All, due to all the BCT.org issues this weekend I created a forums site at nxt.freeforums.net in hopes of continuity. IMO just 1 thread in alt is just not ideal. A separate forums site would really allow much more discourse about NXT by allowing multiple threads on different issues. Please sign up and we can start new threads over there. I have cleared this with CfB and most likely he or his designate will take over. I have already created a few different boards there for breaking up the discussion.
I can't access nxt.freeforums.net because it seems to ban Tor exit nodes. Why did you pick that forum host? How about http://nabble.com , lots of open source mailing lists and forums are there? |
|
|
|
is it necessary to just attempt to open the 7874 before the 7875? Yes, until I find how to autolaunch a servlet. Try adding load-on-startup=1 parameter, worked for me: <servlet>
<servlet-name>Nxt</servlet-name>
<servlet-class>Nxt</servlet-class>
<load-on-startup>1</load-on-startup>
<init-param>
<param-name>myAddress</param-name>
<param-value></param-value>
</init-param>
</servlet>
|
|
|
|
Edit: Actually all these *.nxt files r wirtten and read using Java Serialization API. Is it a good approach? It is really bad. It's better to use some java embedded sql engine like H2 or HSQLDB. Well, in the long term yes, of course, but right now seems everything is kept in memory and those *.nxt files just function as persistent storage between restarts. If you don't need to run SQL queries, deal with database transactions, ORM, JDBC, think how much it simplifies things. I am sure BCNext realizes it is not a scalable solution as the blockchain grows, but I am impressed how fast he can add functionality by keeping things simple in the beginning. |
|
|
|
Nxt uses direct memory buffers for networking part. If Nxt requests such a buffer JVM takes space reserved for heap and gives it to the buffer. After the buffer is no longer needed JVM "forgets" its reference but reserved memory is not claimed immediately, it depends on OS internal mechanisms. After a while this chunk of RAM can be used again, but if the flow of requests is very intensive, then JVM simply runs out of free memory. That's why we can see a lot of "Not enough memory/heap" errors and NullPointerExceptions.
Could Java gurus confirm this, please?
I am not so sure, it is not common to have NullPointerException as a symptom of not enough memory. Normally you get OutOfMemoryError which should be logged as such... unless it happens in some background thread and that thread just dies silently. The code, at least as distributed, doesn't print much debugging info, so maybe the OutOfMemoryErrors are indeed swallowed and ignored. |
|
|
|
It's not related to the OS, it's just Javas crappy memory handler.
edit:
With Build 17 Chrome has 80% CPU usage on Core i3 when the client is open on localhost.
The high CPU load after running the browser for some time is a separate problem, but it has nothing to do with java, this is a javascript issue in the client (i.e. in the browser). I also have to restart firefox on my desktop because it gets slower and slower after a while, even though I run the Nxt java process on a separate machine. So don't blame java for this at least. |
|
|
|
Post here what part (mining algo, crypto, peer connection, etc.) u need and I'll post it here after I get it from BCNext.
The part that seems to need most work at the moment is the networking and the loading of the block chain, which is still not stable, isn't it? It is also probably not Nxt specific, so disclosing it is not likely to help someone clone Nxt. I could try to help debugging it. |
|
|
|
Edit: This is now hosted at https://bitbucket.org/JeanLucPicard/vanityI decided to clean up and improve the vanity account number generator mentioned before: https://bitcointalk.org/index.php?topic=303898.msg3691750#msg3691750This is the updated version: Source code: https://dl.dropboxusercontent.com/s/gtq6vm1f346oqyy/Vanity.javaCompiled jar file: https://dl.dropboxusercontent.com/s/f9xdycfu3w73q09/Vanity.jarsha256sums: 4d2e1e182637c564f95fea1e8864fa2364769f42e28ed4135b99b5514a7f4f1f Vanity.jar 3d98075c9e51c99b78f0794fc402dfbfd984f609308b53a234d1efb0f024737f Vanity.java To run it: In addition to searching for accounts starting with a given prefix, now it can also search for accounts containing sequences of repeating digits. So there are three modes of operation. Without any parameters, it will start from a random 16-character secret phrase and keep appending characters to it trying to find vanity-looking accounts: $ java -jar Vanity.jar
Using a randomly generated secret prefix: )trT-&Ubyp+d]p`k
Generating vanity accounts...
)trT-&Ubyp+d]p`kE$[ gives account number 3333335333097075555
)trT-&Ubyp+d]p`k!)o4 gives account number 8888377001144420555
)trT-&Ubyp+d]p`k!%Bw gives account number 10713333338888888154
With a single parameter, it will use this as the secret prefix instead of a randomly generated one. $ java -jar Vanity.jar my_secret_password
WARNING: For a given secret prefix, the passwords this program generates
are always the same. Therefore, using a strong secret prefix is crucial.
Anyone who can guess your secret prefix can use this program to also
discover your password. You have been warned.
