Netdata: Difference between revisions
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Netdata is one of the [https://discourse.equality-tech.com/t/dashboards-in-qualitybox/107 QualityBox dashboards]. | Netdata is one of the [https://discourse.equality-tech.com/t/dashboards-in-qualitybox/107 QualityBox dashboards]. | ||
<!-- These services/entry points are disabled in production | |||
See [{{SERVER}}:20000/ this website Live] | See [{{SERVER}}:20000/ this website Live] | ||
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[{{SERVER}}:20000/netdata.conf Configuration] | [{{SERVER}}:20000/netdata.conf Configuration] | ||
netdata.conf --> | |||
== System Locations == | == System Locations == | ||
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to install, you'll get all of netdata installed into <code>/opt/netdata</code> | to install, you'll get all of netdata installed into <code>/opt/netdata</code> | ||
== With Ansible == | |||
There is an [https://learn.netdata.cloud/docs/netdata-agent/installation/ansible Ansible Playbook for deploying Netdata Agent] across multiple nodes. At that page, they also describe how to disable the local dashboard by setting <code>web_mode</code> to none. The security configuration is described at https://learn.netdata.cloud/docs/netdata-agent/configuration/securing-agents/ | |||
== Host Modifications == | == Host Modifications == | ||
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=== HAProxy === | === HAProxy === | ||
< | <syntaxhighlight lang="python"> | ||
frontend netdata | frontend netdata | ||
bind *:20000 ssl crt /etc/haproxy/certs/wiki.freephile.org.pem | bind *:20000 ssl crt /etc/haproxy/certs/wiki.freephile.org.pem | ||
| Line 41: | Line 45: | ||
backend netdata-back | backend netdata-back | ||
server nd1 127.0.0.1:19999 | server nd1 127.0.0.1:19999 | ||
</ | </syntaxhighlight> | ||
=== Kernel === | === Kernel === | ||
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You'll probably receive alarms for 'tcp listen drops'. This is likely bot-related (sending INVALID packets) and NOT due to your application dropping legitimate packets. There is a good discussion on how to identify the source of the problem and how to mitigate or resolve it [https://github.com/firehol/netdata/issues/3234 Issue #3234][https://github.com/firehol/netdata/issues/3826 Issue #3826] TLDR; increase the threshold to 1 (<code>/etc/netdata/health.d/tcp_listen.conf</code>) so you don't get bogus alerts. | You'll probably receive alarms for 'tcp listen drops'. This is likely bot-related (sending INVALID packets) and NOT due to your application dropping legitimate packets. There is a good discussion on how to identify the source of the problem and how to mitigate or resolve it [https://github.com/firehol/netdata/issues/3234 Issue #3234][https://github.com/firehol/netdata/issues/3826 Issue #3826] TLDR; increase the threshold to 1 (<code>/etc/netdata/health.d/tcp_listen.conf</code>) so you don't get bogus alerts. | ||
Also, you should modify your firewall to drop invalid packets before they're either counted (by | Also, you should modify your firewall to drop invalid packets before they're either counted (by netdata) or dropped (by the kernel). | ||
< | <syntaxhighlight lang="bash"> | ||
iptables -A INPUT -m conntrack --ctstate INVALID -j DROP | iptables -A INPUT -m conntrack --ctstate INVALID -j DROP | ||
ip6tables -A INPUT -m conntrack --ctstate INVALID -j DROP | ip6tables -A INPUT -m conntrack --ctstate INVALID -j DROP | ||
iptables -A INPUT -m tcp -p tcp ! --tcp-flags FIN,SYN,RST,ACK SYN -m conntrack --ctstate NEW -j DROP | iptables -A INPUT -m tcp -p tcp ! --tcp-flags FIN,SYN,RST,ACK SYN -m conntrack --ctstate NEW -j DROP | ||
ip6tables -A INPUT -m tcp -p tcp ! --tcp-flags FIN,SYN,RST,ACK SYN -m conntrack --ctstate NEW -j DROP | ip6tables -A INPUT -m tcp -p tcp ! --tcp-flags FIN,SYN,RST,ACK SYN -m conntrack --ctstate NEW -j DROP | ||
</ | </syntaxhighlight> | ||
Following the advice from NASA at https://wiki.earthdata.nasa.gov/display/HDD/SOMAXCONN, I increased my somaxconn kernel parameter to 1024 from 128 | Following the advice from NASA at https://wiki.earthdata.nasa.gov/display/HDD/SOMAXCONN, I increased my somaxconn kernel parameter to 1024 from 128 | ||
< | <syntaxhighlight lang="bash"> | ||
cat /proc/sys/net/core/somaxconn | cat /proc/sys/net/core/somaxconn | ||
128 | 128 | ||
sysctl -w net.core.somaxconn=1024 | sysctl -w net.core.somaxconn=1024 | ||
</ | </syntaxhighlight> | ||
[[File:Tcp state diagram fixed.svg|600px|TCP State diagram]] | [[File:Tcp state diagram fixed.svg|600px|TCP State diagram]] | ||
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ln -s /root/netdata/netdata-updater.sh /etc/cron.daily/netdata-updater | ln -s /root/netdata/netdata-updater.sh /etc/cron.daily/netdata-updater | ||
</code> | </code> | ||
{{References}} | |||
[[Category:QualityBox]] | [[Category:QualityBox]] | ||
[[Category:Monitoring]] | [[Category:Monitoring]] | ||
Latest revision as of 09:36, 15 September 2025
Netdata is one of the QualityBox dashboards.
