The particular situation I am looking at is a Lighttp webserver embedded in a hardware device, similar to your home network router. So you can imagine, the footprint is small in both memory availability and processing power.
The two choices offered to me for developing the web application used to configure this device is either Django or Ruby on Rails. This is a telecommuncations device and the web application will configure settings on it as well as manage contact directories and the ability make outbound and accept inbound calls to and from the device. The application will also be used to upgrade the device.
The current interface uses a Flash front-end and php backend. But they want to get rid of both Flash and PHP.
So what is the prevailing opinion out here for this situation?
So you can imagine, the footprint is small in both memory availability
and processing power.
No chance you will see that with Python or Ruby. I think you need to provide more details for us to help you out.
Your question as asked ("prevailing opinion") is off-topic for stackoverflow (no definitive answer). However, I think what you're really asking is "are there any technical obstacles or benefits to using RoR vs. Django on a device with only XYZ resources?"
We can't answer that without knowing exactly what the limitations of your device are. It could be that neither framework is suitable, or either one would be fine (the latter is more likely, if someone has 'offered' you these as choices).
You may find answers to this question helpful:
Are there benchmarks comparing the respective memory usage of django, rails and PHP frameworks?
Related
I want to create mobile apps using webRTC APIs. My basic need is one-to-one video calling capability. Should I just use an open source webRTC server like openwebrtc? I want it to handle at least 5k clients. Is there any other option to fulfill my needs?
This question is very broad (and this isn't a proper answer), and is likely to attract very opinionated answers, and is also likely to be deemed as off-topic for Stack Overflow.
Having said that, if you can provide more information, you might get some reasonable opinions.
Please provide more information about what is important to you.
As WebRTC is a peer-to-peer system, scaling isn't a major issue. You need a signalling server of some kind to do call establishment. That work is over quite quickly, and then the two parties can continue the call without needing the server any more.
I don't have experience with openwebrtc, but I have used PeerJS, and found it to be quite good. It hasn't been updated in 2 years, but it seems to do the job pretty well, and is quite lightweight.
There are some commercial offerings around, but I question the value, as they leverage heavily from the open source components, and rely on the browsers for support. They are probably worth using if you want to do many-to-many video calling, as that is when you need a video server.
WebRTC is supposed to be easy, and it has been in the browsers for several years now (notably excluding Safari and IOS). It is a difficult area, and will take some time to master.
OpenWebRTC project is a reasonable option for a basic video calling native mobile app; its signalling server is only a basic demo, all written in JavaScript. As such, it should not crash on 5K simultaneous peer video connections.
But a real-world solution might require much more than this: TURN and STUN services, backup for the moments of hardware failure, load balancing, statistics and administration interfaces. Take security seriously: you should be able to cut out a spammer or other offender, in addition to protection against hackers.
Server software is that can help you will not necessarily cost much. See also https://stackoverflow.com/a/38810518/192373.
im currently making an iphone application that will be in need of a web service. And obviously im thinking about releasing it to appstore eventually. So my question is what kind of web service should i use that is "well known " or what normally people woould choose?
It does not have to be free just that its professional. Anyone has some tips?
I have been looking into amazon web services and im trying the 12 months free trial, and i cant seem to find any tutorial of how to upload some files that will produce a json text as a GET request. If anyone have some information regarding that or a tutorial that would also be great!
If you are not happy/confident about developing server side code you could also consider using services such as Parse
https://www.parse.com
You're asking some extremely open-ended questions for which there is no single good answer.
So my question is what kind of web service should i use that is "well known " or what normally people woould choose?
There are plenty of "well known" web services to choose from. First you need to decide if you want this to run on Windows or on linux, and the answer for that question depends mostly on what you are comfortable working with and what you're used to programming on. If you're going the linux route then you further need to decide what linux distribution to use: RedHat, Ubuntu, Debian, Amazon, etc.
