Ethereum world state monitoring

1. Ethereum blockchain has exposed three major problems, and its founder vitalik buterin has been unable to interpret them for a long time. The first is the low performance and TPS of Ethereum blockchain as a whole; The second is that resources are not isolated. The event of cryptokitties virtual cat once occupied 20% of the traffic of the whole Ethereum, which directly caused Ethereum network users unable to carry out timely transactions, which is the biggest pain point of resources not isolated; The third problem lies in the embodiment of Ethereum's governance structure. As a decentralized distributed ledger, the founder team of Ethereum has dominated its network development in the past. The over centralized governance mode has led to the bifurcation of eth, etc and ETF in Ethereum, and the Ethereum community is now in a state of fragmented governance. In the view of Ma Haobo, founder and CEO of "aelf", all kinds of disadvantages of Ethereum are unacceptable. Therefore, the positioning of "aelf" is born for the next generation of decentralized underlying computing platform of Ethereum, which focuses on solving the problems of insufficient performance, non isolation of resources and governance structure of Ethereum.

2.

Hangzhou Ethereum Information Technology Co., Ltd. is a limited liability company (invested or controlled by natural person) registered in Yuhang District, Hangzhou City, Zhejiang Province on March 20, 2017. Its registered address is room 2003, building 3, Xinyuan jinzuo, Nanyuan street, Yuhang District, Hangzhou City, Zhejiang Province (entrusted by Tianze commercial secretary)

the unified social credit code / registration number of Hangzhou Ethereum Information Technology Co., Ltd. is 91330110ma28n029xm, and the enterprise legal person is Zhang Shoukun

Hangzhou Ethereum Information Technology Co., Ltd. has a general registered capital in the province

view more information and information of Hangzhou Ethereum Information Technology Co., Ltd. through network enterprise credit

3.

If you want to query the transaction records on the main network, you can use Etherscan. However, if you build your own private chain, how should you query the transaction records

the answer is that you need to listen to the logs on the chain, save them in the database, and then query them in the database. For example:

< pre t = "code" L = "Java" > varaddr = & quot& quot;< br />varfilter=web3.eth.filter({fromB lock:0 ,toBlock:' latest', address:addr });< br />filter.get(function(err,transactions){
transactions.forEach(function(tx){
vartxInfo=web3.eth.getTransaction(tx.transactionHash);
/ / at this time, the transaction information txinfo can be stored in the database
})< br />});

Web3. Eth. Filter() is used to monitor the log on the chain, and Web3. Eth. Gettransaction() is used to extract the information of the specified transaction. Once the transaction information is obtained, it can be stored in the database for query

recommend a practical introction, you can see: Ethereum tutorial

4. Ethereum is an open source public blockchain platform with smart contract function. It provides decentralized virtual machine (Ethereum virtual machine) to process point-to-point contract through its special cryptocurrency Ethereum
the concept of Ethereum was first proposed by vitalik buterin, a programmer, from 2013 to 2014, inspired by bitcoin, to the effect of "next generation cryptocurrency and decentralized application platform". It began to develop through ICO crowdfunding in 2014<

OAS is the world's first blockchain environmental protection technology and energy management system issued by oases. It is jointly released and established by Singapore oases foundation and EPC foundation of the United States. It aims to solve the problem of how to rece environmental pollution, rece energy consumption and monitor emissions worldwide by using blockchain technology and combining with real economy instry, And the collection of environmental big data and other issues to provide a perfect solution to build a more environmentally friendly and energy-saving world
in comparison, although OAS is later than Ethereum, its innovative combination of blockchain and environmental protection has a better development prospect.

5.

Xiamen Ethereum Technology Co., Ltd. is a limited liability company (invested or controlled by natural person) registered in Siming District, Xiamen City, Fujian Province on March 5, 2018. Its registered address is located at unit 901c, Fuxing building, 73 Tainan Road, Siming District, Xiamen city

the unified social credit code / registration number of Xiamen Ethereum Technology Co., Ltd. is 91350203ma31hb9p81, and Xu Fusheng, the legal person of the company, is currently in business

in Xiamen Ethereum Technology Co., Ltd., the current registered capital of the enterprise is general

view more information and information of Xiamen Ethereum Technology Co., Ltd. through network enterprise credit

6. Most of Linux users are developers and researchers, and servers are also used more
windows, making money first
it's hard to say who is strong. It's estimated that no one will convince anyone!

