Does mempool have size limit?

[BlackHatCoiner]

I haven't searched it on the code but does it? As bitcoin transactions per second increase, which also increases the median fee, it also means that more transactions are kept in the mempool. At the time I'm posting mempool has 105,916 transactions and the recommended fee is 226 satoshi per byte. (Lot of higher, comparing few days ago)

[1715425942]

1715425942

[1715425942]

1715425942

[1715425942]

1715425942

[pooya87]

mempool is the pool of transactions inside your memory so practically it is limited by your memory. there is also a default limit set at 300 MiB by bitcoin core and it appears to be editable (you can change it).

[ABCbits]

there is also a default limit set at 300 MiB by bitcoin core and it appears to be editable (you can change it).

For reference, you can edit it by modifying bitcoin.conf (AFAIK it's not created by default). I recommend using this tool https://jlopp.github.io/bitcoin-core-config-generator/ and then copy it to bitcoin.conf

Code:

# [core]
# Keep the transaction memory pool below <n> megabytes.
maxmempool=1000

On a side note, by default a transaction will be dropped within 336 hours if it's not confirmed.

[mocacinno]

you can set parameters both for the size and the maximum age of unconfirmed transactions in your mempool...

in your bitcoin.conf:
maxmempool=
in Mb, default 300 Mb

mempoolexpiry=
in Hours, default 336 hours

I don't think there's any limit other than the total memory size (+ swap), there are default values tough...

[Pmalek]

mempool is the pool of transactions inside your memory so practically it is limited by your memory. there is also a default limit set at 300 MiB by bitcoin core and it appears to be editable (you can change it).

If it depends on your RAM and is editable, what happens if you set it to your max RAM capacity? Will it result in a crash of your node with any loss of data?
Is there a warning displayed that your mempool is getting filled and the implications that can have on your memory or node?

[pooya87]

mempool is the pool of transactions inside your memory so practically it is limited by your memory. there is also a default limit set at 300 MiB by bitcoin core and it appears to be editable (you can change it).

If it depends on your RAM and is editable, what happens if you set it to your max RAM capacity? Will it result in a crash of your node with any loss of data?
Is there a warning displayed that your mempool is getting filled and the implications that can have on your memory or node?

i'm not sure. there must be some additional checks to prevent system from running out of memory in place that i can't find. all i see is the setting itself which doesn't seem to have any check for a ceiling value.
https://github.com/bitcoin/bitcoin/blob/df2129a2349b1877049f250551f49a4592e73765/src/init.cpp#L1102-L1105

[Wind_FURY]

OP, I believe it's also good to read how the mempool actually works, to have a better visualization each time you click that the send button.

You will also gain a new appreciation after broadcasting your transaction on an actual decentralized network.

[BlackHatCoiner]

OP, I believe it's also good to read how the mempool actually works, to have a better visualization each time you click that the send button.

You will also gain a new appreciation after broadcasting your transaction on an actual decentralized network.

What are you talking about? You don't make sense. I do know what is mempool and how it works. I've broadcasted lots of transactions, I just didn't know that small detail that you configure from bitcoin.conf.

As for your reply, you will gain a new appreciation after you stop spamming/replying without any useful content.

[Wind_FURY]

OP, I believe it's also good to read how the mempool actually works, to have a better visualization each time you click that the send button.

You will also gain a new appreciation after broadcasting your transaction on an actual decentralized network.

What are you talking about? You don't make sense. I do know what is mempool and how it works. I've broadcasted lots of transactions, I just didn't know that small detail that you configure from bitcoin.conf.

As for your reply, you will gain a new appreciation after you stop spamming/replying without any useful content.

No, I'm not spamming, and don't be insulted. I wasn't lecturing you. I was simply pointing out the importance of learning the basics/how things work.

Your question in OP merely made me think that you haven't fully understood/visualized that the "mempool", is actually in all nodes of the Bitcoin network, not a "single thing" in "the cloud".

I was also merely pointing out, that as our understanding grows, we gain new appreciation of how Bitcoin works.

Or, if you were checking your own node's status, then OK, I was the one confused.

[ABCbits]

Your question in OP merely made me think that you haven't fully understood/visualized that the "mempool", is actually in all nodes of the Bitcoin network, not a "single thing" in "the cloud".

Since OP mention both keyword "mempool" and "code", OP is clearly asking about mempool limitation within Bitcoin Core rather than mempool in general.
Besides, mempool isn't part of Bitcoin protocol and it's possible a node don't have mempool (you can even disable it on Bitcoin Core).

[gmaxwell]

It's going off-topic, but I also read the OP like wind-fury did-- but trusted y'all would set it all straight, and you did.