The answer to that question will then narrow down your choices of the actual "web service", be it IIS (Windows only), Apache, nginx, etc. And those answers will also depend on and/or help decide which programming language(s) you want to utilize: java, C#, python, ruby, perl, etc.
i cant seem to find any tutorial of how to upload some files that will produce a json text as a GET request.
The reason you can't find such a tutorial is because it's going to depend greatly upon the answers to all the above questions. If you want to implement this on Windows using IIS and C# then any tutorials are going to be specific to those choices. If you want to implement this on linux using Apache and java then any tutorials are going to be specific to those choices, and significantly different from the Windows based tutorials.
Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 9 years ago.
Improve this question
Are Ruby on Rails site usually slower than java or .net sites?
(This is assuming developers are not abusing the technology.)
A lot of Ruby sites I have seen have performance issues.
Yes, Ruby on Rails sites do have performance issues, just like any other site. And just like any other site, those performance almost always are rooted in architectural decisions, not the language or the framework.
There was a nice presentation a couple of years back by Joyent (might have been RailsConf 2007?), which showed on one slide all the servers that are running on a single instance of their Rails platform. About 40 processes. Only one of those processes was the Ruby interpreter, everything else was stuff like the DNS resolver, web server, database server, MTA, memcached, message queue, reverse proxy, load balancer, etc. Every single one of those can screw up your performance. That's a 97.5% chance that your performance problems have nothing whatsoever to do with Rails or Ruby.
There's some really nice E-Mails on the JRuby mailinglists, and also some Tweets and blog posts by people who rewrote their Java web applications in Ruby and got a 10% performance improvement.
A really good example is Twitter. Twitter is one of the biggest Ruby on Rails sites in the world. It is also one with a very unusual usage pattern that will give any framework that is designed for "normal" web applications a tough nut to crack.
Now, you might think, why did I choose Twitter of all things as an example of performance and scalabilit, when clearly it is the exact opposite that they are known for? Well, that's exactly the point: they have had a ton of scaling, performance and reliability problems. And not a single one of those had anything to do with Rails or Ruby. In fact, Rails and Ruby were pretty much the only pieces in their stack that they did not have problems with.
They had problems with unexpected growth. It doesn't matter which language or framework you use: if users are signing on faster than you can buy new servers, there is nothing you can do.
They had problems with the performance and scalability of MySQL. Again, MySQL has nothig to do with Rails or Ruby. In fact, MySQL is written in C, so if you really absolutely must make any ridiculous conclusion about a programming language, based solely on a single incident, then it would be this: C is slow. If you want performance, stay away from C.
(In this particular case, in one interview, they actually did blame Rails: they said that because Rails only supported a single connection to a single database, their MySQL instance simply got overloaded. Within hours of that interview being posted, two Rails developers independently of one another both released Rails plugins to implement multiple connections. The lesson is: only the 80% solutions are in the core. Twitter clearly isn't in the 80%. The plugin API is there for a reason.)
They had problems with the performance and scalability of the overall system. It turned out that, in order to get the product out quickly, they implemented absolutely no caching whatsoever. Even the "static" Twitter homepage was completely dynamically generated for every single request. Again, this had nothing to do with Rails or Ruby. You can bring any site down by turning off their caches, I guarantee you that.
They hit some very bad scalability problems (and the MySQL problems mentioned above are related to that) which were simply caused by the fact that people used the site in a way not anticipated by the developers. Everybody knows that Twitter is a micro-messaging platform. Well, except for the Twitter founders. They had this brilliant idea for a micro content management system.
And so, they did build a micro-CMS. And of course, the central piece of a content management system, is a content repository, IOW a database. Users however used Twitter as a micro-messaging platform. And the central piece of a messaging platform is a message queue.
As a result, MySQL was being used as a message queue. No two things could be further apart than a database (especially a SQL database) and a message queue. The two have almost exactly opposite requirements and constraints.
And of course, the entire architecture was built around that content repository which was now being abused as a message queue.
In response to that, the Twitter developers wrote their own message queue in Ruby, which helped performance and scalability a lot. But not enough. So, they wrote another message queue, this time in Scala.
