On node startup, load mempool from peers ? #25018

1. 
   mbh86 commented at 5:45 pm on April 28, 2022: none

   Let’s say I shutdown my bitcoin node for one hour, the default behaviour at the startup is to load the file mempool.dat but all transactions that were broadcasted during this outage will not appear. I tried to disable the saving and loading with persistmempool=0 but it starts with an empty mempool on startup. How can I get the full list of unconfirmed transactions on a restart?
2. 
   sipa commented at 5:50 pm on April 28, 2022: member

   There is no way to do that with the protocol currently implemented by Bitcoin Core. There is the BIP35 “mempool” message, but it is currently only available when explicitly enabling peer filtering (BIP111), because of its enormous DoS risk.
3. 
   MarcoFalke commented at 6:00 pm on April 28, 2022: member

   Maybe this is best solved outside of the P2P protocol. It shouldn’t be too hard to write a script to dump the mempool on one of your other nodes (or a centralized service, if you don’t have other nodes) and then import the dump?
4. MarcoFalke added the label Mempool on Apr 28, 2022
5. MarcoFalke added the label Questions and Help on Apr 28, 2022
6. 
   sipa commented at 6:01 pm on April 28, 2022: member

   @MarcoFalke Well, or copy the mempool.dat file.
7. MarcoFalke closed this on Apr 29, 2022

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8. 
   mbh86 commented at 8:10 am on April 29, 2022: none

   Thanks a lot @sipa @MarcoFalke.
9. DrahtBot locked this on Apr 29, 2023

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Mempool Questions and Help