Scenario: You are going to do scheduled database maintenance. You will hence be unable to serve dynamic content (just assume the caching system in front of the database also needs to be maintained).
During that time, what's the correct way of handling web requests trying to access a dynamic resource?
What's the correct HTTP error code, if any, that goes along with the notice that your service is currently not available? Should you use errors in the 5XX range?
What are the implications in terms of SEO? Will it hurt if search engine crawlers try to access your site and see lots of error codes or pages with the same notice instead of dynamic content? Can you easily recover from that?
503 Service Unavailable is the correct response to use in this situation.
Depending on how your site works, you could just put up a static HTML page replacing everything saying that the site is undergoing maintenance.
Related
I'm running PageSpeed Insights on my website and one big error that I get sometimes is
Reduce initial server response time
Keep the server response time for the main document short because all
other requests depend on it. Learn more.
React If you are server-side rendering any React components, consider
using renderToNodeStream() or renderToStaticNodeStream() to allow
the client to receive and hydrate different parts of the markup
instead of all at once. Learn more.
I looked up renderToNodeStream() and renderToStaticNodeStream() but I didn't really understand how they could be used with Gatsby.
It looks like a problem others are having also
The domain is https://suddenlysask.com if you want to look at it
My DNS records
Use a CNAME record on a non-apex domain. By using the bare/apex domain you bypass the CDN and force all requests through the load balancer. This means you end up with a single IP address serving all requests (fewer simultaneous connections), the server is proxying to the content without caching, and the distance to the user is likely to be further.
EDIT: Also, your HTML file is over 300KB. That's obscene. It looks like you're including Bootstrap in it twice, you're repeating the same inline <style> tags over and over with slightly different selector hashes, and you have a ton of (unused) utility classes. You only want to inline critical CSS if possible; serve the rest from an external file if you can't treeshake it.
Well the behavior is unexpected, I ran the pagespeed insights of your site and it gave me a warning on first test with initial response time of 0.74 seconds. Then i used my developer tools to look at the initial response time on the document root, which was fairly between 300 to 400ms. So I did the pagespeed test again and the response was 140ms. The test was passed. After that it was 120ms.
See the attached image.
I totally think there is no problem with the site. Still if you wanna try i would recommend you to change the server or your hosting for once, try and go for something different. I don't know what kind of server you have right now where the site is deployed. You can try AWS S3 and CloudFront, works well for me.
I would like to know how do CDNs serve private data - images / videos. I came across this stackoverflow answer but this seems to be Amazon CloudFront specific answer.
As a popular example case lets say the problem in question is serving contents inside of facebook. So there is access controlled stuff at an individual user level and also at a group of users level. Besides, there is some publicly accessible data.
All logic of what can be served to whom resides on the server!
The first request to CDN will go to application server and gets validated for access rights. But there is a catch - keep this in mind:
Assume that first request is successful and after that, anyone will be able to access the image with that CDN URL. I tested this with Facebook user uploaded restricted image and it was accessible with the CDN URL by others too even after me logging out. So, the image will be accessible till the CDN cache expiry time.
I believe this should work - all requests first come to the main application server. After determining whether access is allowed or not, a redirect to the CDN server or access-denied error can be shown.
Each CDN working differently, so unless you specify which CDN you are looking for its hard to tell.
I'm building some reporting tool. Ideally I want to avoid going through web server logs myself and use (some of) the power of Piwik.
The stuff I get from the visitor log would be a good start, this is at http://example.com/piwik/index.php?module=CoreHome&action=index&idSite=1&period=day&date=yesterday#/module=Live&action=getVisitorLog&idSite=1&period=day&date=yesterday
Unfortunately I can't find a getVisitorLog action in the HTTP API docs at
http://developer.piwik.org/api-reference/reporting-api#Actions (and it's also not an undocumented feature, method=Actions.getVisitorLog gives me
The method 'getVisitorLog' does not exist or is not available in the module '\Piwik\Plugins\Actions\API'.
Is there another way to get to this? Or should I write a plugin for Piwik?
Apparently it is possible through the Live plugin API:
http://developer.piwik.org/api-reference/reporting-api#Live
This works as desired:
http://example.com/piwik/index.php?module=API&method=Live.getLastVisitsDetails&format=JSON&idSite=1&period=day&date=2015-07-21&expanded=1&token_auth=XXXXX&filter_limit=100
Good afternoon.
We've recently noticed a growing number a API call failure when trying to reach your Google Static Maps API.
Issues initially seemed intermittent, but seems to happen a lot more frequently, if not: all the time.
What steps will reproduce the problem? Please provide a link to a
demonstration page if at all possible, or attach code.
Totally works locally or in a web browser
Sends out a 500 Internal Server Error when on our staging/production systems
Could that be related to authentication? To my knowledge, API keys aren't really enforced locally, but definitely checked for when application runs on a live system.
