[Spacewalk-list] Keepalive for Database Connections?

[Stefan Lasche]

> 
> Hi Stefan,
> 
> you can create /etc/tnsname.ora with connect string you need.
> Then just change db_name in /etc/rhn/rhn.conf to the tnsname you've created
> (instead of default //host:port/name) and that's it :).
>

Thanks a lot Michael! That did the trick. The file is actually called /etc/tnsnames.ora and not /etc/tnsname.ora
Small difference, with big effects ;)
I wrote a small tutorial - just in case anyone else is interested:

How to implement Keepalive for Oracle Instant Client (for use in Spacewalk). Oracle Client will use the TCP Keepalive Feature of the Operating System (in my case Linux).

1)	create /etc/tnsnames.ora by closely following the example in the "ENABLE" Section of the Oracle Docs: http://docs.oracle.com/cd/B28359_01/network.111/b28317/tnsnames.htm#CHDCDGCE

2)	use Michael's magic and edit Spacewalk's /etc/rhn/rhn.conf. Change "db_name = //your_db_server_name/your_db " 
	into "db_name = net_service_name" (use the same net_service_name you used in your /etc/tnsnames.ora)

3)	check the kernel's current keepalive values:
		# sysctl -a | grep keepalive
		net.ipv4.tcp_keepalive_time = 7200	# send the first keepalive after 3600 seconds (2h)
		net.ipv4.tcp_keepalive_intvl = 75	# after the first keepalive, send keepalives every 75 seconds
		net.ipv4.tcp_keepalive_probes = 9	# kill connection after 9 failed keepalives

4)	Adjust the kernels Keepalive values to your needs:
		# sysctl –w net.ipv4.tcp_keepalive_time=1800
		# echo “net.ipv4.tcp_keepalive_time = 1800” >> /etc/sysctl.conf

5)	restart Spacewalk 
		# /usr/sbin/spacewalk-service stop && /usr/sbin/spacewalk-service start

6)	check if keepalive is now enabled for your database connections (use "netstat -tpno" and check the last two columns for the word "keepalive" and the corresponding timer values)
		# netstat -tnpo 
		tcp        0      0 192.168.1.1:54729         192.168.2.2:1521         ESTABLISHED 26988/java          keepalive (1530.03/0/0)
		tcp        0      0 192.168.1.1:54718         192.168.2.2:1521         ESTABLISHED 26944/httpd         keepalive (1522.62/0/0)

7)	enjoy your space walk ;)

__
regards,
Stefan