Is there any way to bind a process / (or a thread) to a particular core in FreeBSD//Linux
I googled could not find an answer. But people must be doing it and I am surprised that the answer is not easily available
Thanks for any inputs
From the command line you can use taskset. From within your code you can use sched_setaffinity.
$ man taskset
$ man sched_setaffinity
For FreeBSD you can also consider its following counterparties
$ man cpuset(1)
$ man cpuset(2)
There's a somehow related topic on server fault to check
Related
On centos
sudo lokkit -s http
opens up the service.
I have been reading the documentation and I was googling for a while, but I cannot figure out how to turn off the service (undo the result of the above). Surely the writers of lokkit must have thought that that would be needed, so it must be there somewhere. Thanks!
I am installing the MapR and I stucked at starting warden after start zookeeper on a single node.
# service mapr-warden start
Error: warden can not be started. See /opt/mapr/logs/warden.log for details
On this file there is no detail. Does anybody have a hint? Thanks =)
If you aren't getting anything in warden.log, then it's likely that the warden JVM is never even being started by the mapr-warden init script.
In some MapR versions, the mapr-warden init script will log some details into /opt/mapr/logs/wardeninit.log. You can try checking there.
However, I will also caution that currently the logging done by the init script is sparse and not necessarily user friendly to read. If you can't discern the cause from the contents of the wardeninit.log you can post them here and maybe I can help.
Another thing you can do is edit /etc/init.d/mapr-warden and add "set -x" towards the top of the file, right before the "BASEMAPR=" line, then try starting warden again and you'll get a bunch of shell debugging output on your screen. If you copy and paste that output here that should be enough to tell the root cause of the problem.
One more thing to mention, you may be better off using the http://answers.mapr.com forum as that is MapR specific and I think there may be more users there that could help.
Was configure.sh (/opt/mapr/server/configure.sh -C nodeA -Z nodeA)run on the node? Did zookeeper come up successfully?
service mapr-zookeeper status
Even when using MapR in a single node configure.sh is still required. In fact, without configure.sh warden, zookeeper, cldb and other MapR components will lack their configuration and in many cases will fail to start.
You must run configure.sh after installing the software packages (deb or rpm).
Does MongoDB create a file I can poll for in order to determine when prealloc is done? Right now I have a script to run rs.init(..config..), but I need to wait with triggering it until mongod is up and running.
Since tail -f | grep .. | xarg.. the log file is a bit of a flaky hack, I wondered if there is any other way to determine that mongod is done with prealloc?
We have the same problem for testing replica sets with the PHP driver. Here we use the mongo shell's ReplSetTest() functionality to get around this. You can see here how that works:
https://github.com/mongodb/mongo-php-driver/blob/master/tests/utils/myconfig.js#L9
However, I am not sure how well this works for non-test environments as the amount of options you can give are rather limited (such as, you can't set a data dir properly as things are hardcoded). All the functions and code for this is all in JavaScript at https://github.com/mongodb/mongo/blob/master/src/mongo/shell/replsettest.js — this should give you an overview how it works and allows you to rewrite it in your preferred language.
try to use inotify (i am not sure exactly), for example, if it is necessary to determine that the file is closed after writing:
[maverick#mutabor ~]$ pyinotify -e IN_CLOSE_WRITE /tmp/testfile
Does anyone know a way to list mounted TrueCrypt volumes to stdout via the command line?
The page below suggests the --list option would do it in the *nix version, but I can't find any way to do this with Windows.
http://www.irongeek.com/i.php?page=backtrack-3-man/truecrypt
I faced with same question and found solution, use forward slash symbol. Example here
In addition use "/help" key.
Hope this helps you.
I have a shell script which archives log files based on the whether the process is running or not. If the log file is not used by the process then I archive it. Until now, I'm using lsof to get the log file being used but in future, I have decided to use perl to do this function.
Is there a perl module similar to what lsof in linux can perform ?
There is a perl module, which wraps around lsof. See Unix::Lsof.
As I see it, the big problem with not using lsof is that one would need to work in a way that is independent of the operating system. Using lsof allows the perl programmer to work with a consistent application allowing for operating system independence.
To have a perl module developer to write lsof would, in effect, be writing lsof as a library and then link that into perl - which is much more work than just using the existing binary.
One could also use the fuser command, which shows the process IDs with the file handle. There is also a module which seeks to implement the same functionality. Note from the perldoc:
The way that this works is highly unlikely to work on any other OS
other than Linux and even then it may not work on other than 2.2.*
kernels.
One might try walking /proc/*/fd and looking at the file descriptors in there to see if any are pointing to the file in question. If it is known what the process ID of a running process that would be opening the log file, it would be just as easy to look at that process. Note, that this is how the fuser module works.
That said, it should be asked "why do you want to move away from lsof"?