Some transactions are missing receipt

Question

I am inspecting a strange case. I am monitoring Ropsten network for my project and writing all transactions to database to search them though in much more convenient way. Every couple of minutes I schedule a worker that checks database for records with pending status and try to retriever transaction receipts from block chain. I noticed that there were some old transactions but without transaction receipt at all. Searching for transaction hash on ropsten.etherscan.io gave no results. Here is an example

> var Web3 = require('web3');
> var web3 = new Web3("ws://127.0.0.1:858");
> web3.eth.getTransaction('0xa47ae1f88626e0534382a980aa96db212225abd7570817aecac1f30276ed431e').then(console.log);
{ blockHash: null,
  blockNumber: null,
  chainId: '0x3',
  condition: null,
  creates: null,
  from: '0x01592cE6b6dcd5D5fe9933d7b6a6786A79274CD3',
  gas: 121000,
  gasPrice: '4000000000',
  hash: '0xa47ae1f88626e0534382a980aa96db212225abd7570817aecac1f30276ed431e',
  input: '0x',
  nonce: 53,
  publicKey: '0x772bac5a49059e6648ab2dfd0d4349ba84c9a3d3d9cd84abf67e4966eebc02145638a8e6d5fd9798072d2bdd27fd2a360192d3587a7e2cb62c193124a65cf413',
  r: '0x9ed44eb37c1da71d600afee3c9a1283ed0d259dfe7c1ee00e9a16fd0e2678bed',
  raw: '0xf86b3584ee6b28008301d8a89412fa13c638b4b6ceb1ac1c8d072530abd5a18fbc872386f26fc100008029a09ed44eb37c1da71d600afee3c9a1283ed0d259dfe7c1ee00e9a16fd0e2678beda059f1788c8e38373abf4ea0b6ca4ad5c3014dcca29c17657c195405422c8a6913',
  s: '0x59f1788c8e38373abf4ea0b6ca4ad5c3014dcca29c17657c195405422c8a6913',
  standardV: '0x0',
  to: '0x12FA13C638b4b6Ceb1aC1C8d072530AbD5A18FbC',
  transactionIndex: null,
  v: '0x29',
  value: '10000000000000000' }
> web3.eth.getTransactionReceipt('0xa47ae1f88626e0534382a980aa96db212225abd7570817aecac1f30276ed431e').then(console.log);
null

This transaction arrived to my local DB at 2:30 AM my local time and I stared my investigation at 10am. By the time I started my investigation it was pending for 7 hours at least. Also Etherscan shows pending transaction on their webpage if transaction is yet to be mined, in case of this transaction Etherscan seems to be unaware of it. Here is what etherscan shows

https://ropsten.etherscan.io/tx/0xa47ae1f88626e0534382a980aa96db212225abd7570817aecac1f30276ed431e

AS you can see from transaction data it has correct amount of gas and gas price: 121k for 4MGwei. Can someone explain this behavior?

UPDATE

The explanation for this behavior is answered here: Are pending transactions "dropped" and "reinstated"?

Answer 1

web3.eth.getTransactionReceipt

works only for successfully mined transactions. At time of writing, the

0xa47ae1f88626e0534382a980aa96db212225abd7570817aecac1f30276ed431e

you mentioned is still pending (a.k.a. not mined yet) and therefore cannot be inspected with the command above.