Using a user-supplied secret prefix: my_secret_password
Generating vanity accounts...
my_secret_password861 gives account number 9999679005505533333
my_secret_password!(k^ gives account number 2111114455001119991
my_secret_password"!uE gives account number 13220066661444888887
With two parameters, it defaults to the original behavior, i.e. looking for shortest account number using the first parameter as secret prefix and the second as the account prefix. $ java -jar Vanity.jar my_secret_password 888
WARNING: For a given secret prefix, the passwords this program generates
are always the same. Therefore, using a strong secret prefix is crucial.
Anyone who can guess your secret prefix can use this program to also
discover your password. You have been warned.
Using a user-supplied secret prefix: my_secret_password
Looking for the shortest account numbers beginning with 888
Generating vanity accounts...
my_secret_password#$ gives account number 8880281789351433347
my_secret_password^7 gives account number 888082872862915443
my_secret_passwordB`O gives account number 88888386812508853
To repeat the above warning once again: For a given user-supplied secret prefix, the sequence of generated account numbers is always the same. This is in order to keep the number of characters appended to the secret prefix small. So it is extremely important that you pick up a strong secret prefix. Anybody who can guess your secret prefix can just run this program with it to arrive at your full secret phrase. This obviously doesn't apply when you let the program generate the secret phrase randomly (i.e., running it without any parameters). |
|
|
|
He promised to release the source code in two months, correct? Could you convince him to do that now instead?
I managed to convince him to reveal some pieces of code. This won't allow to clone Nxt but still help to review it and help to fix bugs. So, what do we need? I'll create a dedicated thead. He should still think about setting up a dead man switch, e.g. using http://www.deadmansswitch.net/ , and give you an encrypted copy of the complete code. Then, if he suddenly disappears (or the KGB finally gets to him...), you will receive an email with the encryption key. |
|
|
|
I connected to remote host with PuTTy and did this [root@Nxt ~]# ssh -L localhost:7885:localhost:7875 192.161.175.142 The authenticity of host '192.161.175.142 (192.161.175.142)' can't be established. RSA key fingerprint is xxxxxxxx Are you sure you want to continue connecting (yes/no)? y Please type 'yes' or 'no': yes Warning: Permanently added '192.161.175.142' (RSA) to the list of known hosts. root@192.161.175.142's password: Last login: Mon Nov 25 17:40:31 2013 from nnnnnnnn [root@Nxt ~]# Try connecting to http://localhost:7885/ but unsuccessful. What did I do wrong? Edit: local machine is windows Wait, you don't run ssh on the remote machine... you run ssh on your local machine. Looks like you just connected the remote machine to itself  Since you are on windows and using PuTTY instead of ssh, use the PuTTY configuration under Connection/SSH/Tunnels... to define the ports to be forwarded. But I would need to figure it out too what exactly to enter where, it has been many years since I used PuTTY and windows... |
|
|
|
Well all I was saying that a "dev team" would be faster then just one dev alone...
This is not always true, it takes time for a new developer to get up to speed with an unfamiliar project. And a big team of developers often wastes time arguing back and forth how things should be done, while a single developer will just do it as he seems fit, and get it working. As a Java developer myself (and Nxt stakeholder), I would love to start helping with Nxt. But I understand the need to keep the source closed, so I can wait. Finally, there is a innovative new coin done in Java, and not just another BTC clone. |
|
|
|
I have finally up & running my VPS client @ http://94.102.63.115:7875/Does that mean that other users can connect there with their accounts? If so I would be glad to host them (and a good opportunity to test if everything is ok)! They could connect, but please be aware passwords are submitted in clear text - better use accounts holding only small amounts. Here is a security tip for those running Nxt on a remote server: The Nxt server uses plain http, not https. So if you a running a VPS server at http://my-server.example.com:7875, every time you unlock your account there is a risk that the password will be captured in transit. There is another annoyance in such a setup: since you are not running on localhost, the Nxt interface disables access to certain features, e.g. you cannot remove peers from the blacklist / active list by clicking on the trash icon. But as long as you have ssh access to the remote server, there is a simple solution. Just use ssh tunneling: ssh -L localhost:7885:localhost:7875 my-server.example.com The above command will establish an ssh tunnel between your machine (localhost) and the remove server where Nxt is running, my-server.example.com, from port 7885 on localhost to port 7875 on the remote host. Then, instead of going to http://my-server.example.com:7875 , open http://localhost:7885 , and you will be connected to the remote Nxt instance. Except, your connection will be encrypted so nobody can listen to it. And, from the point of view of the remote Nxt process, your connection is coming from localhost, so editing the peers lists will be enabled. Once you make sure it is working, the next time you invoke ssh you can just put it in the background, and also use the -N flag so that it does not open a terminal connection (unless you need it): ssh -L localhost:7885:localhost:7875 -N my-server.example.com & (Note: I use port 7885 on localhost, in case 7875 is already used by a local Nxt instance. But any available port can be used instead.) Obviously, in your case you can securely access your VPS server over this ssh tunnel, but other users are still at risk - and you can't give everyone ssh access. |
