Does Bitcoin Core have wallets creation amount limitation

Question

We are developing a community where the Bitcoin Core is used as payment processor. So we create wallet for each user (which occasionally creates new .dat files), then we generate addresses and send payments to user's wallet. As we may have to many wallets, more then 100K or 1M I have been warned that the Bitcoin Server may crash due to too many files created.

So my questions are: Does Bitcoin Core have problem with too many wallets? Which is the recommended limit? May be the limitation is only in container Linux server CPU abilities? So bigger CPU may handle more wallets and not to crash?

Thank you for your support in advance.

Answer 1

The limit is entirely dependent on the RAM of your server and the size of the wallets. Firstly, the operating system will have limits on how many files can be open. This limit may be dependent on the amount of RAM in the system. Then there is the actually the amount of RAM available for containing open wallets themselves.

Wallets are loaded entirely into memory. All keys, transactions, metadata, etc. that exists in a wallet file will be held in memory while the wallet is open. At the same time, the file will also remain open so that changes to the in-memory state are reflected to the file on disk. As such, you will be limited by the amount of RAM available.

Bitcoin Core itself imposes no limits on the number of wallets open nor on the size of the wallets. You will not get any warnings from Core if you have too many open or have wallets that are too large - the operating system may force kill the process.