Difference between revisions of "Netdata"
m (not 'stats'; data) |
(Adds firewall config) |
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== Installation extras == | == Installation extras == | ||
| + | |||
The configuration will send messages to 'root' so be sure to either edit the conf <code>sudo vim /etc/netdata/health_alarm_notify.conf</code>, or set <code>vim /etc/aliases && newaliases</code> | The configuration will send messages to 'root' so be sure to either edit the conf <code>sudo vim /etc/netdata/health_alarm_notify.conf</code>, or set <code>vim /etc/aliases && newaliases</code> | ||
| − | You'll probably receive alarms for 'tcp listen drops'. This is likely bot-related | + | == Issues == |
| + | |||
| + | 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 netstats) or dropped (by the kernel). | ||
| + | |||
| + | <source lang="bash"> | ||
| + | iptables -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 | ||
| + | </source> | ||
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 | ||
Revision as of 15:48, 30 August 2018
Netdata will be part of the QualityBox dashboard.
See http://wiki.freephile.org:20000/
Contents
System Locations[edit | edit source]
- 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
Host Modifications[edit | edit source]
HAProxy[edit | edit source]
frontend netdata
bind *:20000
mode http
default_backend netdata-back
backend netdata-back
server nd1 127.0.0.1:19999
Kernel[edit | edit source]
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 | edit source]
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 | edit source]
To stop netdata run:
systemctl stop netdata
To start netdata run:
systemctl start netdata
Installation extras[edit | edit source]
The 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
Issues[edit | edit source]
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 #3234 Issue #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 netstats) or dropped (by the kernel).
iptables -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
Following 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 | edit source]
Netdata will update itself, and puts a script into cron:
ln -s /root/netdata/netdata-updater.sh /etc/cron.daily/netdata-updater
