net.ora设置sqlnet.expire_time断开时oracle如何探测.txt

--//测试sqlnet.ora设置sqlnet.expire_time断开时oracle如何探测的,这个测试我以前做过,链接找不到了,重新测试加强记忆.

1.环境:
SYS@192.168.31.8:1521/hrp430> @ ver1

PORT_STRING                    VERSION        BANNER
------------------------------ -------------- --------------------------------------------------------------------------------
x86_64/Linux 2.4.xx            11.2.0.3.0     Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production

--//今天上午发现设置sqlnet.expire_time=1也不行.正好测试看看.
$ grep sqlnet.expire_time $ORACLE_HOME/network/admin/sqlnet.ora
sqlnet.expire_time=1

2.测试:
--//服务端执行:
# seq 100000 | xargs -IQ bash -c "netstat -tonp | grep 192.168.100.78:|ts.awk;sleep 0.999999" | tee aa.txt
--//注:我sleep 0.999999可能避免一些命令执行时的误差.看了以前测试我以前这里使用tcpdump来跟踪的.

--//客户端执行:
$ rlsql sys/XXXX@192.168.31.8:1521/hrp430 as sysdba
SQL*Plus: Release 11.2.0.4.0 Production on Fri Jan 15 10:10:18 2021
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

--//注登录后不要再执行任何命令,另外最好使用NTP保证客户端端与服务器时间同步,这样好诊断问题.
--//剩下就是等待问题出现.如果你想模拟有不想等2*sqlnet.expire_time时间,注我这里设置很短,许多用户无法模拟这个问题的.
--//可以拔掉客户端网线或者使用iptables阻塞连接(小心不要设置错误!!),并且服务端最好在tmux或者screen下操作,这样服务端的连接不会断开.

3.中间查看情况:
# seq 100000 | xargs -IQ bash -c "netstat -tonp | grep 192.168.100.78:|ts.awk;sleep 0.999999" | tee aa.txt
[2021-01-15 10:10:19] tcp        0      0 ::ffff:192.168.31.8:1521    ::ffff:192.168.100.78:7763  ESTABLISHED 27737/oraclehrp430  off (0.00/0/0)
[2021-01-15 10:10:20] tcp        0      0 ::ffff:192.168.31.8:1521    ::ffff:192.168.100.78:7763  ESTABLISHED 27737/oraclehrp430  off (0.00/0/0)
...
[2021-01-15 10:12:17] tcp        0      0 ::ffff:192.168.31.8:1521    ::ffff:192.168.100.78:7763  ESTABLISHED 27737/oraclehrp430  off (0.00/0/0)
[2021-01-15 10:12:18] tcp        0     10 ::ffff:192.168.31.8:1521    ::ffff:192.168.100.78:7763  ESTABLISHED 27737/oraclehrp430  on (0.12/0/0)
~~~~~~~~~~~~~~~~~~~~~
[2021-01-15 10:12:19] tcp        0     10 ::ffff:192.168.31.8:1521    ::ffff:192.168.100.78:7763  ESTABLISHED 27737/oraclehrp430  on (0.24/2/0)

--//注意看下划线内容,登录10:10:18,10:12:18断开正好2分钟.
--//后面的状态从off变成on.

4.分析:
--//出现on后大约等925秒(15分钟),连接就会断开.这个时候你可以出去聊天干别的事情.
# seq 100000 | xargs -IQ bash -c "netstat -tonp | grep 192.168.100.78:|ts.awk;sleep 0.999999" | tee aa.txt
[2021-01-15 10:27:45] tcp        0    160 ::ffff:192.168.31.8:1521    ::ffff:192.168.100.78:7763  ESTABLISHED 27737/oraclehrp430  on (5.03/15/0)
[2021-01-15 10:27:46] tcp        0    160 ::ffff:192.168.31.8:1521    ::ffff:192.168.100.78:7763  ESTABLISHED 27737/oraclehrp430  on (3.90/15/0)
[2021-01-15 10:27:47] tcp        0    160 ::ffff:192.168.31.8:1521    ::ffff:192.168.100.78:7763  ESTABLISHED 27737/oraclehrp430  on (2.77/15/0)
[2021-01-15 10:27:48] tcp        0    160 ::ffff:192.168.31.8:1521    ::ffff:192.168.100.78:7763  ESTABLISHED 27737/oraclehrp430  on (1.65/15/0)
[2021-01-15 10:27:49] tcp        0    160 ::ffff:192.168.31.8:1521    ::ffff:192.168.100.78:7763  ESTABLISHED 27737/oraclehrp430  on (0.52/15/0)