7. Here are the command names by function
monitor the overall bandwidth usage - nload, bmon, slurm, BWM ng, CBM, speedometer and netload
monitor the overall bandwidth usage (batch output) - vnstat, ifstat, dstat and collect
the bandwidth usage of each socket connection - iftop, iptraf, tcptrack, pktstat Netwatch and trafhow
bandwidth usage of each process -- nethogs
1. Nload

nload is a command-line tool that allows users to monitor inbound and outbound traffic separately. It can also draw charts to show inbound and outbound traffic, and the view scale can be adjusted. It's easy to use and doesn't support many options
therefore, if you only need to quickly view the total bandwidth usage, and do not need the details of each process, nload is very convenient to use
$nload

install nload: Fedora and Ubuntu have nload in the default software library. CentOS users need to obtain nloads from the EPEL software library
# Fedora or CentOS $Yum install nload - y # Ubuntu / Debian $sudo apt get install nload

2. Iftop
iftop can measure the data transmitted through each socket connection; It works differently from nload. Iftop uses pcap library to capture the packets in and out of the network adapter, and then summarizes the packet size and number to find out the total bandwidth usage
although iftop reports the bandwidth used by each connection, it cannot report the process name / number (ID) participating in a nested word connection. However, based on the pcap library, iftop can filter traffic and report the bandwidth usage of the selected host connection specified by the filter
$sudo iftop - N

n option can prevent iftop from resolving IP address to host name, which will bring extra network traffic

install iftop: Ubuntu / Debian / Fedora users can get it from the default software library. CentOS users can get it from EPEL
# Fedora or CentOS Yum install iftop - y # Ubuntu or Debian $sudo apt get install iftop

3. Iptraf
iptraf is an interactive and colorful IP LAN monitoring tool. It can display the amount of data transferred between each connection and between hosts. Here is a screen shot

$sudo iptraf

install iptraf:
# CentOS (basic software library) $Yum install iptraf # Fedora or CentOS (with EPEL) $Yum install iptraf ng - y # Ubuntu or Debian $sudo apt get install iptraf iptraf ng

4. Nethogs
nethogs is a compact & quot; net top" Tool, which can display the bandwidth used by each process, sort the list, and rank the process that consumes the most bandwidth at the top. In case of a sudden surge in bandwidth usage, users can quickly open nethogs to find the process that causes the surge in bandwidth usage. Nethogs can report the process number (PID), user and path of the program
$sudo nethogs

install nethogs: users of Ubuntu, Debian and fedora can get it from the default software library. CentOS users need EPEL
# Ubuntu or Debian (default software library) $sudo apt get install nethogs # Fedora or CentOS (from EPEL) $sudo Yum install nethogs - y

5. Bmon
bmon (bandwidth monitor) is a nload like tool, which can display the traffic load of all network interfaces on the system. The output also contains charts and sections with detailed information at the packet level

install bmon: users of Ubuntu, Debian and fedora can install it from the default software library. CentOS users need to install repoforge because there is no bmon in EPEL
# Ubuntu or Debian $sudo apt get install bmon # Fedora or CentOS (from repoforge) $sudo Yum install bmon

bmon supports many options and can proce HTML reports. For more information, see the reference man page
6. Slurm
slurm is another network load monitor, which can display the statistical information of the device and also display ASCII graphics. It supports three different types of graphics, each of which can be activated by using the C key, s key and l key. Slurm is simple and cannot display any further details about the network load
$slurm - S - I eth0

install slurm
# Debian or Ubuntu $sudo apt get install slurm # Fedora or CentOS $sudo Yum install slurm - y

7. Tcptrack
tcptrack is similar to iftop. Pcap library is used to capture packets and calculate various statistical information, such as the bandwidth used by each connection. It also supports standard pcap filters that can be used to monitor specific connections

install tcptrack: Ubuntu, Debian and fedora have it in the default software library. CentOS users need to get it from repoforge because it is not in EPEL
# Ubuntu, Debian $sudo apt get install tcptrack # Fedora, CentOS (from repoforge software library) $sudo Yum install tcptrack

