ONS（Oracle notification service）
ONS--A publish and subscribe service for communicating Fast Application Notification (FAN) events. 主要用于中间件和数据库的相连.
ps -ef |grep ons
crs_stat -t
Name Type Target State Host
------------------------------------------------------------
ora.orcl1.ons application ONLINE OFFLINE
crs_start ora.orcl1.ons
ONS log: $GRID_HOME/opmn/logs/ons.log.*
ONS config: $GRID_HOME/opmn/conf/ons.config
grep port $GRID_HOME/opmn/conf/ons.config
localport=6100 # line added by Agent
remoteport=6200 # line added by Agent
lsof | grep 6200 | grep LISTEN
netstat -an | grep 6200 | grep LISTEN
如果进程有守护进程，需要先kill 父进程
srvctl status nodeapps
crs_stat -ls
onsctl
usage: onsctl [verbose] []
The verbose option enables debug tracing and logging (for the server start).
Permitted / combinations are:
command options
------- ---------
start - Start ons
shutdown - Shutdown ons
reload - Trigger ons to reread its configuration file
debug [= ..] - Display ons server debug information
set [= ..] - Set ons log parameters
query [=] - Query ons log parameters
ping [] - Ping local ons
help - Print brief usage description (this)
usage [] - Print detailed usage description