lightdb22.2-新增集群启停脚本

lightdb22.2 版本新增了集群启停脚本，脚本名为lightdb_service.py。使用python2.7开发。使用该脚本会对涉及的lightdb,ltcluster,keepalive 进行相应操作。

由于需要依赖installer安装后生成的json文件来获取集群信息，目前此脚本只能用于通过installer安装的数据库集群，且需要使用root用户执行（因为涉及keepalive的启停，需要root权限）。

usage: lightdb_service.py [-h] [-F OP_INSTALL_INFO]
                          [-c {start,stop,restart,status}] [-C] [-D] [-P] [-S]
                          [--dry-run] [-f] [-B ] [-v] [-q]
                          [-l ]

optional arguments:
  -h, --help            show this help message and exit
  -F OP_INSTALL_INFO, --filename OP_INSTALL_INFO
                        specifies the path to a json file containing
                        installation information
  -c {start,stop,restart,status}, --command {start,stop,restart,status}
                        start/stop/restart/status lightdb service
  -C, --cn_only         only start/stop coordinator node
  -D, --dn_only         only start/stop data node
  -P, --primary_only    only start/stop primary node for primary restart
  -S, --standby_only    only start/stop standby node for standby restart
  --dry-run             show what would happen for action, but don't execute
                        it
  -f, --force           force stop of cluster even if some nodes are in
                        incorrect state, skip incorrect nodes
  -B , --parallel 
                        number of segment hosts to run in parallel. Default is
                        1
  -v, --verbose         debug print
  -q, --quiet           suppress status messages for stdout logging
  -l , --log_dir 
                        Logfile directory, default is /tmp/ltAdminLogs

lightdb_service.py -c start/stop/restart

lightdb_service.py -c start/stop/restart --cn_only 

lightdb_service.py -c start/stop/restart --dn_only 

lightdb_service.py -c start/stop/restart --primary_only 

lightdb_service.py -c start/stop/restart --standby_only 

lightdb_service.py -c start/stop/restart --parallel 4