I am developing an invoice app with Angular + NodeJs + MySql.
The thing is, the app is planned to be used by one employee in his office. No need for online servers.
It is not problematic to deploy the app online, but the internet is unstable in the zone (Latinamerican problem. You may lose connection for hours, and even voltage variations that may shut down the PC).
So the app must be self sufficient to always work offline.
So my questions are:
Can I simply deploy the app offline? Like in local. If that is the case, I would need for everything to be initialized automatically when the user opens the app (server open, database connected...).
If I have no way but to deploy the app online, should I use Firebase? Also, what happen if the internet service shut downs for hours? Is there a way for the database to be available offline and sync when the internet gets back?
You could build the app as an Electron App, then its becomes a locally run program. https://www.electronjs.org/
You can host it anywhere, but turn the app in to a PWA, which means it will work locally in the browser after a successful visit (gets installed with a service worker in browser) For the database it self, you can store data in the browser but some are limited to 5mb of data in the localstorage / sessionStorage / indexdb. Firebase does have some locally cached data. But if the browser is closed it can be lost.
If it needs to run locally i would go the electron route. Its slightly harder to do but it fills out your usecase better.
You can use both ways if you want to be sync like situation you have to hold data if your internet is not working in local storage or indexed db.
and it is fine you can deploy locally also or make one dedicated server which is always on.so any body in same network can use that angular app easily.
Just take care of backup plan when you system corrupt you should have proper backup of database for such scenario.
Related
We currently have an application that runs on one dedicated server. I'd like to move it to OpenShift. It has:
A public-facing web app written in PhP
A Java app for administrators running on Wildfly
A Mysql database
A filesystem containing lots of images and documents that must be accessible to both the Java and PhP apps. A third party ftp's a data file to the server every day, and a perl script loads that into the db and the file system.
A perl script occasionally runs ffmpeg to generate videos, reading images from and writing videos to the filesystem.
Is Openshift a good solution for this, or would it be better to use AWS directly instead (for instance because they have dedicated file system components?)
Thanks
Michael Davis
Ottawa
The shared file system will definitely be the biggest issue here. You could get around it by setting up your applications to use Amazon S3 or some other shared Cloud file system though fairly easily.
As for the rest of the application, if I were setting this up I would:
Setup a scaled PHP application, even if you set the scaling to just use 1 gear this will allow you to put the MySQL database on it's own gear, and even choose a different size for it, such as having medium web gears (that run php) and a large gear that runs the MySQL database. This will also allow your wildfly gear to access the database since it will have a FQDN (fully qualified domain name) that any of your applications on your account can reach. However, keep in mind that it will use a non-standard port instead of 3306.
Then you can setup your WildFly server as whatever size you want, but, keep in mind that the MySQL connection variables will not be there, you will have to put them into your java application manually.
As for the perl script, depending on how intensive it is, you could run it on it's own whatever sized gear with some extra storage, or you could co-locate it with either the php or java application as a cron job. You can have it store the files on Amazon S3 and pull them down/upload them as it does the ffmpeg operations on them. Since OpenShift is also hosted on Amazon (In the US-EAST region) these operations should be pretty fast, as long as you also put your S3 bucket in the US-EAST region.
Those are my thoughts, hope it helps. Feel free to ask questions if you have them. You can also visit http://help.openshift.com and under "Contact Us" click on "Submit a request" and make sure you reference this StackOverflow question so I know what you are talking about, you can ask any questions you might have and we can discuss solutions for them.
I've made a mobile native app with a feed system like Instagram/Twitter. In development mode I was just running a PHP/MySQL Apache local server, but now I need to publish the app and work with a real server. Which kind of server do I need? I just need to send http requests (JSON), loads of them!
Do I just need a hosting server like 1and1? (http://www.1and1.com/linux-web-hosting?__lf=Static)
But this one, it only has 1GB MySQL databases... not enough
Is there any kind of app/server whatever? Which kind of server does Instagram use?
These days lots of users are moving to the cloud.
Check out Amazon EC2: http://aws.amazon.com/ec2/
You can setup a micro instance server and it is very cheap to run tests on and get off the ground. Then if you like how it's running, you can simply upgrade to a more powerful server without having to re-install everything.
