Transactions not going through(Rinkeby testnet)

Question

I'm new to Ethereum development. I set up the mist Ethereum wallet with rinkeby testnet for contract deployment. All worked good I could send transactions and write to the smart contract but at some point my transactions stopped going thru. They are stuck at pending status.

Why are my transactions not going through? How can I troubleshoot issues like this in the future?

Example of transactions that are not being accepted:executing a smart contract

My address https://rinkeby.etherscan.io/address/0x3b28b9547633ecebb76a6e3d47f5b2b6a22d85a9

Four days ago all transactions were accepted but none of my transacations since are going through.

edit: Seems like the transactions I have been doing for the past 3 days just went through. Does it mean my transactions were in the pool for 3 days?

Answer 1

To trouble shoot, you could check if any new blocks get added, from geth prompt read eth.blockNumber value to check if the blockheight is progressing at all. Also you could check to see if you are connected to any peer on the network; from the geth prompt you could test this by checking the value of admin.peers

Answer 2

Rinkeby uses proof of authority(POA) instead of proof of work(POW). This means that instead of waiting for miners to mine your transaction you are waiting for a trusted entity to push your transaction through.

https://ethereum.stackexchange.com/a/37497/7340