It is this single rewrite that is wholly responsible for, I would estimate, at leat 70% of all the Rails FUD out there. But, I don't know about you: when I write something that I have absolutely no idea how to write it, and then I write the exact same thing a second time, when I actually do know what the heck I'm doing … the second one is always better than the first. And I suspect that this is the case here, too.
In several interviews, the Twitter developers have pointed out that Ruby on Rails was not responsible for their scaling problems. On the contrary, only the maintainability of Ruby made it possible to do such large-scale architectural changes to fix their scaling problems.
To cut a long story short: today, Twitter is actually using Ruby on Rails for what it was intended to be used: for a web application. And they use a database for storing data and not as a message queue. And they use an actual proper message queue. The message queue and some other backend stuff is written in Scala. The frontend is written in Ruby on Rails. Some stuff is written in C.
And all is peachy.
The real moral of the story here is that you can substitute pretty much any large web app, any language, any framework into the above story and it would still be true. MySpace is one of the slowest, most unreliable websites I know, and that is a .NET site. GitHub is one of the fastest websites I know, while being the biggest hosting platform (it has over a million repositories after just over 2 years, that's more than SourceForge and Google Code combined) and it is written in Ruby on Rails for the frontend, Sinatra for the web service, Ruby for the Git interfacing and Git infrastructure, Erlang for the federation and cloud infrastructure and Node.JS for the download server.
Here's a start
Scaling ROR
Why Rails can run slowly
Framework Preformance Comparison
SO related question
Related interest article Twitter abandons ROR its old I know but I didnt actually know that lol
Short answer
Could potentially sure.
Might be more likely than some other languages.
Depends on the application, the programmer and the architecture.
As I see it - RoR is only a bit slower. At least slower than .Net, cause ruby is interpreted language.
But in general - it depends on quality of developers. RoR app that uses nice caching will work n times faster than .net/java app that loads half database into memory and sends plenty database requests cause of select n+1.
yes it is slower, but in production it will probably only hurt you once your load "exceeds a certain point" ("x requests/sec") and most sites never see more load than that.
How can i write a cloud-aware application? e.g. an application that takes benefit of being deployed on cloud. Is it same as an application that runs or a vps/dedicated server? if not then what are the differences? are there any design changes? What are the procedures that i need to take if i am to migrate an application to cloud-aware?
Also i am about to implement a web application idea which would need features like security, performance, caching, and more importantly free. I have been comparing some frameworks and found that django has least RAM/CPU usage and works great in prefork+threaded mode, but i have also read that django based sites stop to respond with huge load of connections. Other frameworks that i have seen/know are Zend, CakePHP, Lithium/Cake3, CodeIgnitor, Symfony, Ruby on Rails....
So i would leave this to your opinion as well, suggest me a good free framework based on my needs.
Finally thanks for reading the essay ;)
I feel a matrix moment coming on... "what is the cloud? The cloud is all around us, a prison for your program..." (what? the FAQ said bring your sense of humour...)
Ok so seriously, what is the cloud? It depends on the implementation but usual features include scalable computing resource and a charge per cpu-hour, storage area etc. So yes, it is a bit like developing on your VPS/a normal server.
As I understand it, Google App Engine allows you to consume as much as you want. The back-end resource management is done by Google and billed to you and you pay for what you use. I believe there's even a free threshold.
Amazon EC2 exposes an API that actually allows you to add virtual machine instances (someone correct me please if I'm wrong) having pre-configured them, deploy another instance of your web app, talk between private IP ranges if you wish (slicehost definitely allow this). As such, EC2 can allow you to act like a giant load balancer on the front-end passing work off to a whole number of VMs on the back end, or expose all that publicly, take your pick. I'm not sure on the exact detail because I didn't build the system but that's how I understand it.
I have a feeling (but I know least about Azure) that on Azure, resource management is done automatically, for you, by Microsoft, based on what your app uses.
So, in summary, the cloud is different things depending on which particular cloud you choose. EC2 seems to expose an API for managing resource, GAE and Azure appear to be environments which grow and shrink in the background based on your use.
