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Sergio avatar image
Sergio asked ·

CentosOS7 - Cassandra 3.11.4 Kernel/OS Recommended Settings on AWS i3.xlarge instances

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

for

JAVA HUGE PAGES

https://docs.datastax.com/en/dse/5.1/dse-admin/datastax_enterprise/config/configRecommendedSettings.html#CheckJavaHugepagessettings


OPTIMIZE SSD

https://docs.datastax.com/en/dse/5.1/dse-admin/datastax_enterprise/config/configRecommendedSettings.html#OptimizeSSDs


https://docs.datastax.com/en/dse/5.1/dse-admin/datastax_enterprise/config/configRecommendedSettings.html


We are using AWS i3.xlarge instances


Thanks,


Sergio

configuration3.11.4i3.xlargekernelsettings
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1 Answer

Lewisr650 avatar image
Lewisr650 answered ·

The most notable tuning configurations are:

1) turn off swap (these systems are intended to be dedicated)

2) Max_Heap of the JVM to allocate proper amount of memory for DSE/Cassandra to run in.

3) New_Heap alllocation sizing to minimize the impact of garbage collection.

Any settings that are modified should correlate to the performance interactions of the application. (Heave read vs. heavy write, etc.) Other dependancies are related to the type of workload.

DataStax provides a pre-flight checklist to validate settings of your OS here:

https://docs.datastax.com/en/dse/6.7/dse-dev/datastax_enterprise/tools/dsePreFlight.html

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