Ethereum RPC security

1. At the top of Ethereum is DAPP. It exchanges with the smart contract layer through Web3. JS. All smart contracts run on EVM (Ethereum virtual machine) and use RPC calls. Below EVM and RPC are the four core contents of Ethereum, including: blockchain, consensus algorithm, mining and network layer. Except DAPP, all other parts are in the Ethereum client. The most popular Ethereum client is geth (go Ethereum)

2. How to run Ethereum source code go Ethereum
install MIPS based Linux header file
$CD $prjroot / kernel
$tar - xjvf linux-2.6.38. Tar. Bz2
$CD linux-2.6.38

create an include folder under the specified path to store related header files< br />$ mkdir -p $TARGET_ Prefix / include

ensures that the Linux source code is clean
$make mrproper

generates the required header file< br />$ make ARCH=mips headers_ check
$ make ARCH=mips INSTALL_ HDR_ PATH=dest headers_ Install

all the files in dest folder to the specified include folder< br />$ cp -rv dest/include/* $TARGET_ Prefix / include

delete dest folder at last
$RM - RF dest
$LS - L $target_ PREFIX/include

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. Because blockchain technology has natural advantages in realizing smart contracts. bitcoin, Ruitai, Laite, Ethereum and other digital cryptocurrencies all use blockchain technology. Blockchain is an important concept of bitcoin. In essence, it is a decentralized database and the underlying technology of bitcoin. Blockchain is a chain of uses

5. I think it doesn't matter if it's a winter camp without money, but if it's for profit, it's problematic.

6. unwanted. I think it's too troublesome for the hospital to see a doctor. There are too many people waiting in the registration queue. If you have a small problem, you can directly use the app.

7. If it's Daling town in Yushu: 1. Go left from Changchun station, go to dongsantiao, take the bus to Yushu, and then transfer to Daling. 2: Take the bus from Changchun to Yushu to Qingshan at 5:30 a.m. to dongsantiao and get to dalingxia. The ticket price is 41 yuan. 3: Go left from Changchun station to East Square, take the bus from Changchun to Qingshan or Yumin, and get to dalingxia. The ticket price is 41 yuan. The bus of Wuchang mentioned above is not the same route as that of Daling at all.

8. Have social security card, need not ID card also can! Now most of the people who go to the hospital have to make an appointment. You can make an appointment on wechat first, and you won't be afraid of not getting the number

9. It's more than two hours. Take Wuchang bus and Huaide bus to pass Daling.