Doesn't report as an error in our Google API Console. Just as a regular successful call.
Sample URL:
https://maps.googleapis.com/maps/api/staticmap?center=38.121504,-122.590525&scale=2&visual_refresh=true&size=280x188&key=OUR_BROWSER_API_KEY&markers=icon:http://stage.hometrendsreport.com/images/mini_orange.png|shadow:false|38.121504,-122.590525&markers=icon:http://stage.hometrendsreport.com/images/mini_blue.png|shadow:false|38.121073,-122.5932|38.123742,-122.591363|38.123981,-122.590448|38.124226,-122.589497|38.118754,-122.588585|38.119648,-122.587095|38.123877,-122.587494|38.118187,-122.592065|38.118038,-122.591357&markers=icon:http://stage.hometrendsreport.com/images/mini_gray.png|shadow:false|38.118442,-122.589865|38.118442,-122.589865|38.12166,-122.602269|38.116919,-122.571937
Here's our code snippet, using ruby/paperclip:
self.picture = URI.parse(google_map_url.to_s)
return self.save
Any idea why this is happening?
Any help gladly appreciated.
Best regards,
For developers viewing this issue: please click the 'star' icon to be
notified of future changes, and to let us know how many of you are
interested in seeing it resolved.
When I access the link I get an "invalid API key", so the API Key may be the problem. I believe there are also much lower quota for requests to the static map API, while testing you may have exceeded your quota.
I'm working on building a Silverlight application whereas we want to be able to have a client hit a url like:
http://{client}.domain.com/
and login, where the {client} part is their business name. so for example, google's would be:
http://google.domain.com/
What I was wondering was if anyone has been able, in silverlight, to be able to use this subdomain model to make decisions on the call to the web server so that you can switch to a specific database to run a query? Unfortunately, it's something that is quite necessary for the project, as we are trying to make it easy for their employees to get their company specific information for our software.
Wouldn't it work to put the service on a specific subdomain itself, such as wcf.example.com, and then setup a cross domain policy file on the service to allow it to access it?
As long as this would work you could just load the silverlight in the proper subdomain and then pass that subdomain to your service and let it do its thing.
Some examples of this below:
Silverlight Cross Domain Services
Silverlight Cross Domain Policy Helpers
On the server side you can check the HTTP 1.1 Host header to see how the user came to your server and do the necessary customization based on that.
I think you cannot do this with Silverlight alone, I know you cannot do this without problems with Javascript, Ajax etc. . That is because a sub domain is - for security reasons - treated otherwise than a sub-page by the browsers.
What about the following idea: Insert a rewrite rule to your web server software. So if http://google.domain.com is called, the web server itself rewrites the URL to something like http://www.domain.com/google/ (or better: http://www.domain.com/customers/google/). Would that help?
Georgi:
That would help if it would be static, but alas, it's going to all be dynamic. My hope was to have 1x deployment for the application, and to use the http://google.domain.com/ idea to switch to the correct database for the user. I recall doing this once when we built an asp.net website, using the domain context to figure out what skin to use, etc.
Ates: Can you explain more about what you are saying... sounds like you are close to what I am trying to come up with. Have you seen such a tutorial for this?
The only other way I have come up with to make this work is to have a metabase that when the user logs in, it will switch them to the appropriate database as required... was just thinking as well that telling Client x to hit:
http://ClientX.domain.com/ would have been sweeter than saying to hit http://www.domain.com/ and login. It seemed as if they were to hit their name, and to show it personalized for them right from the login screen would have been much more appealing for the client base.
#Richard B: No, I can't think of any such tutorial that I've seen before. I'll try to be more verbose.
The server-side approach in more detail:
Direct *.example.com to the same IP in your DNS settings.
The backend app that handles login checks the Host HTTP header (e.g. the "HTTP_HOST" server variable in some platforms). That would contain the exact subdomain.example.com that the client used for reaching your server. Extract the subdomain part and continue...
There can also be a client-side-only approach. I don't know much about Silverlight but I'm assuming that you should be able to interface Silverlight with JavaScript. You could read document.location with JavaScript and pass it to your Silverlight applet, whereon further data fetching etc. logic would rely on the subdomain that was passed in by JavaScript.
#Ates:
That is what we did when we wrote the ASP.Net system... we pushed a slew of *.example.com hosts against the web server, and handled using the HTTP headers. The hold-up comes when dealing with WCF pushing the info between the client and the server... it can only exist in one domain...
So, for example, when you have {client}.example.com and {sandbox}.example.com, the WCF service can't be registered to both. It also cannot be registered to just *.example.com or example.com, so that's where the catch 22 is coming in at. everything else I have the prior knowledge of handling.
I recall a method by which an application can "spoof" another domain name in certain instances. I take it in this case, I would need to do such a configuration? Much to research yet I believe.