Note: I am aware there are certain constraints developing in GAE, particularly with Java. In a minute, I'll edit in another thread where someone made an excellent comment on one of my posts to this effect.
Edit as promised, see this thread: Cloud Agnostic Architecture?
As for a choice of framework, it really doesn't matter as far as I'm concerned. If you are planning on deploying to one of these platforms you might want to check framework/language availability. I personally have just started Django and love it, having learnt python a while ago, so, in my totally unbiased opinion, use Django. Other developers will probably recommend other things, based on their preferences. What do you know? What are you most comfortable with? What do you like the most? I'd go with that. I chose Django purely because I'm not such a big fan of PHP, I like Python and I was comfortable with the framework when I initially played around with it.
Edit: So how do you write cloud-aware code? You design your software in such a way it fits on one of these architectures. Again, see the cloud-agnostic thread for some really good discussion on ways of doing this. For example, you might talk to some services on GAE which scale. That they are on GAE (example) doesn't really matter, you use loose coupling ideas. In essence, this is just a step up from the web service idea.
Also, another feature of the cloud I forgot to mention is the idea of CDN's being provided for you - some cloud implementations might move your data around the globe to make it more efficient to serve, or just because that's where they've got space. If that's an issue, don't use the cloud.
I cannot answer your question - I'm not experienced in such projects - but I can tell you one thing... both CakePHP and CodeIgniter are designed for PHP4 - in other words: for really old technology. And it seems nothing is going to change in their case. Symfony (especially 2.0 version which is still in heavy beta) is worth considering, but as I said on the very beginning - I can not support this with my own experience.
For designing applications for deployment for the cloud, the main thing to consider if recoverability. If your server is terminated, you may lose all of your data. If you're deploying on Amazon, I'd recommend putting all data that you need persisted onto an Elastic Block Storage (EBS) device. This would be data like user generated content/files, the database files and logs. I also use the EBS snapshot on a 5 day rotation so that's backed up itself. That said, I've had a cloud server up on AWS for over a year without any issues.
As for frameworks, I'm giving Grails a try at the minute and I'm quite enjoying it. Built to be syntactically similar to Rails but runs on the JVM. It means you can take advantage of all the Java goodness, like threading, concurrency and all the great libraries out there to build your web application.
Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 7 years ago.
Improve this question
I was recently approached by a network-engineer, co-worker who would like to offload his minor network admin duties to a junior-level helpdesk tech. The specific location in need of management acts as an ISP for tenants on its single-site property, so there's a lot of small adjustments being made on a daily basis.
I am thinking it would be helpful to write him a winform app to manage the 32 Cisco devices, on-site. I'd like to initially provide functionality which could modify access control lists, port VLAN assignments, and bandwidth limitations per VLAN... adding more to the list as its deemed valuable.
My initial thought was to emulate a telnet session with the network device; utilizing my network-engineer's familiarity with the command-line / IOS interaction. Minimal time would be required to learn Cisco IOS conventions, myself.
Though while searching for solutions, it appears that most people favor SNMP. That, or, their specific circumstances pushed them in the direction of SNMP.
I wanted to know if I've overlooked an obvious benefit of SNMP. Should I be using SNMP? Why or why not?
SNMP is great for getting information out of a Cisco device, but is not very useful controlling the device. (although technically, you can push a new config to a Cisco IOS device using a combination of SNMP and TFTP. But sending a whole new config is a pretty blunt instrument for controlling your router or switch).
One of the other commenters mentioned the Cisco IOS XR XML API. It's important to note that the IOS XR XML API is only available on devices that run IOS XR. IOS XR is only used on a few of Cisco's high end carrier class devices, so for 99% of all Cisco routers and switches the IOS XR XML API is not an option.
Other possibilities are SSH or HTTP (many Cisco routers, switches, AP, etc. have an optional web interface). But I'd recommend against either of those. To my knowledge, the web interface isn't very consistent across devices, and a rather surprising number of Cisco devices don't support SSH, or at least don't support it in the base license.
