<p>So far, no released versions of Bitcoin Core exist that store the mempool on disk. That's why it's called the <strong>mem</strong>pool; it's a pool of unconfirmed transactions kept in memory.</p>

<p>Version 0.14 is expected to introduce automatic dumping of the mempool to disk at shutdown.</p>

CC BY-SA 4.0
2022-11-07T04:14:53.847Z
"Version 0.14 is expected to introduce automatic dumping of the mempool to disk at shutdown." This was indeed done: https://github.com/bitcoin/bitcoin/blob/master/doc/release-notes/release-notes-0.14.0.md#retaining-the-mempool-across-restarts
Larry Ruane
CC BY-SA 3.0
2016-11-28T03:33:45.210Z
2016-11-28T03:33:45.210Z
Pieter Wuille
<p>I'm using bitcoin core version 0.12.1 (To say precisely, I'm using addrindex patched bitcoin core by btcdrak)</p>

<p>I expected that mempool was maintained after restart bitcoind but that was deleted.</p>

<p>As far as I know that mempool is stored in chainstate/* directory as LevelDB data. 
I read this article. <a href="https://bitcoin.stackexchange.com/questions/11104/what-is-the-database-for">What is the database for?</a></p>

<p>Can you describe this is why and how can I avoid it. Sometimes, I have to restart my bitcoind for some reasons (like system maintanance). In that time I want to maintain the mempool data.
Getting mempool data from peers..? takes a long time.</p>

<p>getmempoolinfo before bitcoind restart</p>

<pre><code>$ curl --user 'xxx:yyy' --data-binary '{"jsonrpc":"1.0","id":"curltext","method":"getmempoolinfo","params":[]}' -H 'content-type:text/plain;' http://127.0.0.1:8332
{"result":{"size":15350,"bytes":120107104,"usage":258574880,"maxmempool":300000000,"mempoolminfee":0.00000000},"error":null,"id":"curltext"}
</code></pre>

<p>getmempoolinfo after bitcoind restart</p>

<pre><code>$ curl --user 'xxx:yyy' --data-binary '{"jsonrpc":"1.0","id":"curltext","method":"getmempoolinfo","params":[]}' -H 'content-type:text/plain;' http://127.0.0.1:8332
{"result":{"size":0,"bytes":0,"usage":0,"maxmempool":300000000,"mempoolminfee":0.00000000},"error":null,"id":"curltext"}
</code></pre>

<bitcoind><bitcoin-core><mempool>
Why is mempool deleted when restart bitcoind and how to keep it?
zono
# Why is mempool deleted when restart bitcoind and how to keep it?

(Asked by: username_0 on 2016-11-28)

I'm using bitcoin core version 0.12.1 (To say precisely, I'm using addrindex patched bitcoin core by btcdrak)

I expected that mempool was maintained after restart bitcoind but that was deleted.

As far as I know that mempool is stored in chainstate/\* directory as LevelDB data.
I read this article. [What is the database for?](https://bitcoin.stackexchange.com/questions/11104/what-is-the-database-for)

Can you describe this is why and how can I avoid it. Sometimes, I have to restart my bitcoind for some reasons (like system maintanance). In that time I want to maintain the mempool data.
Getting mempool data from peers..? takes a long time.

getmempoolinfo before bitcoind restart

```
$ curl --user 'xxx:yyy' --data-binary '{"jsonrpc":"1.0","id":"curltext","method":"getmempoolinfo","params":[]}' -H 'content-type:text/plain;' http://127.0.0.1:8332
{"result":{"size":15350,"bytes":120107104,"usage":258574880,"maxmempool":300000000,"mempoolminfee":0.00000000},"error":null,"id":"curltext"}

```

getmempoolinfo after bitcoind restart

```
$ curl --user 'xxx:yyy' --data-binary '{"jsonrpc":"1.0","id":"curltext","method":"getmempoolinfo","params":[]}' -H 'content-type:text/plain;' http://127.0.0.1:8332
{"result":{"size":0,"bytes":0,"usage":0,"maxmempool":300000000,"mempoolminfee":0.00000000},"error":null,"id":"curltext"}

```

**Tags:** bitcoind, bitcoin-core, mempool


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## 1 answers

### Answer by username_1 on 2016-11-28. Score: 5 | Accepted answer

So far, no released versions of Bitcoin Core exist that store the mempool on disk. That's why it's called the **mem**pool; it's a pool of unconfirmed transactions kept in memory.

Version 0.14 is expected to introduce automatic dumping of the mempool to disk at shutdown.

> **Comments:**
> **username_2**: "Version 0.14 is expected to introduce automatic dumping of the mempool to disk at shutdown." This was indeed done: https://github.com/bitcoin/bitcoin/blob/master/doc/release-notes/release-notes-0.14.0.md#retaining-the-mempool-across-restarts  

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