System Locations[edit]
Depending on how you install netdata, it will be distributed in the normal system locations such as
- the daemon at /usr/sbin/netdata - config files in /etc/netdata - web files in /usr/share/netdata - plugins in /usr/libexec/netdata - cache files in /var/cache/netdata - db files in /var/lib/netdata - log files in /var/log/netdata - pid file at /var/run/netdata.pid - logrotate file at /etc/logrotate.d/netdata
Or, if you use
bash <(curl -Ss https://my-netdata.io/kickstart-static64.sh)
to install, you'll get all of netdata installed into /opt/netdata
With Ansible[edit]
There is an Ansible Playbook for deploying Netdata Agent across multiple nodes. At that page, they also describe how to disable the local dashboard by setting web_mode to none. The security configuration is described at https://learn.netdata.cloud/docs/netdata-agent/configuration/securing-agents/
Host Modifications[edit]
A Netdata role is available in the 32.x branch of Meza
Otherwise, you have to make room in HAProxy for netdata:
HAProxy[edit]
frontend netdata
bind *:20000 ssl crt /etc/haproxy/certs/wiki.freephile.org.pem
mode http
default_backend netdata-back
backend netdata-back
server nd1 127.0.0.1:19999Kernel[edit]
You have kernel memory de-duper (called Kernel Same-page Merging, or KSM) available, but it is not currently enabled.
Memory de-duplication instructions
To enable it run:
echo 1 >/sys/kernel/mm/ksm/run echo 1000 >/sys/kernel/mm/ksm/sleep_millisecs
If you enable it, you will save 40-60% of netdata memory.
Ports[edit]
netdata by default listens on all IPs on port 19999. We add a rule to firewalld to allow 20000 and then pass that port through to the backend in haproxy config.
http://this.machine.ip:20000/ => http://127.0.0.1:19999
Start/Stop[edit]
To stop netdata run:
systemctl stop netdata
To start netdata run:
systemctl start netdata
To reload configuration:
killall -USR2 netdata [1]
Notifications[edit]
The default configuration will send messages to 'root' so be sure to either edit the conf sudo vim /etc/netdata/health_alarm_notify.conf, or set vim /etc/aliases && newaliases
Turn off alarm[edit]
to: silent # silence notification; still see on website enabled: no # disable alarm
more details in the netdata docs.
Issues[edit]
You'll probably receive alarms for 'tcp listen drops'. This is likely bot-related (sending INVALID packets) and NOT due to your application dropping legitimate packets. There is a good discussion on how to identify the source of the problem and how to mitigate or resolve it Issue #3234Issue #3826 TLDR; increase the threshold to 1 (/etc/netdata/health.d/tcp_listen.conf) so you don't get bogus alerts.
Also, you should modify your firewall to drop invalid packets before they're either counted (by netdata) or dropped (by the kernel).
iptables -A INPUT -m conntrack --ctstate INVALID -j DROP
ip6tables -A INPUT -m conntrack --ctstate INVALID -j DROP
iptables -A INPUT -m tcp -p tcp ! --tcp-flags FIN,SYN,RST,ACK SYN -m conntrack --ctstate NEW -j DROP
ip6tables -A INPUT -m tcp -p tcp ! --tcp-flags FIN,SYN,RST,ACK SYN -m conntrack --ctstate NEW -j DROPFollowing the advice from NASA at https://wiki.earthdata.nasa.gov/display/HDD/SOMAXCONN, I increased my somaxconn kernel parameter to 1024 from 128
cat /proc/sys/net/core/somaxconn
128
sysctl -w net.core.somaxconn=1024
Updates[edit]
Netdata will update itself, and puts a script into cron:
ln -s /root/netdata/netdata-updater.sh /etc/cron.daily/netdata-updater
