Bitcoin price surge brought with it unwanted spike in transaction queue that reached 18MB in size that not only led to increase in congestion in the network, but also left some bitcoiners suddenly stranded without recourse.
Bitcoin transaction fees spiked to around $2 just before a difficulty adjustment and this forced transactions out of the queue as new ones were made with far higher fees, thus gaining priority for the very limited 1MB (~2,000 transactions) space. The reasons behind this are not clear, however, some possibilities are noted below.
One of the reasons is believed to be many transactions being suddenly performed by one entity – an act that is being equated to spamming – They call it spam, by which presumably they mean the transactions were not intended to transfer value, but for something else.
Today’s spike seems minuscule, even though fees have considerably increased as stated earlier. As such, it may well be the case that rather than one entity, the congestion increased because, firstly it is Monday and the start of a new working day, and secondly, as well as more importantly, because mining difficulty increased by 20%.
Technically, if no new hashrate is added to the network, then blocks would be found more slowly. With the network already near limits, the slow down in processing speed may have instantly created that spike, followed by the increase in fees.
This unpredictability and very sudden network processing speed adjustment may make the maintenance of a fee market difficult if at all possible, with increases and decreases being cyclic.
As such, if this was an attack or otherwise, it may well be the case that both sides can agree it is a vulnerability for the network which is currently operating at full capacity.