Finding problems in a program and trying to solve these.
Questions tagged [debugging]
202 questions
4
votes
3 answers
Monitoring HTTP 5xx errors in an Azure App Service
The Azure App service UI used to have an ability to inspect 5xx errors directly. Since we starting using Azure, the UI has been changing almost constantly though, and this ability seems to have disappeared.
We are seeing some 5xx errors, and without…
Scuba Steve
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4
votes
1 answer
What might be causing repeated mmap/munmap in strace results?
I have a (node.js) application which is occasionally causing 100% CPU usage. I've attached to the process with strace when it's been in this state - but I don't know what to make if the strace output. The results repeat between these two patterns…
UpTheCreek
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4
votes
1 answer
Verifying RADIUS server is sending the correct certificates?
How can I see the TLS (SSL) certificates that my RADIUS server is using, to make sure it is sending the correct certificate and chain?
I am implementing 802.1x authentication with a RADIUS server, but I have certificate acceptance problems on some…
Jan Fabry
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4
votes
1 answer
Describing `strace` command output
I have php process which could not finish for more then 2 days.
root 26511 0.0 1.6 407788 27684 ? Ss Jul09 0:08 /usr/bin/php action.php
This is the output from the strace command:
poll([{fd=7,…
ibedelovski
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4
votes
1 answer
Lighttpd won't start when fastcgi.debug directive is used
I'm running lighttpd/1.4.28 (ssl) on Ubuntu 12.04 LTS. Everything's working, and I'm trying to do some performance tuning. I'd like to enable debug mode for the fastcgi module, however when I add the directive fastcgi.debug to my conf file,…
Alan
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4
votes
3 answers
Getting debug output from a debian initramfs
I'm attempting to configure a server for a debian lenny on software raid0 and a LVM root filesystem via the serial console and the hosting company's recovery console (basically an ubuntu liveCD).
After configuring the raid0, establishing LVM,…
bdonlan
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4
votes
1 answer
centos 6 debuginfo repository does not have httpd debug version available
I am trying to get the debug version of httpd so I can use it in conjunction with gdb. I am having a hard time getting them, and they don't seem to be in the standard epel-debuginfo repository. What should I do?
> [root@buildbox-rhel6 ~]#…
Zippy Zeppoli
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4
votes
1 answer
Crash dump analysis
I hope this isn't a stupid question, and if it is, then I want to at least get it over with so I don't feel so dumb in the future.
Here we are, loading up a Windows crash dump with Windbg. Here are the first few lines of the debugger output:
0: kd>…
Ryan Ries
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4
votes
1 answer
Why can't openSSL verify google's certificate?
When I run the command openssl -connect www.google.com:443 from a Debian VM, I get the following within the output:
Verify return code: 20 (unable to get local issuer certificate)
What's going on here? I've never had a cert problem with Google,…
jldugger
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4
votes
2 answers
Configuration parameter in xdebug for allowing multiple hosts on remote machine
I am working on one web application. The project located on my linux box i.e. server. We are remotely accessing this machine from windows.
I am using xdebug for debugging alongwith Eclipse PDT. xdebug is installed on my server. Below configuration…
user52534
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3
votes
1 answer
How to debug linux startup hang
My ubuntu system hangs on the startup. It hangs on [OK] items like usual on boot. Interestingly, I am able to ssh onto this machine, but the boot never finishes and login screen doesn't appear. What should I do to debug the problem?
Konstantin Solomatov
- 137
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3
votes
2 answers
How do I Identify an anonymous process that's changing a system setting?
I see an anonymous process changing the time of my systemtime to UTC every 80 sec. Using the journalctl -f command I only see a message that says
'systemd[1]: time has been changed' but it doesn't identify which process is doing that.
I know that…
user1851006
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3
votes
1 answer
Debug DNS: What to do if host name resolution does not work as expected?
The current search results for "debug dns" don't reveal a guide-line what to do, if you (as user/client) think there is something wrong with the host name resolution.
What steps can I do to narrow down the problem?
My particular case:
The tool host…
guettli
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3
votes
1 answer
How to debug/log 502 Bad Gateway from reverse proxy?
We're running a web service and hitting 502 Bad Gateway randomly. The 502 is reported by reverse proxy (Apache 2.4.x) while talking to backend server (Apache 2.4.x). The problem randomly re-appears around once per 100,000 served requests so it's…
Mikko Rantalainen
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3
votes
0 answers
Obtaining a Crash Dump from a dying IIS ASP.NET Worker Process
(Not sure if this is an IIS problem or not, so if this is better suited for SO I'll happily move it...)
We have an IIS-hosted application that is sporadically dying, and the event logs claim that the application pool is reporting itself as unhealthy…
KutuluMike
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