It also allows you to scale if your application gets really popular by just cloning the server.
Really worth checking out.
I'm developing a windows store app, I want to test roaming settings, I developed my app using vs2012 on one of my machine, and installed the app using powershell on another machine, then changed the roaming settings, but nothing happend. What should I do?
If you have the application installed on two machines, when you change the roaming settings one machine it will eventually propagate to other machine.
To test this, debug both applications simultaneously and place a breakpoint inside the event you attached to ApplicationData.DataChanged (http://msdn.microsoft.com/en-us/library/windows/apps/windows.storage.applicationdata.datachanged)
Now when you change the roaming settings inside one the applications, the application on the other machine should break when it receives the data.
Be aware that for normal roaming settings it can take anywhere from 5-15 minutes, or longer in some cases. For testing, it is easier to send high priority data - this should take much less time, hopefully less than a minute.
I have developed a mobile web application(html5, jquery, css) packaging PhoneGap in which a encrypted id (after first login) is stored in local storage for authentication when, the user logs in the encrypted id is sent to server and hence he is authenticated. This local storage works fine when I go out of the application and come again, but when I force close the application the local storage gets cleared...and the login is need to be done again...
How can I make the local storage presist even if the application is force closed?
To those of you that are trying to be good little developers and version control their ExpressionEngine sites with git, how do you handle your database?
In my limited experience with multiple developers working on one ExpressionEngine site, we've had to all run off of a single MySQL development database running on a remote web server. For those of you that have tried this, it is PAINFULLY slow. Page loads can easily take 5-10 seconds making development extremely difficult. It would be quicker to work off of a remote development server. I am trying to steer away from working off of a remote MySQL server in order to be able to work from anywhere and not depend on Internet connection speed/quality.
Just wondering how others handle their MySQL databases.
Do all of your developers run off of one central database? Have you dealt with slowness issues like we have?
Do you keep your database under version control? How do you handle export/imports among multiple developers and multiple branches?
With one developer I can import/export/commit the database very easily but as soon as you add another developer to the mix, it gets very VERY muddy. Looking forward to hearing everyone's thoughts on this mammoth topic.
Thanks!
It seems there is a lot of time lost on failing DNS requests, with a remote database.
Start your MySQL server with start mysqld with --skip-name-resolve. (More information on this topic can be found here: http://dev.mysql.com/doc/refman/5.0/en/host-cache.html)
Having a remote database still seems to be the best way for us to work on a project with multiple developers.
I almost always use a central database for development. Depending which host you use, the speed difference may not be huge.
Obviously, if you're not making changes to the database, i.e. only doing template development, keeping the database in sync is not as needed, so you could potentially bring up a local copy of the database. You just have to remember to repeat any database changes, if you do end up making some.
As far as version control, I keep a copy of my base EE install's SQL file in my base repository. Other than that I don't usually keep copies of the database in Git, so I don't do a lot of importing/exporting, etc.
Have you looked at the EE Profiler recently? You'll probably notice in the neighborhood of 20-80 queries on your home page depending on it's complexity.
The problem is that, for each query, MySQL must execute a remote request for data, download the response, and then present ExpressionEngine it's data. The 20-80 round trips to the database is what's causing your delay and I don't think there is much you can do about it. When using a remote (outside our network) database, I get the same delay as you.
When MySQL is running on your machine or the production server, it doesn't have the added network requests causing latency in it's requests for data. This is the difference.
As for fixes, all you can do is move to a database hosted on your internal network. We have a Linux machine that mimics our production environment that we use for staging. Since it's on our network, we can use the local IP address in our database.php file. This is much faster.
The problem that we still have is the issue of channels/fields/entries. When a developer is working on a new section, they'll likely need to create a new channel and fields and/or new entries. When we're ready to push that functionality to production, we have to manually make those changes on the production server as there is no way to reliably export them. I am hopeful of this addon though---we'll see.
In my company (4 developers) we each run our own DB locally. But recently I tested Rackspace Cloud Databases (but there are other cloud db providers) for a heavy DB that could become difficult to run on a little laptop. It's relatively less expensive than running our own db server, and it can be setup or deleted in the minute.