I need to be able to access a mySQL database from my iPhone, for both read and write ops. Instead of using MCPKit (due to security and speed considerations), I'd like to access the db through a separate service. The app is iPhone SDK, so I need to get data back in XML form, not as a web page.
I am trying to decide whether to write a Java web service (SOAP) to provide this link, or to just throw together a PHP script on the server side. I can create either solution, but I don't know enough to figure out the advantages/disadvantages of the choice. Please help; thank you!
If you're writing both the client and the server, and performance isn't a significant issue, then the primary remaining consideration is development time.
So, what tools do you have at your disposal? Which platform will allow you to do this with the least amount of work? If it's a toss-up between the two, then pick the one you're most familiar with.
Related
I am sorry in advance; I am just learning Web development and my knowledge of it is quite limited.
I will describe my problem first.
I have relatively large amount of data (1.8-2 GB), which should be hidden from a public web access. However, a user should be able to request via url call a specific small subset of data and see it on his / her webpage.
Ideally, I would like to write a program on a web server. Let's call it ./oracle, which stores the large amount of data in primary memory.
Each web user should be able to make a specific string calls to oracle and see oracle'sresponse on a web page as html elements.
There should only one instance of oracle, and web users should make asynchronous calls to it.
Can I accomplish the above task with FastCGI or any other protocols?
If yes could you please explain which tools / protocols should I use / learn?
I would recommend setting up an Apache server because it's very common and you'll be able to find a lot of answers to any specific questions here on StackOverflow already.
You could also look into things like http://Swagger.io which can help you generate your API.
Unfortunately, everything past this really depends on what you use to set up your server. Big picture though:
You'll need to open up a port to listen to incoming requests
You'll need to have requests include the parameters they want to send to oracle
You could accomplish this the URI, like localhost/oracle-request?PARAMETER="foo"
You could alternatively use JSON in the body of the http request
Again, this largely depends on how you set up step 1
You'll need to route those requests to the oracle
This implementation depends entirely on step 1
You'll need to capture the output from the oracle and return it to the user
Once you decide on how you want to set up your server, feel free to edit your question and we may be able to provide more specific help.
I need to design and implement a Java web application that can be used by multiple users at the same time. The data that is handled by this application is going to be huge and may take about 5 minutes for a page to display the results(database records).
I had designed this application using HTML, Servlets and JSP. But when two users would try to get the records, only one user was able to view the results while the other faced an error.
I always thought a web application would take care of handling multiple users but this is not the case.
Any insights on this would be highly appreciated.
Thanks.
I always thought a web application would take care of handling multiple users but this is not the case.
They do if they're written correctly. Obviously yours is not. That's all we can tell you unless you give more information, most importantly details of the error shown to the second user.
One possibility is that everything is OK on the web layer but your DB access for the first user causes an exclusive lock so that the second user cannot access the data at the same time. This could be fixed by using non-exclusive read locks. How to do that depends mainly on what DB you're using.
Getting concurrency right requires you to choose the correct tools and use them correctly. It doesn't just happen magically because it's a web app.
What are are using to develop this web-application? If you are developing it in your own way from the start I must say you are trying to re-invent the same wheel which has been already created and enhanced by very solid frameworks.
I suggest you analyze your requirements thoroughly and study some available frameworks. Let them handle the things like multi threading and other aspects in the best possible manner.
Handling multiple request at a time is a container work and as an application developer we have to concentrate how we are handling and processing those requret being forwarded by the container.
I must suggest you to get some insight how web-application work and how request -response cycle happens
I have created a small game in Java and I would like to add the ability for a player to publish his highscores online.
I'm willing to write the server software myself (it's easy these days with Ruby Mongrel, or even C++). I just need to have some sort hosting. One solution that immediately comes to mind is Amazon EC2. But that's kind of expensive for my needs. Since the requirements are very minimal (I don't even need a website, just a web service) I think there may be a cheaper solution out there.
Does anyone know of a free or cheap provider for this kind of thing?
