We are using pouchdb with couchbase in my angular web app. We have around 100k documents on the server. The initial sync takes about 30 minutes on a stable and excellent internet connection. I have noticed that there is an http call per document in many instances where us it reports error 406 unsupported error when pouch tries bulk_get via POST method.
Is there anything I can do to speed the sync up? Or it is designed like that and I have to live with it? The couchbase version is 2.1 but I don't mind upgrading it to the latest version.
Related
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.
I have a Node.js web server that uses express and spdy to serve RESTful API endpoints over http2. As you can see from the screenshot attached, some of my requests are getting stalled from 15 to 20 seconds and it only happens in Chrome.
The entire reason we upgraded to http2 was so that we didn't have to do domain sharding to avoid the queuing wait times. Is there any way I can overcome this? I also have the HTTP2_SESSION logs from Chrome's network-internals tool if those would be helpful.
Here's the screenshot of the absurd amount of stalled time, which is accounting for 80% of our total time:
EDIT:
The npm package is called SPDY. It still uses HTTP/2. I couldn't get Node.js' native http2 module working with express.
EDIT 2:
Paste bin link to the http2 session logs
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 facing a problem with a 3-tier application. It uses IIS and SQL Server. And the problem is that sometimes (longer requests cause higher probability) client does not receive response from IIS. It hangs when there is no activity ON SQL Server, and when even when I kill an SQL Process I get no response with an exception. When I examine data after these hangs I find that my SQL requests have succeeded, so the problem appears to be on IIS. Unfotunately I don't have much control over the place where the application is hosted and I cannot reproduce the problem. There can be many answers to this question, but at least I need a hint in what direction I should investigate.
UPDATE: I also have an app running on the same server that does a small job: it inserts around a 100 lines line-by-line into a database. Artificially I made it run for about 10 minutes (by putting xlock on the table). After removing the xlock the process on IIS continued running and successfully inserted those 100 lines. However, control never returned to the client thereafter, it just waited indefinitely. It looks like this is a problem when returning a response to the client after a long running process.
BTW, this is not a website, but a WinForms app that uses Remoting.
If you're sure that SQL Server is returning to IIS, then you might want to check the IIS logs to see what might be happening to the request. The normal location for these logs is %SystemRoot%\system32\Logfiles\<service_name>.
If you're not sure about SQL Server, you might access the SQL logs, run Profiler, or check the Windows system logs for errors, run your site in debug in Visual Studio or add your own logging to your app to figure out which step it's hanging on.
I have finally figured out where the problem is. The application is run on a web farm and there is a balancer server between the client and IIS. There was a too small timeout on the balancer. For some reason it is not quite friendly with .net remoting and it doesn't return any timeout exceptions to the client. The issue has been solved by increasing the timeout.
I have an ASP.Net 3.5 Application hosted on Windows Server 2008 machine using IIS 7. There is a seperate application pool for this application.
The problem I have is that as soon as 2-3 users access website simultaneously, it starts throwing exceptions on almost any task performed say e.g. an exception during logging in the user using built in aspnet_membership. The same things work fine when there is only one user using it.
Any suggestions what things I need to test for?
Thanks,
Ali
I had some problem like this for some web-application, but in my case I was using IIS 6.0. After analyzing the application by means of some DevPartner tools for analyzing memory usage we realize that some components were consuming excessive resources, by replacing the toolkit we were using for simple .Net controls the applications stop crashing. Most of the crashes are due to problems in code. Also check the web config in the following points: sessionState, authentication. Disable custom errors (customErrors) to view the error details. See the application event's log to check the error description.
The first thing I do when setting up a website of this nature is to uncouple the session state from InProc to StateServer. Oftentimes I find that an application recycle or even an application level exception can cause the w3wp.exe process to crash and reload which dumps session errors. As with #Arce Brito's recommendation, you should do everything you can to find the root cause of the exception as decoupling the session will really only mask the symptom.