user93: What caused the huge drop of the mempool from 60 MB to Less then 1 MB?
These transaction didn't get processed there was no 60 MB block mined at the time.
This occurred at 10:38 pm 29th August 2017 NZ time


user5406: It looks like the node whose mempool size is used to generate this chart was rebooted. Also, this node appears to be running an old version of Core or another node software, because recent versions of Core persist the mempool across restarts.
Also see: 
How do transactions leave the memory pool?

user26481: It didn't goto zero. You can look at alternate sources https://core.jochen-hoenicke.de/queue/#2d . What happened most probably is that blockchain.info's node went down/rebooted momentarily.

93: <p>What caused the huge drop of the mempool from 60 MB to Less then 1 MB?</p>

<p>These transaction didn't get processed there was no 60 MB block mined at the time.</p>

<p>This occurred at 10:38 pm 29th August 2017 NZ time</p>

<p><a href="https://i.stack.imgur.com/E5c37.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/E5c37.png" alt="Mempool dropping to zero"></a></p>
 5406: <p>It looks like the node whose mempool size is used to generate this chart was rebooted. Also, this node appears to be running an old version of Core or another node software, because recent versions of Core persist the mempool across restarts.</p>

<p>Also see: 
<a href="https://bitcoin.stackexchange.com/q/46152/5406">How do transactions leave the memory pool?</a></p>
 26481: <p>It didn't goto zero. You can look at alternate sources <a href="https://core.jochen-hoenicke.de/queue/#2d" rel="noreferrer">https://core.jochen-hoenicke.de/queue/#2d</a> . What happened most probably is that blockchain.info's node went down/rebooted momentarily.</p>