Telnet is really the only way to go, unless you're only targeting a small range of device models. To give you something to compare against, Cisco's own CiscoWorks network management software uses Telnet to connect to managed devices.
I wouldn't use SNMP, instead look at a little language called 'expect'. it makes for a very nice expect/response processor for these routers.
I have done a reasonable amount of real world SNMP programming with Cisco switches and find Python on top of Net-SNMP to be quite reasonable. Here is an example, via Google books, of uploading a new Cisco configuration via Net-SNMP and Python: Cisco Switch Upload via Net-SNMP and Python. I should disclose I was the co-author of the book referenced in the link.
Everyone's milage may vary, but I personally do not like using expect, and prefer to use SNMP because it was actually designed to be a "Simple Network Management Protocol". In a pinch, expect is ok, but it would not be my first choice. One of the reasons some companies use expect is that a developer just gets used to using expect. I wouldn't necessarily chock up bypassing SNMP just because there is an example of someone automating telnet or ssh. Try it out for self first.
There can be some truly horrible things that happen with expect, that may not be obvious as well. Because expect waits for input, under the right conditions there be very subtle problems that are difficult to debug. This doesn't mean a very experienced developer can't develop reliable code with expect, but it something to be aware of as well.
One of the other things you may want to look at is an example of using the multiprocessing module to write non-blocking SNMP code. Because this is my first post to stackoverflow I cannot post more then one link, but if you google for it you can find it, or another one on using IPython and Net-SNMP.
One thing to keep in mind when writing SNMP code is that it involves reading a lot of documentation and doing trial and error. In the case of Cisco, the documentation is quite good though.
SNMP isn't bad but it may not be able to do everything you need it to do. Depending on the library you use and how it hides the details of interacting with SNMP you may have a hard time finding the correct parts of the MIB to change and even knowing what or how to change them to do what you want.
One reason not to use SNMP is that you can do all the configuration you need using the IOS XR XML API. It could be a lot easier to bundle up the commands you want to send to the devices using that than to interact with SNMP.
I've found SNMP to be a pain for management. If you just need to grab a little data it's great; if you need to change things or use if heavily it can be very time consuming. In my case I'm comfortable with the CLI so a Telnet approach works well. I've written some Python scripts to perform administrative tasks on various pieces of network gear using Telnetlib
SNMP has quite a significant CPU hit on the devices in question compared to telnet; I'd recommend telnet wherever possible. (As stated in a previous answer, the IOS XR XML API would be nice, but as far as I know IOS XR is only deployed on high-end carrier grade routers).
In terms of existing configuration management systems, two commercial players are HP Opsware, and EMC Voyence. Both will probably do what you need. I'm not aware of many open source solutions that actually support deploying changes. (RANCID, for example, only does configuration monitoring, not pre-staging and deploying config changes).
If you are going to roll your own solution, one thing I would recommend is sitting down with your network admin and coming up with a best-practice deployment model for the service he's providing (e.g. standardised ACL, QoS queue, and VLAN names; similar entries in ACLs that have the same function for different customers, etc.). Ensure that all the existing deployed config complies with this BP before you start your design, it will make the problem much more manageable. Best of luck.
Sidenote: before you reinvent the wheel writing another service provisioning system/network management system, try looking for existing ones. I know quite a lot of commercial solutions of various degrees of flexibility/functionality, but I am sure there are quite a lot opensource ones.
Cisco has included menu options for helpdesk applications. Basically you telnet to the box and it presents a nice clean menu (press 1, 2, 3). For more info check this link:
http://www.cisco.com/en/US/docs/ios/12_2/configfun/command/reference/frf001.html#wp1050026
Another vote for expect.
Also, you don't want to allow configuration of your firewalls via either telnet or SNMP - ssh is the only way to go. The reason is that ssh encrypts its payload, and will not expose the privileged management credentials to potential interception.
If for some reason you cannot use ssh directly, consider connecting up an ssh-enabled serial console server to the firewall's console port and configuring it that way.