Ethereum Dropped Transactions

[bambam]

A transaction that was previously broadcasted on the network (but yet to be included in a block) can get dropped from the connected nodes. This happens more frequently during times when the network is busy.



There are a number of reasons for this:



1) The Ethereum nodes (i.e Geth/Parity) that we are connected to has dropped the Pending transaction from the transaction pool (most likely due to a lower gas price compared to other pending transactions or other limits being hit).



2) There is a maximum amount of Pending transactions an Ethereum node can hold before certain transactions are dropped from its pending pool (this depends on the various settings/limits of the individual clients connected to the network).



3) If a dropped transaction is not re-broadcasted, it will not be included in a block. If this happens it would be as if the transaction had not taken place at all.



4) If a dropped transaction is successfully re-broadcasted either directly or indirectly (by a different node) then it will  re-appear as a Pending transaction.



5) For further assistance on dropped transactions please contact the sender/creator of the transaction (i.e your exchange, wallet provider, etc)