MultiBit

[freemoney458]

Hi Jim,

sorry to find another small strange behaviour:

3) When changing the user language, and afterwards changing from the preferences screen to any other screen, e.g. transactions screen, the language of the elements *inside* of this screen is still in the old language.
The change of the language only takes full effect after exiting and restarting MultiBit.

BTW: I agree that right click menus are not the best way on tablets or cell phones   .

Edit: The reordering of columns by dragging the column header is cool  ! I didn't notice it. Glad you mentioned it.

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[jim618]

Hi Jim,

sorry to find another small strange behaviour:

3) When changing the user language, and afterwards changing from the preferences screen to any other screen, e.g. transactions screen, the language of the elements *inside* of this screen is still in the old language.
The change of the language only takes full effect after exiting and restarting MultiBit.

BTW: I agree that right click menus are not the best way on tablets or cell phones   .

Edit: The reordering of columns by dragging the column header is cool  ! I didn't notice it. Glad you mentioned it.

Yes, the language change (and the change of Look and Feel) can be a bit quirky but if you restart MultiBit it always get it right.
It is things being cached and then not being completely reinitialised I think but i have not pinned them all down.

[Grouver (BtcBalance)]

Regarding your question Jim.
I was curious how many connections i had since the blockchain downloading went really quick.
But since i only download the blockchain from one node it doesnt really matter i guess.

I noticed when I download the client and start it up it downloads the blockchain and light-speed.
Do you download the blockchain within the client? If yes, how does this exactly work.

[jim618]

Hi Grouver,

There are a combination of techniques used to get the initial startup time as quick as possible:
1) With bitcoinj based code only the block headers are stored in the blockchain. These are 100 bytes per block. So the 200,000+ blocks take about 20 MB. I include an up to date copy in the installer. This means you only have to catch up the blockchain since the date of the last installer.
2) When you first start MultiBit you do not have a wallet yet. Thus it can save time because it does not have to check old blocks to see if there any relevant transactions. It thus tells the bitcoind it is connected to: 'just give me the block headers, do not bother giving me the transactions'. This can download at 1000+ blocks a second on a good connection.

Once you have a wallet it currently downloads the full blocks to check the transactions. In the next few months I hope to get server side Bloom filters in (see conference presentation) which should speed up the downloads when you have wallets. It won't ever be as fast as the initial setup but should be a good bit quicker than now.

[Grouver (BtcBalance)]

Regarding Multibit Merchant.
Now businesses will only start using Bitcoin to promote there company.
I mean most companies still need to buy there products or pay there employees in euros/dollars or whatever mainstream currency.
So they need there currency instead of bitcoins.

Now Bit-pay gives you the option to withdraw euros/dollars/pounds from your account to your company bank account so you can buy in your product again.
Though, the rates are crazy and do not really attract companies to start accepting Bitcoin that are in the euro zone for instance. They need to pay bit-pay 4% of there withdraw transaction wich is crazy.

Does Multibit Merchant offer any solution(s) for this problem or does the owner of the webshop get there bitcoins and still needs to go to an exchange and trade there bitcoins for euros/dollars/pounds?

If this exchange problem gets solved Bitcoin will grow huge.

[molecular]

some feedback/questions: I just checked out multibit for the first time together with my brother (recovered some coins from an old electrum wallet and we imported a private key).

• How is the change address chosen? It seems (unlike satoshi client), multibit does not generate new addresses on it's own but uses some existing address for change. Why is that? I'm assuming to solve the "wallet backup problem"?
  
  
• It seems funds are unspendable until the previous tx is in a block. Why? (this could be pretty annoying, say in case I want to send money to multiple different recipients. I would have to wait for a block in between each transaction)
  
  
• A suggestion regarding key import: I expected to be able to import a private key by pasting it into some textentry field. Instead we had to generate a file (we used key export to see what the format was). We didn't know what to use for the date and so we used todays date. As we later discovered this was a mistake, we should've entered the date the last tx on that address had taken place (we did a blockchain rescan afterwards to fix it). So the suggestion: in addition to being able to import keys from file, maybe a textbox to paste a private key could be offered. After that, a popup or something could ask for the rescan-timepoint and explain what it is about)
  
  
• A sort-of bug (likely not multibit fault, probably not even fixable from multibit source): My brother uses a window manager called "notion" (formerly "ion"). At times something gets screwed up and menus (both when selecting from main menu and also the context menu when using right-click on, for example, a transaction) appear offset to the lower right (by many pixels, somewhere completely else in the window) and menu items cannot be selected with the mouse. Once it starts occuring it keeps occuring with the same offset. A frame-resize doesn't help, but putting multibit into another frame (re-attach) does. This might not be worth investigating since it's most likely notions fault, just thought I'd let you know anyway.
  