8. Vnstat
vnstat is a little different from most other tools. It actually runs background services / daemons and keeps track of the size of the data transferred. In addition, it can be used to proce reports showing the history of network usage
$service vnstat status * vnstat daemon is running

running vnstat without any options will only display the total amount of data transferred since the daemon has been running< br />$ vnstat Database updated: Mon Mar 17 15:26:59 2014 eth0 since 06/12/13 rx: 135.14 GiB tx: 35.76 GiB total: 170.90 GiB monthly rx | tx | total | avg. rate ------------------------+-------------+-------------+------------- Feb ' 14 8.19 GiB | 2.08 GiB | 10.27 GiB | 35.60 kbit/s Mar ' 14 4.98 GiB | 1.52 GiB | 6.50 GiB | 37.93 kbit/s ------------------------+-------------+-------------+------------- estimated 9.28 GiB | 2.83 GiB | 12.11 GiB | daily rx | tx | total | avg. rate ------------------------+-------------+-------------+------------- yesterday 236.11 MiB | 98.61 MiB |334.72 MIB | 31.74 kbit / s today 128.55 MIB | 41.00 MIB | 169.56 MIB | 24.97 kbit / S- l" Option (real time mode). It then shows the total amount of bandwidth used by inbound and outbound data, but very precisely, without any internal details about host connections or processes
$vnstat - L - I eth0 monitoring eth0... (press ctrl-c to stop) Rx: 12 kbit / s 10 P / s TX: 12 kbit / S 11 P / s

vnstat is more like a tool for making historical reports, showing how much bandwidth is used every day or in the past month. It is not strictly a tool for real-time monitoring network
vnstat supports many options. Please refer to the manual page for details of which options are supported
install vnstat
# Ubuntu or Debian $sudo apt get install vnstat # Fedora or CentOS (from EPEL) $sudo Yum install vnstat

9. BWM ng
BWM ng (next generation bandwidth monitor) is another very simple real-time network load monitoring tool, which can report summary information, Displays the transmission speed of different data in and out of all available network interfaces on the system< br />$ bwm-ng bwm-ng v0.6 (probing every 0.500s), press ' h' for help input: /proc/net/dev type: rate / iface Rx Tx T ot================================================================= == eth0: 0.53 KB/s 1.31 KB/s 1.84 KB lo: 0.00 KB/s 0.00 KB/s 0.00 KB----------- --------------------------------------------------------------------------------------------------Total: 0.53 KB / s 1.31 KB / s 1.84 KB / s

if the console is large enough, BWM ng can also use curses2 output mode to draw bar graph for traffic
$BWM ng - O curses2

install BWM ng: on CentOS, you can install BWM ng from EPEL
# Ubuntu or Debian $sudo apt get install BWM ng # Fedora or CentOS (from EPEL) $sudo apt get install BWM ng

10. CBM: color bandwidth meter

this is a small and simple bandwidth monitoring tool, which can display the traffic through various network interfaces. No further options, just real-time display and update traffic statistics
$sudo apt get install CBM

11. Speedometer
this is another small and simple tool, which only draws beautiful graphics to show the inbound and outbound traffic transmitted through a certain interface
$speedometer - R eth0 - t eth0

installing speedometer
$subuntu or Debian user $sudo apt get install speedometer

12. Pktsat

pktsat can display all active connections in real time and show which data is transmitted through these active connections at the speed. It can also display the connection type, such as TCP connection or UDP connection; If an HTTP connection is involved, details about the HTTP request are also displayed
$sudo pktstat - I eth0 - NT $sudo apt get install pktstat

13. Netwatch

netwatch is a part of netdiag tool library. It can also display the connections between the local host and other remote hosts, and display which data is transmitted at the speed of each connection
$sudo netwatch - e eth0 - NT $sudo apt get install netdiag

14. Trafshow
like netwatch and pktstat, trafshow can also report the current active connections, the protocols they use, and the data transfer speed on each connection. It can use pcap type filter to filter the connection
only monitor TCP connections

$sudo trafshow - I eth0 TCP $sudo apt get install netdiag

15. Netload
the netload command displays only a short report on the current traffic load and the total number of bytes transmitted since the program was started. There are no more features. It's part of netdiag

$netload eth0 $sudo apt get install netdiag

16. Ifstat
ifstat can display network bandwidth in batch mode. Output in a format that allows users to log and analyze using other programs or utilities
$ifstat - t - I eth0 0.5 time eth0 HH: mm: SS KB / s in KB / s out 09:21 2.62 2.80 09:59:22 2.10 1.78 09:22 2.67 1.84 09:59:23 2.06 1.98 09:59:23 1.73 1.79

install ifstat: Ubuntu, Debian and fedora users have it in the default software library. CentOS users need to get it from repoforge because it is not in EPEL< br /># ubuntu, debian $ sudo apt-get install ifstat # fedora, centosRe