I'm currently working on a web application which shows data about remote microcontollers which collect weather data. Data is sent to an application through a proprietary protocol, and ends up being stored in a ODBC accessible database in a Windows machine.
I've written a Django application, taking a snapshot of that data, showing those remote units as Google Map Markers that show a nice Google Visualization plot. Up to this point, everything went just fine.
The problem I'm facing here is that the ODBC accesible database is running in a Windows machine and the Django app in a remote server under Linux.
I need to synchronize data from the Windows box to the remote django app. I'm planning to write a transaction-oriented sync protocol. But I don't want it to be too complex, though I must prevent stalled sync states.
Any thoughts about the problem?
I've come up with a RESTful API with TastyPie on the server, and a PyQt4 GUI in the client using httplib2 as client library.
Since I'm using Python 2.7, I use native json module (which tastes much like simplejson).
Final notes, I'm building an executable with cxfreeze.
Related
I'm using Parse.com SDK services for my Android app.
I've seen that Parse had released their Android SDK as an open source project on Github on this address.
My app is almost finished, and when I'm uploading it to the Play Store, I don't want to be controlled by Parse.com (I mean that I don't want to be blocked someday, or I don't know that), so I want to move my whole database to my own server that hosted on a secure company.
I've checked the open source project on Github and realized that all I need to use it on my own server is to generate an Application ID and a client key.
So I want to ask if someone knows how to generate an Application ID and a client key of Parse to use it on my own server, or that you maybe knows another way of moving it to my server? And one more question: Today I'm using also Facebook SDK with my app. If I will move my database to my own server, will I still be able to use Facebook SDK on my app?
Thanks!
I have write an article about how to migrate parse to a custom server.
https://medium.com/#jcminarro/run-parse-server-on-your-own-server-using-digitalocean-b2a7d66e1205
There's a massive difference between Parse open-sourcing their SDKs compared to revealing their entire backend architecture and its configuration.
The open-sourced SDKs are essentially wrappers for Parse's REST API along with some convenience functions and logic for natively interpreting the JSON data Parse is transmitting.
At a high level, Parse uses MongoDB for its core database and is entirely hosted using AWS (Amazon Web Services). The entire architecture is highly complex and is not something you could just drag and drop onto your own software stack or hardware backend.
To help give you a better idea of how Parse achieves all of their services, here's an interesting presentation their Dev Ops team gave at an AWS convention. Suffice it to say, hosting the backend services for over 180,000 apps requires a complex infrastructure and that is the "secret sauce" so to speak for Parse and is why Facebook purchased them for over $85 million two years ago.
In my pursuit to write a Chrome packaged app, I am struggling to get my data synchronized to the app so that it can be used in offline mode.
My data lives on a server and I access it trough a restful service in this case I use.net MVC WebApi
What I have tried: Using Breezejs because of the easy offline capabilities ; the problem is that
window.localStorage
is not available in packaged apps, I did tried switching it out for IndexedDB but no luck.
I tried chrome.storage that worked great with the build in sync but it is not a big truck and that is what I need at least a 10tunner.
So my Question; is there a silver bullet that has some XMLHttpRequest implementations, that makes it easier to get data from a restful service, storing it to IndexedDB so that it can be used offline and when going online syncs the changes, that is compatible with packaged apps.
I know I must probably write my own but if someone already went trough all the hoops and complexities of synchronization that can guide me it will be awesome.
Have you looked at using the syncFileSystem API ?
As long as you are happy to sync your data into Google Drive, this api should meet your needs for not implementing sync code yourself and still working offline.
I have a unique set-up I am trying to determine if Heroku can accommodate. There is so much marketing around polygot applications, but only one example I can actually find!
My application consists of:
A website written in Django
A separate Java application, which takes files uploaded by users, parses them, and stores the data in a database
A shared database accessible by both applications
Because these user-uploaded files can be enormous, I want the uploaded file to go directly to the Java application. My preferred architecture is:
The Django-generated webpage displays the upload form.
The form does an AJAX submit to the Java application
The browser starts polling the database to see if the Java application has inserted the data
Meanwhile the Java application does its thing w/ the user-uploaded file and updates the database when it's done
The Django webpage AJAX-refreshes a div with the results of the user upload once the polling mechanism sees that the upload is complete
The big issue I can't figure out here is if I can get both the Django the Java apps either running on the same set of dynos or on different dynos but under the same domain to avoid AJAX cross-domain issues. Does Heroku support URL-level routing? For ex:
Django application available at http://www.myawesomewebsite.com
Java application available at http://www.myawesomewebsite.com/javaurl/
If this is not possible, does anyone have any ideas for work-arounds? I know I could have the user upload the file to Django and have Django send the request to Java from the server-side instead of the client side, but that's an awful lot of passing around of enormous files.
