Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Why some websites delay database updates?

Posted on 2011-09-17
8
Medium Priority
?
410 Views
Last Modified: 2012-06-27
Why some websites such as Wikipedia and some advertising networks delaying updating their database after user changes?

For example: A user add the keyword "Experts Exchange", why do it take time to affect the online campaign while they can update the database the same time?
0
Comment
Question by:Mohamed Abowarda
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
8 Comments
 
LVL 143

Assisted Solution

by:Guy Hengel [angelIII / a3]
Guy Hengel [angelIII / a3] earned 200 total points
ID: 36553558
replication might be 1 reason.
=> some sites are using several spread-over the world databases, so the "update" is not spread immediately to "all" those databases ...
validation another reason
another reason could be that (some) pages are being (re)generated based on content (changes), scheduled or triggered (but not realtime)
0
 
LVL 9

Assisted Solution

by:ghodder
ghodder earned 200 total points
ID: 36553591
It can also be due to content caching. Lots of larger sites use caches to reduce the load on their databases and improve the speed the pages load when you visit them.

Some pages could be configured to have a longer expiry timeout (e.g. if it is not anticipated that the page would be updated more than once per day) so the caching proxy will continue to serve the out-dated page until it reaches the expiry time.
0
 
LVL 13

Assisted Solution

by:khairil
khairil earned 200 total points
ID: 36553632
Other possibility, page like Wikipedia might have to be evaluate first by someone else before it can release the updated information to the mass. After validated all the changes then only the user can access the updated content.
0
Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 111

Assisted Solution

by:Ray Paseur
Ray Paseur earned 200 total points
ID: 36554256
When unauthenticated clients post comments, a moderator might want to review the comments.  I have a church web site that has an open calendar - anybody that wants to can post anything into the calendar.  But for obvious reasons we have a "gatekeeper" that may delete or modify inappropriate content.

Another possibility would make sense if it takes a long time to generate a dynamic page.  Example: The index.php page is only 100K but the complex queries needed to create the page take 10 seconds to run.  Rather than take a 10-second page load time, you can capture the output buffers and write the index.html version of the index.php page.  Then most clients will see the fast, static page.  A CRON job can periodically delete the index.html page, and the 404 handler can call the index.php page to rebuild the static version.
0
 
LVL 12

Author Comment

by:Mohamed Abowarda
ID: 36554338
Sometimes updating a "number" can delay, like for instance updating campaign budget.
0
 
LVL 12

Author Comment

by:Mohamed Abowarda
ID: 36554483
Another possibility would make sense if it takes a long time to generate a dynamic page.  Example: The index.php page is only 100K but the complex queries needed to create the page take 10 seconds to run.  Rather than take a 10-second page load time, you can capture the output buffers and write the index.html version of the index.php page.  Then most clients will see the fast, static page.  A CRON job can periodically delete the index.html page, and the 404 handler can call the index.php page to rebuild the static version.

In websites like Facebook, usually they have billions of records, why the database updates are instantly and don't take a lot of time to load?
0
 
LVL 143

Expert Comment

by:Guy Hengel [angelIII / a3]
ID: 36554545
it can depend on how much $$$ you can invest on hardware and software for your website ...
0
 
LVL 5

Accepted Solution

by:
vop earned 200 total points
ID: 36557092
ISPs generally cache quite a bit of the web traffic passed by them as this can significantly reduce backbone bandwidth requirements.

The delay is proably a combination of this and the phenomena mentioned by other posters.

0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This post looks at MongoDB and MySQL, and covers high-level MongoDB strengths, weaknesses, features, and uses from the perspective of an SQL user.
What we learned in Webroot's webinar on multi-vector protection.
This is a high-level webinar that covers the history of enterprise open source database use. It addresses both the advantages companies see in using open source database technologies, as well as the fears and reservations they might have. In this…
In this video, Percona Solution Engineer Rick Golba discuss how (and why) you implement high availability in a database environment. To discuss how Percona Consulting can help with your design and architecture needs for your database and infrastr…

688 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question