All My Transactions Since Friday Are Still Pending

Question

I've been having a real bad time with Mist and the Ethereum Wallet as no transactions at all are getting confirmed are just pending.

My client is fully synced and displays the same block number as shown on Etherscan.

On Friday evening, I created a token contract. I paid a below average amount of gas and was prepared to wait. It's now Sunday and nothing.

On Saturday, I created some more contracts and paid the suggested amount of Wei as well as the highest amount to see if they went through. Today, they're still all pending.

I also tried sending Ether from one account to another several times, selecting different amounts of Gas to see if that works. Still nothing.

The funny thing is, when I sent a transaction from MyEtherWallet to my Waves Ether Wallet using the same account, that transaction went through.

So I know that my wallet can send transactions and that the Waves wallet works, but when I send some more Ether to Waves, but this time through my client, it just pends like everything else.

However when I send a transaction from MEW to another of my accounts on my computer, it just sits at pending indefinitely as well. Strange.

This is my main wallet address: https://etherscan.io/address/0x7b9b1355c33f38be4683a183c194ebb91a289978

You'll see all the pending transactions which I am talking about. Most of those have been like that for well over 24 hours now.

I am able to receive Ether though with no problems.

Any ideas? Should I be worried it will they eventually go through?

Answer 1

Let me explain how transaction are created so I can explain the problem.

To avoid transaction malleability each Ethereum transaction includes a sequence number called nonce. The very first transaction from an account has nonce equal to zero, and subsequent transactions are the previous plus one.

If two or more transactions have the same nonce, only one will be mined and the other will be discarded. Some miners will priviledge transactions having a higher gas price.

To create a transaction a wallet will query an Ethereum node for the last transaction and will set the nonce value accordingly. A wallet may also cache the last nonce used, so you can send several transaction without having to wait for the previous transactions have been mined.

The problems appears when a transaction has a very low gas price. It can take a some time until it is mined, and it will block later transactions.

If you create a transaction from a different wallet, for example from MyEtherWallet. They will use the last mined transaction to calculate the nonce and it will replace the transaction with low gas price.