Running on a port other than 8333

I’ve been working on adding -port= / -rpcport= command line / config file options to bitcoin. The idea is to let you run multiple copies of bitcoind on one machine; I need this because I’m planning on having at least two Bitcoin-related web services (the Bitcoin Faucet and a service to be named later), I want them to have completely separate wallets, but I don’t want to rent multiple servers to host them.

Usage looks like this:

$ ./bitcoind getbalance  # The TEST network Faucet bitcoind
40616.66159265000
$ ./bitcoind -datadir=/home/bitcoin/.bitcoinTEST2 getbalance
1000.000000000000
$ cat /home/bitcoin/.bitcoinTEST2/bitcoin.conf
rpcpassword=.....
port=18666
rpcport=18665

Satoshi pointed out that allowing bitcoin/bitcoind to run on a non-standard port could be dangerous, because if misconfigured two bitcoins might both open and write to the same database. To prevent that, the /db.log file is used as a lock so only one bitcoin can access the same datadir at a time (uses boost::interprocess::file_lock, which is purported to be cross-platform and well-behaved, even if bitcoin crashes).

Issues that came up as I was doing this:

I left a call to wxSingleInstanceChecker in the Windows GUI code, so no multiple-gui-bitcoins-listening-on-different-ports on Windows. I don’t do Windows…

I didn’t bother making the error handling graceful if you point two bitcoins at the same datadir (you get a runtime exception “Cannot lock db.log, is bitcoin already running?”).

Patches are at http://pastebin.com/2e4hfXSS; I’ve only tested on Linux so far, anybody willing to try this on Windows?

Quote from: gavinandresen on July 27, 2010, 5:08:17 AM UTC

I’ve been working on adding -port= / -rpcport= command line / config file options to bitcoin

Nice. In addition it would be good to have an -ip= option for what address to bind the port. (rpcport binds to 127.0.0.1 but currently port binds to 0.0.0.0 which is all IP addresses on the machine. On my multi-homed system I’d like to bind bitcoin to the external address different from the bitcoin(s) that binds to the internal address(es).)

Do you have an updated version of this patch for SVN revision 125? Also, does Bitcoin open the BerkeleyDB as exclusive, precluding the need for a file lock?It does not — did my own tests.

Quote from: lachesis on August 10, 2010, 6:24:55 AM UTC

Do you have an updated version of this patch for SVN revision 125? Also, does Bitcoin open the BerkeleyDB as exclusive, precluding the need for a file lock?It does not — did my own tests.

It does open with DB_PRIVATE.

http://www.oracle.com/technology/documentation/berkeley-db/db/api_reference/C/envopen.html

Quote from: lachesis on August 10, 2010, 6:24:55 AM UTC

Also, does Bitcoin open the BerkeleyDB as exclusive, precluding the need for a file lock?It does not — did my own tests.

Is there a way to open BerkeleyDB exclusive?

DB_PRIVATE is the worst of both worlds.  DB_PRIVATE is not exclusive, but it does make it get screwed up if another process tries to access it at the same time.

I’ve dropped the DB_PRIVATE flag in rev 153.

Quote from: satoshi on September 12, 2010, 5:40:20 PM UTC

Is there a way to open BerkeleyDB exclusive?

What is your intended goal?

If it is to prevent two bitcoin clients from actively using the same database, you’ll need to employ application-level protection. Crude methods of this include a lockfile or “lock” database entry.

If the intention is to prevent all other access, I’d suggest giving up on that goal 😊 It is highly useful to permit db4 tools to access db4 databases:Code:db46_archive db46_deadlock db46_load db46_stat db46_checkpoint db46_dump db46_printlog db46_upgrade db46_codegen db46_hotbackup db46_recover db46_verify and just as useful to permit read-only accesses by tools such as gavin’s bitcointools.

Quote from: gavinandresen on July 27, 2010, 2:08:17 PM UTC

I’ve been working on adding -port= / -rpcport= command line / config file options to bitcoin. The idea is to let you run multiple copies of bitcoind on one machine; I need this because I’m planning on having at least two Bitcoin-related web services (the Bitcoin Faucet and a service to be named later), I want them to have completely separate wallets, but I don’t want to rent multiple servers to host them.

Same here. I have managed to create 2 wallets and two instances of a bitcoin.conf.

both have a different rcport specified in the config (8332 and 8333)

I can start either one of them and it works fine, the web sites using the wallet can connect.

However… If I start the second bitcoin instance (I’m on windows) the second process grows to about 6 Mb and then just dies… So each of them wallets runs just fine alone but not together.

Is there any way I can debug to see what happened? I tried switching on options in the config (like noirc and the connect only to…) but it does not seem to make a difference.

Kind regards,

MoneyTree

http://doubletrouble.bitcoinbet.com/

Quote from: MoneyTree on January 19, 2011, 11:41:59 PM UTC

both have a different rcport specified in the config (8332 and 8333)

8333 is the hardcoded P2P port.