cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Reid Pinchback <>
Subject Re: Cassandra Recommended System Settings
Date Mon, 21 Oct 2019 14:29:46 GMT
I don't know which distro and version you are using, but watch out for surprises in what vm.swappiness=0
means.  In older kernels it means "only use swap when desperate".  I believe that newer kernels
changed to have 1 mean that, and 0 means to always use the oomkiller.  Neither situation is
strictly good or bad, what matters is what you intend the system behavior to be in comparison
with whatever monitoring/alerting you have put in place.


´╗┐On 10/18/19, 9:04 PM, "Sergio Bilello" <> wrote:

     Message from External Sender
    Hello everyone!
    Do you have any setting that you would change or tweak from the below list?
    sudo cat /proc/4379/limits
    Limit                     Soft Limit           Hard Limit           Units
    Max cpu time              unlimited            unlimited            seconds
    Max file size             unlimited            unlimited            bytes
    Max data size             unlimited            unlimited            bytes
    Max stack size            unlimited            unlimited            bytes
    Max core file size        unlimited            unlimited            bytes
    Max resident set          unlimited            unlimited            bytes
    Max processes             32768                32768                processes
    Max open files            1048576              1048576              files
    Max locked memory         unlimited            unlimited            bytes
    Max address space         unlimited            unlimited            bytes
    Max file locks            unlimited            unlimited            locks
    Max pending signals       unlimited            unlimited            signals
    Max msgqueue size         unlimited            unlimited            bytes
    Max nice priority         0                    0
    Max realtime priority     0                    0
    Max realtime timeout      unlimited            unlimited            us
    These are the sysctl settings
    default['cassandra']['sysctl'] = {
    	'net.ipv4.tcp_keepalive_time' => 60, 
    	'net.ipv4.tcp_keepalive_probes' => 3, 
    	'net.ipv4.tcp_keepalive_intvl' => 10,
    	'net.core.rmem_max' => 16777216,
    	'net.core.wmem_max' => 16777216,
    	'net.core.rmem_default' => 16777216,
    	'net.core.wmem_default' => 16777216,
    	'net.core.optmem_max' => 40960,
    	'net.ipv4.tcp_rmem' => '4096 87380 16777216',
    	'net.ipv4.tcp_wmem' => '4096 65536 16777216',
    	'net.ipv4.ip_local_port_range' => '10000 65535',
    	'net.ipv4.tcp_window_scaling' => 1,
           'net.core.netdev_max_backlog' => 2500,
           'net.core.somaxconn' => 65000,
    	'vm.max_map_count' => 1048575,
    	'vm.swappiness' => 0
    Am I missing something else?
    Do you have any experience to configure CENTOS 7



    We are using AWS i3.xlarge instances
    To unsubscribe, e-mail:
    For additional commands, e-mail:

View raw message