Finding problems in a program and trying to solve these.
Questions tagged [debugging]
202 questions
9
votes
4 answers
How to debug "HTTP request sent, awaiting response"?
I have a Linux server on an ADSL connection, and I just noticed that sometimes I get
Connecting to example.com|xxx.xxx.xxx.122|:80... connected.
HTTP request sent, awaiting response...
when I use wget or e.g. a browser like firefox.
In the case of…
Sandra
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9
votes
3 answers
Performing root-cause analysis
I want to learn more about how to perform root-cause analysis. More times than not, our department tells the user to try rebooting (thier Windows XP system), which actually "fixes" a good number of problems. When I am in a hurry (and sometimes…
jftuga
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8
votes
2 answers
Online mod_rewrite testing tool
mod_rewrite statements can be hard to write and debug, therefore I need a lightweight online tool that enables me to test my RewriteCond, RewriteRule statements on the fly.
Any such tool?
Graviton
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7
votes
3 answers
Why is MemAvailable a lot less than MemFree+Buffers+Cached?
I'm running a Linux workstation without swap and I have installed earlyoom daemon to automatically kill some processes if I'm running out of RAM. The earlyoom works by monitoring kernel MemAvailable value and if the available memory gets low enough,…
Mikko Rantalainen
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7
votes
1 answer
How to debug CGI over fcgiwrap/nginx
I serve executable scripts (mainly in C) through fcgiwrap connected with nginx. Since the scripts are complied, I can get the coding errors during compilation, but sometimes I receive CGI errors simply stating
An error occurred while reading CGI…
Googlebot
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7
votes
1 answer
SQL Server Debugging: "Unable to Step. Invalid operation"
I'm debugging a call to a Stored Procedure in SSMS (2012). Frequently, and various random points in the code, a dialog pops up:
Microsoft SQL Server Management Studio:
Unable to Step. Invalid Operation.
Once I dismiss the dialog, it appears that…
CJM
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7
votes
1 answer
How to configure PHPStorm to debug on IIS
I installed PHP 5 on IIS on a Windows 7 64 bit machine using the Web Platform Installer. I am using PHPStorm as my PHP IDE but cant find any documentation on how to get debugging to work. PHPStorm launches my PHP web application but breakpoints do…
rams
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6
votes
4 answers
How to pinpoint which process/activity/software/protocol is slowing down LAN on a single computer
From this question about debugging our business LAN I've been able to pinpoint a single computer which slows down our network.
When the computer is turned on and connected to the network, roughly 5% of all site interactions (that is, clicks on links…
Félix Gagnon-Grenier
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6
votes
3 answers
All connections from this network get stuck in SYN_RECV state, connections from my home or phone properly get ESTABLISHED
My server (a linode VPS) suddenly started to timeout on every request yesterday.
I'm pretty inexperienced in networking and would love to learn a process for debugging these connectivity issues.
What confuses me is that yesterday, some people (my…
Yuji Tomita
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6
votes
3 answers
How do I identify slow queries in sql server?
I've found long, complicated instructions like this when googling for the answer to this question, an brief reference links such as in this post.
I'm looking for a succinct a procedure as possible to generate a list of SQL queries with execution…
adambox
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5
votes
1 answer
Ubuntu Server with systemd - how to get a backtrace or coredump?
I'm using Ubuntu 18.04 Server with systemd. Recently a program my department has developed crashed twice within a day with the following error:
Jun 07 06:33:07 xxx systemd[1]: xxx.service: Main process exited, code=killed, status=11/SEGV
Jun 07…
cdahms
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5
votes
1 answer
How to debug Node + Socket.io CPU Issues
We are running a Node Socket.io server with Express 3. The server is monitored using Forever. The service is running well, but the CPU grows throughout the day, until it reaches 90%+ and then suddenly drops back down to ~20%, as shown in the graphs…
SteveEdson
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5
votes
4 answers
How can I investigate sustained high CPU usage by Microsoft.Exchange.Rpc.ClientAccess.Service.exe?
One CAS server in our array has nearly 90% of its 4 CPUs used. The remaining CAS servers are at 30 percent.
How should I investigate what is causing this increase?
Below is a graph of:
Six (6) CAS servers serving 3,000 users in RPC/HTTPS…
makerofthings7
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5
votes
2 answers
Why would brk() in strace output be taking several seconds?
We've been noticing a significant slowdown of one of our applications when migrated to Ubuntu Hardy, amd64. It runs perfectly well on Debian Sarge i386.
Running an 'strace -r' against the (Apache 1.3) httpd process has shown the following troubling…
Mike Pountney
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5
votes
2 answers
nginx. How to log ssl errors without blowing up the server logs
I have a web site, that is visited by many different mobile devices and embedded devices.
Quite often I encounter the issue, that some devices cannot connect.
The reasons can be:
the device doesn't recognize an certain CA
the device is too old and…
gelonida
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