Linux性能实时监测工具-Netdata，它是Linux系统实时性能监测工具，以web的可视化方式展示系统及应用程序的实时运行状态（包括cpu、内存、硬盘输入/输出、网络等linux性能的数据）。Netdata的web前端响应很快，而且不需要Flash插件。 UI很整洁，保持着 Netdata 应有的特性。第一眼看上去，你能够看到很多图表，幸运的是绝大多数常用的图表数据（像 CPU，RAM，网络和硬盘）都在顶部。如果你想深入了解图形化数据，你只需要下滑滚动条，或者点击在右边菜单的项目。通过每个图表的右下方的按钮，Netdata还能控制图表的显示，重置，缩放
Netdata用可视化的手段，将被监测者最细微的细节，展现了出来。这样便可以清晰地了解linux系统和应用程序此时的状况
优美的界面：bootstrap框架下的控制界面
自定义的控制界面：你可以使用简单的HTML代码去自定义控制界面(不需要使用javascript)
极其的快速而高效：程序使用C进行编写(默认安装下，预计只有2%的单核CPU使用率和少许的内存使用率)
零配置：你只需要去安装它，接着它就会自动地监测一切数据
零依赖：它的静态网络文件和网络接口拥有自己的网络服务器
可扩展：用它自身的插件API(可以使用许多方式来制作它的插件，从bash到node.js),你可以检测任何可以衡量的数据。
可嵌入：它可以在任何Linux内核可以运行的地方运行
监测内容：下面是Netdata目前检测的内容（大多数都不需要进行配置，安装后即可开始监测）
1.CPU的使用率,中断，软中断和频率(总量和每个单核)
2.RAM，互换和内核内存的使用率（包括KSM和内核内存deduper）
3.硬盘输入/输出(每个硬盘的带宽，操作，整理，利用等)
4.IPv4网络（数据包，错误，分片）：
TCP：连接，数据包，错误，握手
UDP:数据包，错误
广播：带宽，数据包
组播：带宽，数据包
5.Netfilter/iptables Linux防火墙(连接，连接跟踪事件，错误等)
6.进程(运行，受阻，分叉，活动等)
7.NFS文件服务器，v2,v3,v4(输入/输出，缓存，预读，RPC调用)
8.网络服务质量（唯一一个可实时可视化网络状况的工具）
9.应用程序，通过对进程树进行分组（CPU,内存，硬盘读取，硬盘写入，交换，线程，管道，套接字等）
10.Apache Web服务器状态(v2.2, v2.4)
11.Nginx Web服务器状态
12.Mysql数据库（多台服务器，单个显示：带宽，查询/s, 处理者，锁，问题，临时操作，连接，二进制日志，线程，innodb引擎等）
13.ISC Bind域名服务器（多个服务器，单个显示：客户，请求，查询，更新，失败等）
14.Postfix邮件服务器的消息队列（条目，大小）
15.Squid代理服务器（客户带宽和请求，服务带宽和请求）
16.硬件传感器（温度，电压，风扇，电源，湿度等）
17.NUT UPSes（负载，充电，电池电压，温度，使用指标，输出指标）
可以监测任意数量的SNMP服务，不过你需要进行配置，还可以对此软件进行扩展，可以使用任何语言编写插件，以此来从任何来源收集数据
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 networktcclasses 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_sensorsandIPMI: 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