Is there a general way to get difficulty from any cryptocurrency coin? - bitcoin

Is there a way to get the difficulty from any coin even if there isn't a blockchain site like http://blockchain.info/ (they have an API)? I need to access it programmatically and i want to have it from the source so ripping it from a site that already lists them all isn't an option. Im using a vps Ubuntu server so the ram and mainly the diskspace is limited hence, i cant have alot of blockchains installed on it.

Most if not all have daemons you can use. You can run the daemon on the server and make a request for it. They should all be similar to the php one.

Related

Does it make sense to run scrapy/selenium script on AWS?

I am currently scraping a super slow website. Therefore, I already bought a windows2000 virtual machine. However, this machine is using a static IP. As a result, I got banned.
Now, I am wondering if it would make sense to move my script (Scrapy, Selenium and Chrome) to AWS.
Has anybody experiences in using AWS for crawling? What is the typical price for it?
You don’t need a different machine, you need a proxy. Or even better, a smart proxy.

Liferay Cloud IDE, Multiple developpers working on same liferay server

We want to start working with liferay. But the server is too heavy and the developpers computer don't have enought RAM. We want to centralize the server instance.
In other words, we want to build a development server where all developpers can connect and directly develop in their web browser, compile, view the result and push the code to git repository.
I found some good cloud IDE like eclipse CHE and a good maven archetype for liferay projet. So i can build the projet with maven. But now i want to know if it is possible to configure Liferay like every developpers can work without troubling another. And if possible, How ?
The developpers can share the same database and can use different port. Maybe, the server can generate tempory URL like some online cloud editor.
I found this post Liferay With Multiple Server Instances, but i don't think is the best way because he create one server per project. I think is too heavy.
If necessary, We have kubernetes in our IS.
Liferay's tomcat bundle, by default, is configured to take a maximum of 2.5G for the process, but it can run with far less - the default only recently was bumped up, because many people never change the default and then wonder why production systems run out of memory. For 1 concurrent user (the sole developer) on a machine, I guess that the previous default of 1G heap space is enough. Are you saying that that's too much for your developers' machines?
Having many developers on a shared server poses one problem: Yes, you may deploy different code from different machines, but: How about setting a breakpoint? Can you connect with multiple debuggers? If something fails, how do you know whos recent deployment caused the failure?
Sharing a server is an integration technique, not a development technique. If your developers don't have enough memory available for running their own Liferay server next to their IDE, it's a lot cheaper to upgrade their machines than to slow them down when everybody is accessing the same server and they can't properly debug. You pay the memory once, but your waiting developers by the hour.
Is it possible to share one server? Sure it is.
Is it possible to share one server without troubling each other? I doubt.
When you say: You think it's too heavy: What are you basing that assumption on? What does the actual developer machine look like and what keeps you from investing in the extra memory?
It's trivial to share some infrastructure - i.e. have all of them connect to the same database server (and give everyone their own schema). But just the extra effort and setup might require you to pay the developers by the hour as much as you'd otherwise pay for a couple of memory chips.
And yet another option is: Run Liferay on a remote server, but keep 1 instance per developer. This way you don't need the local memory, but can have the memory in the cloud. Calculate if you pay more for remote cloud machines than for local memory - that decision is up to you.

cPanel : Running an application

I am trying to build a middleware application ( you know...retrive data from a webservice and store to db in cPAnel and send the data to the webservice hosted from here)
Is it possible to run an application in cPanel?
If it is possible what is the prefferedlanguage for this purpose and
why?
If I am trying to run an application which has to update this fetch
hourly automatically form code.is it possible.means i want this
application to be in running state for an indefinite time.Is it
possible?
My thoughts are:
1. cPanel is not a jumping off point for applications. It is simply a shared hosting management console. It gives you the ability to do some management. You can fire off applications by making a cronjob.
Generally you have two choices, you can use shell scripting or PHP invoked from a shell.
Now this narrows it down further. PHP is configured to have a maximum execution time to stop people hogging the processors.
If you are going to write some proper middleware, I'd suggest that you either get yourself an Amazon, Jelastic or some other cloud hosting provider. You will get the ability to deploy a real application, on a full operating system - rather than "hacking" a solution.
cPanel based installs are really for those people who just want to put a website, whack up a blog, or do some low bandwidth hosting. Running something constantly is going to have you violate the terms of service on these accounts very quickly.

