doc/app_netdata.md

NetData

NetData is a system for distributed real-time performance and health monitoring. It provides unparalleled insights, in real-time, of everything happening on the system it runs (including applications such as web and database servers), using modern interactive web dashboards.

netdata is fast and efficient, designed to permanently run on all systems (physical & virtual servers, containers, IoT devices), without disrupting their core function.

Customization brought by the package:

• grant MySQL statistics access via a netdata user
• nginx root log statistics via putting netdata user in the adm group
• Dovecot statistics via giving access to Dovecot stats stocket to netdata user (works only with Dovecot 2.2.16+)

Further recommendations: We don't allow YunoHost packages to make sensible changes to system files. So here are further customizations you can make to allow more monitoring:

• Nginx:
  • requests/connections: follow these recommandations to enable /stab_status (for example by putting the location section in /etc/nginx/conf.d/yunohost_admin.conf
  • weblogs: you can monitor all your nginx weblogs for errors; follow these recommendations
• phpfpm: follow these recommandations

Features

• Stunning interactive bootstrap dashboards
  mouse and touch friendly, in 2 themes: dark, light

• Amazingly fast
  responds to all queries in less than 0.5 ms per metric, even on low-end hardware

• Highly efficient
  collects thousands of metrics per server per second, with just 1% CPU utilization of a single core, a few MB of RAM and no disk I/O at all

• Sophisticated alarming
  hundreds of alarms, out of the box!
  supports dynamic thresholds, hysteresis, alarm templates, multiple role-based notification methods (such as email, slack.com, pushover.net, pushbullet.com, telegram.org, twilio.com, messagebird.com)

• Extensible
  you can monitor anything you can get a metric for, using its Plugin API (anything can be a netdata plugin, BASH, python, perl, node.js, java, Go, ruby, etc)

• Embeddable
  it can run anywhere a Linux kernel runs (even IoT) and its charts can be embedded on your web pages too

• Customizable
  custom dashboards can be built using simple HTML (no javascript necessary)

• Zero configuration
  auto-detects everything, it can collect up to 5000 metrics per server out of the box

• Zero dependencies
  it is even its own web server, for its static web files and its web API

• Zero maintenance
  you just run it, it does the rest

• scales to infinity
  requiring minimal central resources

• several operating modes
  autonomous host monitoring, headless data collector, forwarding proxy, store and forward proxy, central multi-host monitoring, in all possible configurations. Each node may have different metrics retention policy and run with or without health monitoring.

• time-series back-ends supported
  can archive its metrics on graphite, opentsdb, prometheus, json document DBs, in the same or lower detail (lower: to prevent it from congesting these servers due to the amount of data collected)

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What does it monitor?

netdata collects several thousands of metrics per device. All these metrics are collected and visualized in real-time.

Almost all metrics are auto-detected, without any configuration.

This is a list of what it currently monitors:

• CPU
  usage, interrupts, softirqs, frequency, total and per core, CPU states

• Memory
  RAM, swap and kernel memory usage, KSM (Kernel Samepage Merging), NUMA

• Disks
  per disk: I/O, operations, backlog, utilization, space, software RAID (md)

  

• Network interfaces
  per interface: bandwidth, packets, errors, drops

  

• IPv4 networking
  bandwidth, packets, errors, fragments, tcp: connections, packets, errors, handshake, udp: packets, errors, broadcast: bandwidth, packets, multicast: bandwidth, packets

• IPv6 networking
  bandwidth, packets, errors, fragments, ECT, udp: packets, errors, udplite: packets, errors, broadcast: bandwidth, multicast: bandwidth, packets, icmp: messages, errors, echos, router, neighbor, MLDv2, group membership, break down by type

• Interprocess Communication - IPC
  such as semaphores and semaphores arrays

• netfilter / iptables Linux firewall
  connections, connection tracker events, errors

• Linux DDoS protection
  SYNPROXY metrics

• fping latencies
  for any number of hosts, showing latency, packets and packet loss

  

• Processes
  running, blocked, forks, active

• Entropy
  random numbers pool, using in cryptography

• NFS file servers and clients
  NFS v2, v3, v4: I/O, cache, read ahead, RPC calls

• Network QoS
  the only tool that visualizes network tc classes in realtime

  

• Linux Control Groups
  containers: systemd, lxc, docker

• Applications
  by grouping the process tree and reporting CPU, memory, disk reads, disk writes, swap, threads, pipes, sockets - per group

  

• Users and User Groups resource usage
  by summarizing the process tree per user and group, reporting: CPU, memory, disk reads, disk writes, swap, threads, pipes, sockets

• Apache and lighttpd web servers
  mod-status (v2.2, v2.4) and cache log statistics, for multiple servers

• Nginx web servers
  stub-status, for multiple servers

• Tomcat
  accesses, threads, free memory, volume

• web server log files
  extracting in real-time, web server performance metrics and applying several health checks

• mySQL databases
  multiple servers, each showing: bandwidth, queries/s, handlers, locks, issues, tmp operations, connections, binlog metrics, threads, innodb metrics, and more

• Postgres databases
  multiple servers, each showing: per database statistics (connections, tuples read - written - returned, transactions, locks), backend processes, indexes, tables, write ahead, background writer and more

• Redis databases
  multiple servers, each showing: operations, hit rate, memory, keys, clients, slaves

• mongodb
  operations, clients, transactions, cursors, connections, asserts, locks, etc

• memcached databases
  multiple servers, each showing: bandwidth, connections, items

• elasticsearch
  search and index performance, latency, timings, cluster statistics, threads statistics, etc

• ISC Bind name servers
  multiple servers, each showing: clients, requests, queries, updates, failures and several per view metrics

• NSD name servers
  queries, zones, protocols, query types, transfers, etc.

• Postfix email servers
  message queue (entries, size)

• exim email servers
  message queue (emails queued)

• Dovecot POP3/IMAP servers
  

• ISC dhcpd
  pools utilization, leases, etc.

• IPFS
  bandwidth, peers

• Squid proxy servers
  multiple servers, each showing: clients bandwidth and requests, servers bandwidth and requests

• HAproxy
  bandwidth, sessions, backends, etc

• varnish
  threads, sessions, hits, objects, backends, etc

• OpenVPN
  status per tunnel

• Hardware sensors
  lm_sensors and IPMI: temperature, voltage, fans, power, humidity

• NUT and APC UPSes
  load, charge, battery voltage, temperature, utility metrics, output metrics

• PHP-FPM
  multiple instances, each reporting connections, requests, performance

• hddtemp
  disk temperatures

• smartd
  disk S.M.A.R.T. values

• SNMP devices
  can be monitored too (although you will need to configure these)

• statsd
  netdata is a fully featured statsd server

And you can extend it, by writing plugins that collect data from any source, using any computer language.

Links

• Report a bug: https://github.com/YunoHost-Apps/netdata_ynh/issues
• NetData website: http://my-netdata.io/