管理ONS(Oracle Notification Service)

时间：2022-03-15 02:13

Onsctl

Onsctl这个命令是用来管理ONS(Oracle Notification Service)是OracleClustser实现FAN Event Push模型的基础。

Oracle Notification Service (ONS)--A publish and subscribe service for communicating Fast Application Notification (FAN) events.

在RAC环境下，需要使用$CRS_HOME下的ONS，而不是$ORACLE_HOME下的ONS，这点需要注意。配置文件位于$CRS_HOME/opmn/conf/ons.config。

[oracle@felix2 conf]$ pwd

/u01/oracle/10.2.0/crs_1/opmn/conf

[oracle@felix2 conf]$ cat ons.config

localport=6113

remoteport=6200

loglevel=3

useocr=on

[oracle@felix2 conf]$ netstat -ano | grep 6200

tcp 0 0 0.0.0.0:6200 0.0.0.0:* LISTEN off (0.00/0/0)

tcp 0 0 192.168.10.102:8471 192.168.10.101:6200 ESTABLISHED off (0.00/0/0)

[oracle@felix2 conf]$ netstat -ano | grep 6113

tcp 0 0 127.0.0.1:6113 0.0.0.0:* LISTEN off (0.00/0/0)

tcp 0 0 127.0.0.1:42331 127.0.0.1:6113 ESTABLISHED keepalive (2251.34/0/0)

tcp 0 0 127.0.0.1:42328 127.0.0.1:6113 ESTABLISHED keepalive (2185.99/0/0)

tcp 0 0 127.0.0.1:6113 127.0.0.1:42331 ESTABLISHED off (0.00/0/0)

tcp 0 0 127.0.0.1:6113 127.0.0.1:42328 ESTABLISHED off (0.00/0/0)

unix 3 [ ] STREAM CONNECTED 6113

[oracle@felix2 conf]$

配置ONS:

添加ONS:

[oracle@felix2 conf]$ racgons add_configfelix11:6200 felix22:6200

删除ONS:

[oracle@felix2 conf]$ racgons remove_configfelix11:6200 felix22:6200

[oracle@felix2 conf]$

Onsctl命令：

使用onsctl命令可以启动、停止、调试ONS，并重新载入配置文件，其命令格式如下：

注意：

ONS进程运行，并不一定代表ONS正常工作，需要使用ping命令来确认。

[oracle@felix2 conf]$ onsctl

usage: /u01/oracle/10.2.0/db_1/bin/onsctlstart|stop|ping|reconfig|debug

start - Start opmn only.

stop - Stop ons daemon

ping - Test to see ifons daemon is running

debug - Display debuginformation for the ons daemon

reconfig - Reload the onsconfiguration

help - Print a shortsyntax description (this).

detailed - Print a verbosesyntax description.

（1）在os级别查看进程

[oracle@felix2 conf]$ ps -ef | grep ons

root 2530 1 0 20:19 ? 00:00:00 sendmail: acceptingconnections

oracle 5223 1 0 20:22 ? 00:00:00/u01/oracle/10.2.0/crs_1/opmn/bin/ons -d

oracle 5224 5223 0 20:22 ? 00:00:00 /u01/oracle/10.2.0/crs_1/opmn/bin/ons-d

oracle 10833 29589 0 21:59 pts/2 00:00:00 grep ons

[oracle@felix2 conf]$

（2）确认ONS服务的状态

[oracle@felix2 conf]$ onsctl ping

Number of configuration nodes retrieved: 2

0: {node = felix1, port = 6200}

Adding remote host felix1:6200

1: {node = felix2, port = 6200}

Remote port for local node in local config doesnot match that from OCR.

ons is not running ...

[oracle@felix2 conf]$

从输出的信息课件，ONS服务是停止的。

（3）启动ONS服务

[oracle@felix2 conf]$ onsctl start

Number of configuration nodes retrieved: 2

0: {node = felix1, port = 6200}

Adding remote host felix1:6200

1: {node = felix2, port = 6200}

……

Comparison of Fast Connection Failover and TAF

Fast Connection Failover differs from Transparent Application Failover (TAF) in the following ways:

Application-level connection retries

Fast Connection Failover supports application-level connection retries. This gives the application control of responding to connection failovers. The application can choose whether to retry the connection or to rethrow the exception. TAF supports connection retries only at the OCI/Net layer.
Integration with the implicit connection cache

Fast Connection Failover is well-integrated with the implicit connection cache, which allows the Connection Cache Manager to manage the cache for high availability. For example, failed connections are automatically invalidated in the cache. TAF works at the network level on a per-connection basis, which means that the connection cache cannot be notified of failures.
Event-based

Fast Connection Failover is based on the Oracle RAC event mechanism. This means that Fast Connection Failover is efficient and detects failures quickly for both active and inactive connections.
Load-balancing support

Fast Connection Failover supports UP event load balancing of connections and run-time work request distribution across active Oracle RAC instances.