Thanks so much!
Heroku does not support the ability to route via the URL. Polyglot components should exist as their own subdomains and operate in a cross-domain fashion.
As a side-note: Have you considered directly uploading to S3 instead of uploading to your app on Heroku which will then (presumably) upload to S3. If you're dealing with cross-domain file uploads this is worth considering for its high level of scalability.
I'm working on a personal project that consists of a linux dev board and temperature sensor. I'd like to see a nice web 2.0 real time plot of the tempature from anywhere in the house. Coming from hardware/driver background so i'm not very familar with databases or webservers. I'm stuck trying to figure out how i can send new temperature values from an application to a local web server (also running on the dev board) which can be simulataneously viewed from a client web browser. I've attached a picture which shows what i'm trying to do:
http://img193.imageshack.us/img193/4742/92898822.jpg
I've written the driver, application and played around making an app using GWT. I'm stuck trying to figure out how to make the server-side application and database i.e. Do i need to make a seperate executable that embeds SQL to talk to both application and client via http or is there an easier, existing way to do this?
Thanks in advance.
Kevin
GWT is usually used with a Java application server. You can use JSON or XML to communicate with any kind of server, but I don't know how easy this is.
In a not embedded server you would install Java and an application server. You would also install a database server, but for simple projects you could avoid this by using an embedded DB like HSQL or Derby. For your situation I don't believe this is necessary.
The question is what kind of application server can you use in your platform? All application servers support some kind of CGI communication. This way you could connect your server with the application that samples the temperature values. I don't think there is a need for SQL or an embedded database.
I want to be able to synchronize several text files on a user's PC in real time from my web application. Basically I want a few data files on the local PC to mirror the state of a user's data in my web application so if the web application or the user's internet connection is lost he can use those data files to get some critical info (possibly using html/javascript code stored in with those files that would run in offline mode on those data files.)
I know that google gears has a lot of interesting tools for working with offline state, but I'd prefer an even simpler application in html/javascript that wouldn't be as reliant on google gears. I'd rather use google gears to just create those files and slowly keep them in synch with the web application's version of data throughout the day.
Update on answers:
PersistJS is a good suggestion I will look into, but I was hoping people would direct me towards really good Google Gears tutorials resources.
You can save data on the browser using PersistJS, which uses the best client-side persistent storage mechanism it can find, supporting:
Flash
Google Gears
HTML 5 storage specs
browser-specific extensions
cookies
When your app reconnects, you can resync. Creating and reading text files is something the browser will generally block your web site from doing.
Risking of stating the obvious; if you want to store user state locally, isn't cookies the standard way?
maybe more then one cookie will be needed, but that sounds like the simplest of ways.
You're going to need to make an ActiveX control and a FireFox plugin to get these permissions. Short of that I agree with orip try using PersistJS
You can ask the user to download a subversion client that is predefined to interface with your subversion server only. Then write your web application to interface with the subversion service from your side only.
There is a good deal of security harm associated with granting access to a user's file system so you will want to lock down all possible points of exploitation. You will want to ensure that the user cannot access the subversion server except through the client that you ask them to install. You will want to ensure the connection between the application server and the subversion server is extremely secure so that the transmission path cannot be compromised and that malicious logic that may be loaded onto the application server cannot access the subversion server. I would say to encrypt the transmission path between those two servers and put the subversion server behind the firewall separating your network DMZ. I would also suggest use a challenge/response mechanism between the application server and the subversion server to prevent malicious code from appearing to be legitimate decisions made on the application server. Also, ensure that data only flows form the application server to the subversion server in a unidirectional fashion only, because if there is malicious logic planted on your application server then any data that comes from the subversion server is compromised without even accessing that server.
you could use the File System Object FSO through javascript, however it is dependant on Microsoft as it is an ActiveX control, it would also require permissions in the browser, or perhaps a HTA (HTML Application).
http://www.webreference.com/js/column71/
Its a real security issue so most avenues are closed down inhrentley.
Inherently the web model was designed not to authorize upstream from server to client. Now things are changing slowly maybe could you do this with Websocket ?