1Lstnibj3LKSUPfvo9Ss4cFJM3oWxzPFHq

Thank you for the answer. I'll look into it. I think it would be useful to create RPC API command to return info about such status. For example "getforkstatus 6" could return true if longest chain is longer or equal than next longest chain by at least 6 block. Additionally some --forknotify command-line parameter could notify about detecting blockchain fork...

Is there any way to detect blockchain fork using bitcoind and RPC? I would like to suspend accepting incoming transactions during blockchain forks longer than or close to my level of required confirmations (i.e. 6). AFAIK client has to track all branches so this information is available in it. I think it could be important failsafe measure especially in light of ongoing discussion about replacing transactions with new ones with higher fee.

On OS X wallet.dat is usually located in ~/Library/Application Support/Bitcoin/

Use Shift-Cmd-G in Finder and paste above path to get there.

Anyone who knows your login and password and is in rpcallow range, can control your client remotely. It is as simple as that. I would not advise to allow anyone besides 127.0.0.1 to control your client unless you really know what your doing. If you have to use such config, at least encrypt your wallet.

It is not safe to rely on concept of "sending address" in bitcoin in general. Look at this thread.

I've heard about bitcurex - polish BTC exchange. They had major performance problems caused by too big wallet (>700MB). They were using bitcoind client.

Here you can find some code in JS.

And, as a bonus, the prediction works for any other currency!

AFAIK there is no such thing as binary map of database blockchain. Every client uses it's own format to store blockchain (levelDB for example).

I get it. Thank you.

I think it will be fixed soon: https://github.com/bitcoin/bitcoin/issues/1522.

I think it's a bug. Try right-clicking on the icon and choosing "Show all windows".

What was your idea and why you think it is wrong? I'm asking, because I'm working on accepting coins myself.

There are no users in bitcoin - only addressees and I'm not sure that all double spend attempts are malicious. Isn't it possible to attempt double spend during blockchain fork under "normal usage" - not willingly?

I've read some horror stories about large, unusable wallets (eg. from bitcurex - polish BTC exchange - 700 MB+ wallet). I presume the main problem is automatically generated change addresses. Do you think following procedure would help to clean such wallet?

1. Create brand new wallet on another machine.
2. Transfer all coins from old wallet to new one.
3. Dumpprivkeys but only for adressess "publicly" available for each customer.
4. Import addressess into new wallet.
5. Get rid of old wallet.

Any suggestions?

I think you can "vacuum" the wallet once in a while:

1. Create brand new wallet with new address.
2. Transfer all funds from old wallet to new address.
3. Export relevant private keys of addressees you need active in new wallet.
4. Archive rest of the addressess.
5. Import priv keys of relevant addressess to new wallet.

Bticoin gurus: correct me if I'm wrong.

I got similar problem: https://bitcointalk.org/index.php?topic=195816.0