|
|
|
Since many Windows users are not used to running command line software, we should make the installation a bit easier for them. I decided to package Nxt using the Launch4j wrapper, http://launch4j.sourceforge.net/ which creates a single windows executable out of a jar file. To run it, the user just double clicks the downloaded exe file. If there is no JRE installed, launch4j will automatically open a browser to http://java.com , allowing the user to download and install java. Nxt runs in a console window, to stop it just close the window or click Ctrl-C inside it. All the *.nxt files are created in the directory where nxt.exe was saved, so to avoid cluttering your Desktop or Downloads folder, create an empty Nxt folder and put nxt.exe inside it before clicking on it. Here is version 0.2.7: https://dl.dropboxusercontent.com/s/2fz4pc87dvrxlxr/nxt.exesha256sum: 519fa41c5517d8e743a93da97a38788b7aebed93d6be9b612da163646e67d4fe I couldn't find a way to make Launch4j automatically start a browser to http://localhost:7875 after launching the java process, so for now it has to be done separately by the user. Updated the windows package to 0.2.7 too. If anyone tried it, let me know how well it works - I only tested it on Windows XP inside VirtualBox, this is the only windows I have... |
|
|
|
Shouldn't really be helping a competitor I guess, but I'm a nice guy! I've read a lot of posts where the culprit for problems has been time. I would seriously suggest implementing support of this http://www.ntp.org/ into your client and use it to syncronize an internal clock withing the client on start to UTC. You can get a Java API for it and do it all behind the scenes without needing users to piss about with clocks. You're welcome I disagree. A workaround like this will only lead to problems later in development. Do you ever show this "internal true time" to the user, e.g. in transaction timestamps? Or do you always compensate for the difference in user-visible fields? This will complicate the code and create obscure bugs, and right now developer's time is our most precious resource. Really, at this early stage users who can't get their computer clocks in sync should not be running Nxt nodes. And development efforts are better directed towards making sure the network is resilient to some node clocks being out of sync - either ignoring, or somehow accommodating those nodes without disrupting all others. |
|
|
|
Can any one help me on how to run nxt with ubuntu?I am still having problems with sending coins from my local client so I would like to try if it works when I run it on ubuntu Thanks in advanced! Hint: If you want to install Oracle Java (instead of the default OpenJDK) on Ubuntu, the easiest way is to use the webupd8.org repository. This way you will also get updates automatically, and the java installation is less likely to conflict with the OpenJDK or other previous installs. Follow the instructions here: http://www.webupd8.org/2012/01/install-oracle-java-jdk-7-in-ubuntu-via.html |
|
|
|
Since many Windows users are not used to running command line software, we should make the installation a bit easier for them. I decided to package Nxt using the Launch4j wrapper, http://launch4j.sourceforge.net/ which creates a single windows executable out of a jar file. To run it, the user just double clicks the downloaded exe file. If there is no JRE installed, launch4j will automatically open a browser to http://java.com , allowing the user to download and install java. Nxt runs in a console window, to stop it just close the window or click Ctrl-C inside it. All the *.nxt files are created in the directory where nxt.exe was saved, so to avoid cluttering your Desktop or Downloads folder, create an empty Nxt folder and put nxt.exe inside it before clicking on it. Here is version 0.2.9: https://dl.dropboxusercontent.com/s/2fz4pc87dvrxlxr/nxt.exesha256sum: 883b4e592f8b5aee45294ab26e6c90439d93e482867ab0213fb95dd66df76895 I couldn't find a way to make Launch4j automatically start a browser to http://localhost:7875 after launching the java process, so for now it has to be done separately by the user. Edit: Updated to version 0.2.9. |
|
|
|
Guys, only a few accounts r mining. More of us mining = higher security of Nxt!
If I unlock a new account with 0 balance, does that count as mining node, or should I transfer a few Nxt to it first? How about if I keep the same account unlocked (with positive balance) on more than one machine? Is that even possible? |
|
|
|
Why does the time in transactions and blocks list say 24 Dec 2013?? We are still in November, right? Or is it a bug related to the java numbering of months...
BCNext confirmed that server part contains calendar.set(Calendar.MONTH, Calendar.NOVEMBER); Client part: Date.UTC(2013, 11, 24, 12, 0, 0, 0) Weird... This is where the problem is, must be Date.UTC(2013, 10, 24, 12, 0, 0, 0). Java numbers the months starting from January=0, so November is month number 10... very annoying but I guess too late to change in the JDK. But if the server side code is fine, fixing just the client should be simple. http://docs.oracle.com/javase/7/docs/api/java/util/Date.html#UTC(int,%20int,%20int,%20int,%20int,%20int) |
|
|
|
|
Why does the time in transactions and blocks list say 24 Dec 2013?? We are still in November, right? Or is it a bug related to the java numbering of months...
|
|
|
|
You're not blacklisted on my client, I'm connected to both nxt and fluke.
So maybe it has something to do with my local network setup, if it works for outside nodes then it's good. I run only one externally visible node, nxt and fluke actually resolve to the same IP. |
|
|
|
|
Show Posts