  

Other than that our experience has been satisfying. Thanks for a great open product!

[jim618]

some feedback/questions: I just checked out multibit for the first time together with my brother (recovered some coins from an old electrum wallet and we imported a private key).

• How is the change address chosen? It seems (unlike satoshi client), multibit does not generate new addresses on it's own but uses some existing address for change. Why is that? I'm assuming to solve the "wallet backup problem"?
  
  The change address used is the address of the first transaction input consumed. This is mainly for simplicity but yes it does solve the wallet backup problem (at the cost of some anonymity).
  
  
• It seems funds are unspendable until the previous tx is in a block. Why? (this could be pretty annoying, say in case I want to send money to multiple different recipients. I would have to wait for a block in between each transaction)
  
  This is in currently because MultiBit does not have all the transactions to crosscheck that the transaction inputs are actually spendable. Talking to Jan (BitcoinSpinner) at the conference he mentioned that it IS possible to spend your unconfirmed change without it causing problems to downstream transactions so I plan to look into doing this.
  The reason it is in there is that I don't want transaction inputs that are unconfirmed to "percolate" through to chained transactions. In that situation you can have a chain of unconfirmed transactions all waiting on the very first. (If the first transaction was dust you could have a whole chain waiting for a LONG time and it creates a very poor user experience). Bitcoinspinner has access to all the transactions in a db I think so the situation is not quite the same so I need to test it out thoroughly.
  
  
• A suggestion regarding key import: I expected to be able to import a private key by pasting it into some textentry field. Instead we had to generate a file (we used key export to see what the format was). We didn't know what to use for the date and so we used todays date. As we later discovered this was a mistake, we should've entered the date the last tx on that address had taken place (we did a blockchain rescan afterwards to fix it). So the suggestion: in addition to being able to import keys from file, maybe a textbox to paste a private key could be offered. After that, a popup or something could ask for the rescan-timepoint and explain what it is about)
  
  The MultiBit key export/ import is designed primarily for backing up the MultiBit wallets and giving people the actual key values. I agree it would need more work before it was a general purpose key import tool.
  The main limitation is that MultiBit (currently) needs to go back and redownload and replay all the blocks from the key's "birth". It does not store all the transactions, only the ones for EXISTING wallet keys. When I do an import I need to know the age of the key. For keys coming from a MultiBit wallet I know the age of the private key and hence can write it out with the key data. (That is why it is a file and not a text box).
  
  An example of this: Piuk (blockchain.info) wrote some import code for MultiBit for his encrypted wallet backups he mails out when you do a spend on blockchain.info. Unfortunately he does not keep the age of the key so when I import one of his wallet backups I have to go right back to the genesis block and reload all the blocks. This is incredibly slow. If it  "gets you out of an emergency" it is acceptable but for general use it is not really quick enough.
  
  
  
• A sort-of bug (likely not multibit fault, probably not even fixable from multibit source): My brother uses a window manager called "notion" (formerly "ion"). At times something gets screwed up and menus (both when selecting from main menu and also the context menu when using right-click on, for example, a transaction) appear offset to the lower right (by many pixels, somewhere completely else in the window) and menu items cannot be selected with the mouse. Once it starts occuring it keeps occuring with the same offset. A frame-resize doesn't help, but putting multibit into another frame (re-attach) does. This might not be worth investigating since it's most likely notions fault, just thought I'd let you know anyway.
  I am not sure I can do much about this one.
  

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Other than that our experience has been satisfying. Thanks for a great open product!

Comments inline in blue.

Cheers!

[garyrowe]

Does Multibit Merchant offer any solution(s) for this problem or does the owner of the webshop get there bitcoins and still needs to go to an exchange and trade there bitcoins for euros/dollars/pounds?

(I'm the lead developer for MultiBit Merchant)

As part of my October of Bitcoin I'll be pushing MultiBit Merchant to a minimum viable product (MVP). This means that I have to strip out as much extraneous work as possible to hit that tight deadline. The MVP is unlikely to have automated fiat exchange in place, although prices will be quoted in real time from MtGox in a range of local currencies.