Update
For those interested, this is solution I came up with:
a SliceHost
purchased a domain name
C++ HTTP server
built upon the Poco HTTPServer
uses SQLite database via Poco Data
Server implements a REST API supporting
High Score table
/hs content type deduced from accept header
/hs.xml forces xml
/hs.txt forces plain text
/hs/add html form, does a POST using XMLHttpRequest
/hof Hall of Fame, content type deduced from accept header
/hof.txt forces plain text
/hof.xml forces xml
game: my own Tetris clone written in Clojure
Something like Slicehost or any other small-scale VPS provider could probably work. You might even be able to write it as a small app and publish it on Google App Engine, which is free up to a certain point.
google app engine comes to mind: http://code.google.com/appengine/
I have a web-based interface for handing invoices, customer records and other transaction records which interacts currently with a database of all the aforementioned stored upon the same machine. As you can imagine, this is quite a simple set-up consisting of a web-app (PHP) and a database (MySQL). However, the ideal scenario is to keep the records on the machine they are currently on (easy) and move the web-app to another server within the same network (again, easy) ... but in addition, provide facilities on a public-facing website for managing accounts by customers and so forth. The problem is this - the public-facing web server is located in a completely separate location as it is a dedicated server provided by a well-known ISP.
What would be the best way to enable the records to be accessible from this other server whilst ensuring that all communications are secure. Speed is not a huge factor, although any outages on either side should be handled gracefully. Initially my thoughts went towards web services (XML-RPC/SOAP/Hessian), but these options seem to present difficulties (security being the main one, overcomplexity as well).
The web-app must remain PHP-based. The public-facing site is likely to be PHP-based as well, although Python (likely using Django) is another option. The introduction of any other technologies (Java etc) is not a problem, although it is preferred if they be Linux-friendly (so .NET would not be the best fit here).
Apologies if this question is somewhat verbose and vague. I am testing the water somewhat in regards to this kind of problem. Any advice or suggestions gratefully received.
I've done something similar. You can expose a web service to the internet that will do the database access, but requests to the service must match a strong hashed and salted password (which will be secured on the ISP's server in the DMZ.)
Either this or some sort of public/private key encryption scheme.
OK, this might seem a bit silly, but what if you just used mysql replication?
Instead of using all sorts of fancy web services, just have a master sql server on one machine, then have it replicate to another server that holds the slave sql server as well as the web app
At my day job we have load balanced web servers which talk to load balanced app servers via web services (and lately WCF). At any given time, we have 4-6 different teams that have the ability to add new web sites or services or consume existing services. We probably have about 20-30 different web applications and corresponding services.
Unfortunately, given that we have no centralized control over this due to competing priorities, org structures, project timelines, financial buckets, etc., it is quite a mess. We have a variety of services that are reused, but a bunch that are specific to a front-end.
Ideally we would have better control over this situation, and we are trying to get control over it, but that is taking a while. One thing we would like to do is find out more about what all of the inter-relationships between web sites and the app servers.
I have used Reflector to find dependencies among assemblies, but would like to be able to see the traffic patterns between services.
What are the options for trying to map out web service relationships? For the most part, we are mainly talking about internal services (web to app, app to app, batch to app, etc.). Off the top of my head, I can think of two ways to approach it:
Analyze assemblies for any web references. The drawback here is that not everything is a web reference and I'm not sure how WCF connections are listed. However, this would at least be a start for finding 80% of the connections. Does anyone know of any tools that can do that analysis? Like I said, I've used Reflector for assembly references but can't find anything for web references.
Possibly tap into IIS and passively monitor the traffic coming in and out and somehow figure out what is being called and where from. We are looking at enterprise tools that could help but it would be a while before they are implemented (and cost a lot). But is there anything out there that could help out quickly and cheaply? One tool in particular (AmberPoint) can tap into IIS on the servers and monitor inbound and outbound traffic, adds a little special sauce and begin to build a map of the traffic. Very nice, but costs a bundle.
I know, I know, how the heck did you get into this mess in the first place? Beats me, just trying to help us get control of it and get out of it.
Thanks,
Matt
The easiest way is to look through the logs, but if that doesn't include the referrer than you may also want to monitor what is going out from your web to the app server. You can use tools like Wireshark or Microsoft Network Monitor to see this traffic.
The other "solution" and I use this loosely is to bind a specific web server to app server and then run through a bundle and see what it is hitting on the app server. You could probably do this in a test environment to lesson the effects on the users of the site.
You need a service registry (UDDI??)... If you had a means to catalog these services and their consumers, it would make this job of dependency discovery a lot easier. That is not an easy solution, though. It takes time and documentation to get a catalog in place.
I think the quickest solution would be to query your IIS logs and find source URLs which originate from your own servers. You would at least be able to track down which servers your consumers are coming from.
Also, if you already have some kind of authentication mechanism in place, you could trace who is using a particular service based on login.
You are right about AmberPoint. There are other tools that catalog the service traffic and provide reports showing what is happening to your services. Systinet, SOA Software and Actional also has a products similar to Amberpoint but Amberpoint has a free-ware version, I believe.