savannah: slow starting of mc

[nijman]

Original: ​http://savannah.gnu.org/bugs/?24038

Submitted by:	Ies Nijman <nijman>	Submitted on:	Mon 11 Aug 2008 03:21:54 PM UTC
Category:	Core	Severity:	3 - Normal
Status:	None	Privacy:	Public
Assigned to:	None	Open/Closed:	Open
Release:	4.6.2-pre1	Operating System:	Other

Original submission:

On openSuse 11 starting mc takes a very long time: about 30s. IpV6 
is disabled but VMware player is installed and so virtual network 
devices are present.

nslookup and netstat work immidiately so it isn't the gethostbyname 
issue.

A solution would be greatly appreciated.

Comment 1 by Oswald Buddenhagen <ossi> at Tue 12 Aug 2008 10:07:17 AM UTC:

you should attach the strace of such a startup.

Comment 2 by Ies Nijman <nijman> at Tue 12 Aug 2008 11:26:57 AM UTC:

Strace output added. Funny thing is that with strace, MC starts up 
rightaway...

(file #16277)

Comment 3 by Ies Nijman <nijman> at Tue 12 Aug 2008 12:43:53 PM UTC:

Previous results were from MC 4.6.1 (fast starting).

Next slow results from MC 4.6.2 and a strace file.

Comment 4 by Ies Nijman <nijman> at Tue 12 Aug 2008 02:28:09 PM UTC:

New strace file attached, now with timestamps.

It seems to timeout several times on
"RESOLVE-HOSTNAME-IPV4"

Strange because if I do nslookup with this host name it returns 
immediately..

(file #16281)

Comment 5 by Irakli <ika256> at Wed 03 Sep 2008 07:29:31 AM UTC:

I had this problem too
Solution is:
add "options no_tld_query" in resolv.conf

Comment 6 by Sorin Sbarnea <sorin> at Tue 07 Oct 2008 10:54:29 AM UTC:

I can confirm the same issue on multiple platform: OS X, Fedora and Ubuntu.

It's a real pain and this should be solved inside mc - mc is used as
a configuration tools and it's supposed to work even on systems 
where configuration is not "well done".

BTW. The solution with "options no_tld_query" in resolv.conf does 
not solves the problem in my case.

I don't remember exactly but I think it's somewhat related to 
/etc/hosts

Comment 7 by Sorin Sbarnea <sorin> at Thu 18 Dec 2008 10:48:06 AM UTC:

I can (re)confirm this problem on RHEL also.

The DNS is well configured. There is no delay running "netstat -a"

I wasn't able to locate any other program with simmilar behaviour on
 these machines.

Possible hint: some partitions are mounted using NIS.

If you are searching on google after "midnight commander slow start"
 you'll see that a lot of people are encountering this issue.

Comment 8 by Sorin Sbarnea <sorin> at Thu 18 Dec 2008 10:58:47 AM UTC:

I would like to add that I have the same problem with version 
4.6.1-pre1a and that "options no_tld_query" in resolv.conf does not 
work (tested even after system restart)

Comment 9 by Sorin Sbarnea <sorin> at Thu 18 Dec 2008 11:17:09 AM UTC:

If this helps: I have some NFS mounted drives but none of them if in
 one of the mc panes.

[slavazanko]

added by nijman

[slavazanko]

added by nijman

[ramas]

I can add that I am running this problem while on SSH from Putty (windows PC).

Running strace I saw that the startup pauses while trying to connect to port 6000 of my windows machine.

As a workaround I unset the DISPLAY shell variable and now mc starts fast as expected.

[slavazanko]

thanks for tip!

[ossi]

suppressing the problem should be as simple as checking whether WINDOWID is set in addition to DISPLAY before trying XOpenDisplay(). this ensures that mc is running directly inside xterm (or pretty much any other x terminal emulator) and consequently whether making the X connection seems to make sense at all (it's used for keyboard modifier tracking, to work around tty layer deficiencies). on the downside, it would also break modifier tracking for remote shells inside xterm which *do* have configured DISPLAY correctly (fixable with ssh (SendEnv? WINDOWID in ssh_config, AcceptEnv? WINDOWID in sshd_config), but needs root to fix. telnet also has an environment sending option. 'sux -' would be a problem, i think).

the alternative is setting an alarm() over the XOpenDisplay() (5 seconds ought to be enough) and printing "Connection to X server timed out. Please fix or clear $DISPLAY in the future."

[angel_il]

branch: ​86_disable_x11_flag

[IceMan]

Available binary packages with fixes applied (nightly build 4:4.8.0~git20111028-2) For Debian\Ubuntu see ​https://www.midnight-commander.org/wiki/Binaries.

[slavazanko]

New option should be described in MAN page.

[angel_il]

please review

[angel_il]

Fixed: 847b1093e7fabb2e8b8512df48615d8dc0b3c9f2

[angel_il]

cherry-picked into 4.8.1-stable 3e15b5af6450a2c93e3caf289fad3e8cf11ce89d