Sandbox a java applet

I heard that minecraft server is very leaky, can consume a lot of resources very quickly. People say to use a virtual machine, all well and good. I'm making an application to automate server setup, and I'd like my whole application (including minecraft) to run in an ultra basic auto setup vm (or something similar). I've heard of mineos, but I'm not sure if that can be set up very quickly. The vm will be so basic it won't even have a ui. I'm using a Mac, not planning to distribute the server WITH the application but have it download from the minecraft server, not modified.
I want it to be like a one-click-done solution for the end user, they don't have to worry about minecraft server gobbling up resources because it's be in a controllable virtual machine.
Distrubuting minecraft server (Notch's property) could be an issue, but if anyone knows about that if be happy to hear.
If you intend for a server to be fully configured and only for your user to only have to download and 'open' it, what you're seeking is known as an 'appliance'. Virtualbox supports the open-standard of such appliances, allowing a single file to be distributed and it contains all the virtualized hardware info as well as the OS/filesystem. A number of other formats exist, such as Turnkey.
In all likelihood, I would find MineOS CRUX to be perfectly suited for this sort of one-click-done, since the OS was designed for pretty much exactly what you're trying to do...only without the configure-the-hardware-for-the-user (it uses an ISO and an installer, the process you would automate for the end-user).
That said, this distribution has never at any point packaged Minecraft files, as clearly stated: "this Linux distro does not contain ANY Minecraft files. The scripts are, however, designed to download/update files directly from the source: http://minecraft.net"
Hope this answers all the concerns, despite being an old thread.

Server Setup: Based on Apache and Tomcat needs

I'm trying to setup a server based on our needs for a new website. Basically, I need to build a website based on social engine, and according to the platform's requirements (found here: http://www.socialengine.net/support/documentation/article?q=152&question=SocialEngine-Requirements) it requires the webserver to be Apache based.
Now my issue comes with the addition of a web application that needs to be included in the site. The web application requires the server to be capable of Asynchronous Request Processing, and is currently only supported by Tomcat or GlassFish.
I found a couple tutorials such as this one http://www.serverwatch.com/tutorials/article.php/2203891/Integrating-Tomcat-with-Apache.htm that explain how to "integrate" Tomcat into Apache. Would a server running Tomcat alone be able to handle the applet needs as well as serve the Apache (assuming HTTP) needs from the Social Engine platform? Are there any hosting providers any of you would reccomend?
Although I've done alot of front end stuff before, this is the first time i have to deal with any of the back end details, so my knowledge of server side functionality is really garbage. Please let me know if I'm not asking the right questions.
Thanks
You wouldn't really be able to use Tomcat for both apps, since the other one needs PHP. It's pretty common to have both Tomcat and Apache running on the same server. You might want to look up more recent documentation on mixing them, even this but definitely have a look at mod_proxy_ajp.
What's the other application? It's a little tricky to set up Asynchronous Request Processing if you are new to server apps, but there is also a lot of documentation, so if you're game, you can probably figure it out OK. You might also want to see if that app would work with node.js (hosting info here)
If you want to set it all up yourself, you could get a virtual private server from Rackspace Cloud or similar host or get a shared host that has the required apps already set up, which would limit your ability to customize the environment and may require 2 hosting plans, but would be easier to set up. It also somewhat depends on if both apps need to be on the same machine for any reason and/or on the same domain.
A regular LAMP stack will run SE4 just fine, however, you will need to do some tuning to get the page loads under 3 seconds. You will want to remove any Apache modules that you aren't using with a2dismod. For instance, if you're not using any Ruby on the site, a2dismod ruby. This will help get memory usage under control. APC is a must.
For a much more in depth read on tuning php/apache, please read this: Performance tuning on Apache, PHP, MySQL, WordPress v1.1 – Updated