Tp 1
  PID  SPID TTY          TIME CMD
    1     1 ?        00:00:00 gaussdb
    1   299 ?        00:00:00 gaussdb
    1   300 ?        00:00:00 syslogger
    1   293 ?        00:00:00 jemalloc_bg_thd
    1   301 ?        00:00:00 jemalloc_bg_thd
    1   302 ?        00:00:00 alarm
    1   303 ?        00:00:00 reaper
    1   304 ?        00:00:00 jemalloc_bg_thd
    1   305 ?        00:00:00 jemalloc_bg_thd
    1   349 ?        00:00:00 checkpointer
    1   350 ?        00:00:00 Spbgwriter
    1   351 ?        00:00:00 pagewriter
    1   352 ?        00:00:00 pagewriter
    1   353 ?        00:00:00 pagewriter
    1   354 ?        00:00:00 pagewriter
    1   355 ?        00:00:00 pagewriter
    1   356 ?        00:00:00 WALwriter
    1   357 ?        00:00:00 WALwriteraux
    1   358 ?        00:00:00 AVClauncher
    1   359 ?        00:00:00 Jobscheduler
    1   360 ?        00:00:00 asyncundolaunch
    1   361 ?        00:00:00 globalstats
    1   362 ?        00:00:00 applylauncher
    1   363 ?        00:00:00 statscollector
    1   364 ?        00:00:00 percentworker
    1   365 ?        00:00:02 ashworker
    1   366 ?        00:00:00 TrackStmtWorker
    1   367 ?        00:00:00 auditor
    1   368 ?        00:00:00 2pccleaner
    1   369 ?        00:00:00 faultmonitor
    1   370 ?        00:00:00 WLMworker
    1   371 ?        00:00:00 WLMmonitor
    1   372 ?        00:00:00 WLMarbiter
    1   373 ?        00:00:00 undorecycler

2.使用gs_ctl工具查看数据库状态，如果数据库启动，显示gs_ctl: server is running (PID: 1)

omm@modb:~$ gs_ctl status
[2022-11-24 12:12:35.717][524][][gs_ctl]: gs_ctl status,datadir is /var/lib/opengauss/data 
gs_ctl: server is running (PID: 1)
/usr/local/opengauss/bin/gaussdb

3.使用gs_ctl 查看数据文件的目录

omm@modb:~$ gs_ctl notify
[2022-11-24 12:14:42.072][537][][gs_ctl]: gs_ctl notify ,datadir is /var/lib/opengauss/data 
[2022-11-24 12:14:42.073][537][][gs_ctl]: the parameter of notify must be specified
omm@modb:~$ 

4.查看omm用户的环境变量

omm@modb:~$ cat ~/.bashrc
# ~/.bashrc: executed by bash(1) for non-login shells.
# see /usr/share/doc/bash/examples/startup-files (in the package bash-doc)
# for examples

# If not running interactively, don't do anything
case $- in
    *i*) ;;
      *) return;;
esac

# don't put duplicate lines or lines starting with space in the history.
# See bash(1) for more options
HISTCONTROL=ignoreboth
...

5.从环境变量查看数据文件的目录

omm@modb:~$ grep -i PGDATA ~/.bashrc
export PGDATA=/var/lib/opengauss/data

6.在gsql中查看数据文件的目录、数据库版本

查看数据库版本：

omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr  )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.

数据文件的目录：

omm=# show data_directory;
     data_directory      
-------------------------
 /var/lib/opengauss/data
(1 row)

系统层面版本信息：

omm=# select version();
                                                                        version                                                                        
-------------------------------------------------------------------------------------------------------------------------------------------------------
 (openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr   on aarch64-unknown-linux-gnu, compiled by g++ (GCC) 7.3.0, 64-bit
(1 row)