I just run a copy command for two large directories with a small number of huge files and I see my cp process is consuming around half a core in top:
51116 root 20 0 110m 876 688 D 43.9 0.0 3:23.83 cp -i -r 165 178 temp
Why does the cp process consume any cpu? I would imagine it spends most of it's time waiting on disk...
Thx, Boaz
I have a client software which calls and apache httpd server installed on the same machine. Before calling the apache logs a log entry:
2011-11-23 13:27:43,777 | 8323|1381677376 | root | DEBUG | Calling http://mydomain.com/api/project/325/postings/add_and_remove_labels
As you can see the call is made on 13:27:43 local time. The domain mydomain.com resolve the external IP of the same machine.
However , when I look at the access.log file, I say log entry whose time stamp[1] is 5 seconds later:
[23/Nov/2011:13:27:48 +0100] "GET /api/project/325/postings/add_and_remove_labels
This is a mod_wsgi base server running in daemon mode but I'm not sure if it is relevant (the time stamp should be the start if the request on the level of apache).
How can I best proceed to find out the source of these 5 seconds?
Cheers, Boaz
Clarification: [1] - The time stamp is when the request started. It is true the entry is written to the log when the request ends, but the time is of the request start.
I'm running a web services site on Apache HTTPd and every once in while I get an error indicating the incoming URL is too long (HTTPError: HTTP Error 414: Request-URI Too Large).
My site is servicing programs rather than browser so I'm not worried about the 2K browser limit.
Is there any way to get increase the acceptable URI length?
We're developing a web-app running under tomcat which relies on Java User preferences to store all kind of settings. That works great, but we've run into problem where we needed to set up another staging web-app which allows you to test settings before settings them live.
The core of the problem lies in the fact that Java User preferences are the same for all web-app due to the fact that all of them run under the tomcat user (configurable). For legacy reasons I can not at the moment change my preferences structure, so I'm hoping for a solution on the the tomcat configuration side.
Is it possible to designate a different user credentials for a specific web-app in tomcat?
Thanks, Boaz
I guess everyone knows the useful Linux cmd line utilities head and tail. head allows you to print the first X lines of a file, tail does the same but prints the end of the file. What is a good command to print the middle of a file? something like middle --start 10000000 --count 20 (print the 10’000’000th till th 10’000’010th lines).
I'm looking for something that will deal with large files efficiently. I tried tail -n 10000000 | head 10 and it's horrifically slow.
In the beginning of a crontab file you could use the MAILTO instruction to indicate you want the output to be sent as an e-mail to an e-mail address. I would like to send the output to multiple addresses. Is it possible (and how) to specify multiple addresses?
I have heavy application running on a CentOS server and I'm seeing a strange memory behavior. Here is a snapshot of a munin graph:
As you can see the amount of committed memory increases gradually causing the swap file to be use. What strikes me odd is that the amount of inactive memory keeps growing as well. It is my understanding that the inactive memory is actually memory freed up but not yet clean by the OS and put back in the free memory pool. It seems that running out of memory is acutally caused by this lack of clean up, but I may be wrong.
Can you give some tips to find the cause of the problem and/or cause CentOS to reclaim the inactive memory?
Thanks.
Some extra info:
1) I have a tmpfs mounted on /tmp and the number of files stored there grows (but it is double the amount of the inactive memory).
2) cat /proc/meminfo (at a later stage than the image) gives:
MemTotal: 14371428 kB
MemFree: 1207108 kB
Buffers: 35440 kB
Cached: 4276628 kB
SwapCached: 785316 kB
Active: 9038924 kB
Inactive: 3902876 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 14371428 kB
LowFree: 1207108 kB
SwapTotal: 10223608 kB
SwapFree: 6438320 kB
Dirty: 627792 kB
Writeback: 0 kB
AnonPages: 7844560 kB
Mapped: 49304 kB
Slab: 146676 kB
PageTables: 27480 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
CommitLimit: 17409320 kB
Committed_AS: 16471488 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 275852 kB
VmallocChunk: 34359462007 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
Hugepagesize: 2048 kB
3) The application is a combination of MySQL, Heritrix (http://crawler.archive.org/ ) and a Tomcat based Java servlet to manage things.
CentOS 5.4 comes with python 2.4 standard. Yum doesn't seem to know python 2.6. What is the best way to install python 2.6, so it will be available for scripts and Apache HTTPd without breaking anything else?