However, I am also involved with the XChange project and as part of that there is a push to introduce a Deposit/Withdraw API in addition to the trading API. Using XChange it should be possible to take bitcoins, deposit them onto the exchange offering the best deal at your market depth (arbitrage) and perform a trade to fiat. That fiat can then be withdrawn to your selected account using the exchange's provided mechanisms.

XChange is a Java library, but because it runs on the JVM (now known as the mlvm) it is possible for it to be accessed by any other language running on the technology (think Clojure, Jython, JRuby etc). In time, this will make it trivial for anyone using the mlvm to be able to interoperate with a wide range of exchanges.

[jim618]

I have just spent all the MultiBit donations, topped up with my own BTC, for a lifetime membership of the Bitcoin Foundation.

[garyrowe]

I've joined too! I think it's an excellent initiative.

[jim618]

After a request by Matija Mazi, I have added Slovenian to the list of target languages for MultiBit.
If you would like to help him translate the 400ish MultiBit texts, please go to:

http://translate.multibit.org

Thanks.

[bitcoinspot.nl]

Great initiative this foundation, but i was browsing the site and i see that there are different classes of membership, and different costs. The site says that: "Each Membership includes one vote in its voting class. " but does one class have more weight than another class ? so if i donate 10000 bitcoins per year as a company do i have more to say in this foundation ?

i posted this question also on the official thread....

[bitcoinspot.nl]

Just a quick note,

i just send 2,5 bitcoins to become a foundation member , so i filled in my password for the transfer
and when i filled it in for the second time for approval my screen already said "bitcoins sent successfully"

Shouldn't this message come after i filled in my password for the second time ?

Greetings from holland!

[jim618]

Hi bitcoinspot.nl,

Yes the Bitcoin Foundation is a very interesting development.

I think how the classes works is that:

+ Each class of member votes for their representative in that class.
+ One membership gets one vote.

So each of the individual members vote for their "individuals" representative, the companies vote for their "company" representative etc.


When you send bitcoin you only have to type in the password once. There is a slight delay in the send dialog updating just due to the code waiting for the network to send the bitcoin.

There are the two password entry fields when you are setting up and changing the password to help avoid a typo creating a wallet with an unexpected password.

[jim618]

Thanks to Matija Mazi there is now a Slovenian translation of MultiBit. Screen shot:



This will appear in the next live version which will probably be in around a week.

Thanks!

[jim618]

I had a user this week report that her blockchain got corrupted when her computer lost power.
Previously at startup if MultiBit could not load the blockchain you would get a red "Error" on the network indicator at the bottom left of the screen.

How MultiBit works is that there is an up-to-date blockchain included in the installer. This is a file called multibit.blockchain. When you first use MultiBit it copies the multibit.blockchain into your user data area and then starts syncing the copy in the user data area. (This is so that multiple users can be running MultiBit on the same machine).

I have put in some error recovery code so that if the user's blockchain does not load, it recopies in the one from the installer. It will then have to re-sync from the date of your MultiBit installation so this might take a while but at least then the recovery is automatic.

I think this is one of those "1 in a thousand" failures so I expect most people will never encounter it.
It will appear in the next live and test releases.

[Mike Hearn]

Re: spending unconfirmed change.

Yes this is annoying and I plan to fix it in bitcoinj at some point soon.

[Tittiez]

I think this is one of those "1 in a thousand" failures so I expect most people will never encounter it.
It will appear in the next live and test releases.

You had to get the private keys out of my corrupted file when the same thing happened to me a few months ago (I think that was what happened, or something similar).

[jim618]

Hi Tittiez

Yes what you experienced was a wallet file not being written completely (due to power loss I think). To counter this bug I have about a week ago added a rolling backup of the wallets. Now when MultiBit writes out a wallet it:
1) backs up your existing wallet to a file called [wallet name]-[current datetime].wallet in the same directory
2) writes out the wallet
3) securely deletes any previous wallet backup

Also when it loads the wallet if that fails it will load the backup.
This code will be in the next live release.

This bug was in the blockchain file so it does not affect your private keys. However MultiBit cannot work without a blockchain file so it does stop the user working.


A MultiBit user still needs to manually create wallet backups, or exports of the private keys, on a separate device such as a USB drive. This is to counter the possibility of:
1) laptop theft
2) disk drive failure
3) something else

[Tittiez]

I see. Well good to know you countered the bug.