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I am using PostgreSQL 9.5 with a Java 8 Application on Windows OS (System: i5 2nd Generation). I noticed that when my application is in execution, there are several PostgreSQL processes / sub-processes that are created/removed dynamically.
These PostgreSQL processes use almost all of the CPU (>95%), due to which problem arises with other applications installed at my system.
I recently came to know about CPU affinity. For the time being, I am executing PowerShell script (outside of my Java application) which checks periodically and sets the desired value of cpu affinity for all PostgreSQL processes in execution.
I am looking for a way where I don't need to execute an external script(s) and/or there is one-time configuration required.
Is there a configuration supported by PostgreSQL 9.5 through which we can set max CPU cores to be used by PostgreSQL processes?
I looked for the solution, but could not find any.
There is no way to set this in the PostgreSQL configuration.
But you can start your PostgreSQL server from cmd.exe with:
start /affinity 3 C:\path\to\postgresql.exe C:\path\to\data\directory
That would allow PostgreSQL to run only on the twp “first” cores.
The cores are numbered 1, 2, 4, 8, 16 and so on, and you use the sum of the cores where you want PostgreSQL to run as argument to /affinity. For example, if you only want it to run on the third and fourth core, you would use /affinity 12.
This should work, since the Microsoft documentation says:
Process affinity is inherited by any child process or newly instantiated local process.
I'm running a rundeck server to delegate a simple script to 5.8k other linux servers.
The very simple script is bellow
!/bin/bash
A=$(hostname)
echo $A
When i run the same job with a smaller number of targets (4089 nodes)
the comands work fine
I tried looking at my service.log page and its not incrementing anything
Any ideas on how to be able to run on all the 5.8k nodes? And where should i look for errors?
Rundeck does not have limits to nodes, certainly depends on how many executions you want to run, how much ram, how many processors and disk space.
Maybe you need to increase the Java heap size:
https://rundeck.org/docs/administration/maintenance/tuning-rundeck.html#java-heap-size
And how to adapt this to your SSH plugin:
https://rundeck.org/docs/administration/maintenance/tuning-rundeck.html#built-in-ssh-plugins
i have a Centos 5 server which hosted asterisk 13.
server works fine last week but now top command always show me a process with large amount of CPU usage. when i kill the process a few second later another command with large CPU usage started. many times processes command is ".syslog" but have other command like "qjennjifes", "vnvebynufu" and another unknown commands like that.
1) Check you have firewall and fail2ban recomended settings
2) Check you have no DoS/DDoS by "sip show channels"
3) Check your system not hacked/no broken soft on your host.
I have to run a series of simulations and save the results. Since by default Matlab only uses one core, I wonder if it is possible to open multiple worker tasks and assign different simulation runs to them?
You could run each simulation in a separate MATLAB instance and let the OS handle the process to core assignment.
One master MATLAB could synchronize each child instances checking for example if simulation results file are existing.
I aso have the same problem but I did not manage to really understand how to make it in MatLab. The documentation in matlab is too advanced to get to know how to make it.
Since I am working with Ubuntu I find a way to do the work calling the unix command from MatLab and using the parallel GNU command
So I mange to run my simulation in parallel with 4 cores.
unix('parallel --progress -j4 flow > /dev/null :::: Pool.txt','-echo')
you can find more info in the link
Shell, run four processes parallel
Details of the syntaxis can be found at https://www.gnu.org/software/parallel/
but breifly I can tell you
--progress shows a status of the progress
-j4 tells the amount or jobs in parallel you want to have
flow is the name of my simulator
/dev/null was just to avoid the screen run output of the simulator to show up
Pool.txt is a file I made with the required simulator input that is basically the path and the main simulator file.
echo I do not remember now what was it for :D
I am very new to LSF. I have 4 nodes with with 2 sockets per node. Each node is having 8 cores. I have developed hybrid MPI+OpenMP code. I am submitting the job like the following which asks each core to perform one MPI task. So I loose the power of OpenMP.
##BSUB -n 64
I wish to submit the job so that each socket runs one MPI task rather than each core so that the cores inside the socket can be used for OpenMP. How can I build up job submit scripts to optimize the power of the Hybridization in my code.
First of all, the BSUB sentinels have to be preceded by a single # sign, otherwise they are skipped over as a regular comments.
The correct way to start a hybrid job with older LSF versions is to pass the span resource request and request nodes exclusively. To start a job with 8 MPI processes and 8 OpenMP threads each, you should use the following:
#BSUB -n 8
#BSUB -x
#BSUB -R "span[ptile=2]"
The parameters are as following:
-n 8 - requests 8 slots for MPI processes
-x - requests nodes exclusively
-R "span[ptile=2]" - instructs LSF to span the job over two slots per node
You should request nodes exclusively, otherwise LSF will schedule other jobs to the same nodes since only two slots per node will be used.
Then you have to set the OMP_NUM_THREADS environment variable to 4 (the number of cores per socket), tell the MPI library to pass the variable to the MPI processes, and make the library limit each MPI process to its own CPU socket. This is unfortunately very implementation-specific, e.g.:
Open MPI 1.6.x or older:
export OMP_NUM_THREADS=4
mpiexec -x OMP_NUM_THREADS --bind-to-socket --bysocket ./program.exe
Open MPI 1.7.x or newer:
export OMP_NUM_THREADS=4
mpiexec -x OMP_NUM_THREADS --bind-to socket --map-by socket ./program.exe
Intel MPI (not sure about this one as I don't use IMPI very often):
mpiexec -genv OMP_NUM_THREADS 4 -genv I_MPI_PIN 1 \
-genv I_MPI_PIN_DOMAIN socket -genv I_MPI_PIN_ORDER scatter \
./program.exe