Comments on: The reliability of web services

By: estetik

estetik — Thu, 06 Dec 2007 19:56:02 +0000

Very good article. I don’t believe web services give right information on their frontpages especially about uptime percentages.

By: Dave Smith

Dave Smith — Sun, 01 Oct 2006 15:27:28 +0000

In publishing a service that will be connected to, lights-out, by the public and stakeholders one might not even be aware of, the hope is that the owner of the service considers these aspects in advance. This goes toward the overall strategy and service level agreement (SLA). What is the backup and replication strategy? How reliable is the service expected to be in terms of throughput and uptime? How about data latency - is it going to be updated on a reliable basis? Data accuracy? Is the service something that has solid and ongoing funding as part of a bigger program, is it just a proof-of-concept or pilot, or are there other contingencies to consider in terms of longterm viability? These things may have some impact on whether others will even consider the published service worthwhile… Some plan, or better yet, a published metadata describing these aspects should be on the radar of any service provider.

By: Raj

Raj — Tue, 01 Aug 2006 18:28:45 +0000

Great discussion topic. I’ve been thinking about this a lot lately, and so have many others here: http://wiki.osgeo.org/index.php/WMS_Tile_Caching. The problem with WMS is that there’s a cost/benefit mismatch between what you want–a pretty map–and what it takes to deliver that to you–lots of computation to rasterize vector data. That’s why OGC and others are working on a tiling scheme for WMS so that you can pre-generate your maps and just serve out files, like all the big street mapping sites do now anyway.

By: Chris

Chris — Sun, 30 Jul 2006 21:33:33 +0000

Interesting experiment, Matt. I am working on a Colorado WMS/WFS project at the moment and
reliability is one of the issues that I am curious about. Do you think it has to do with the
particular server hardware or an issue specific to WMS services?

Very interesting.

Chris

By: Jeremy

Jeremy — Tue, 25 Jul 2006 14:13:23 +0000

Good post Matt. We have a project where we integrate around 30 map services in a targeted portal. We use everything from large National services (seamless, Geography Network, etc) to smaller scale services specific to the project (project partners). The major organizations are quite stable actually. The services that are run out of University’s with mostly graduate student help are the ones that go down the most. Check it out here if you are interested. The fun thing about the project is that we have been doing this for about two years and we have statistics/uptime for that entire time period.

Jeremy

By: Dave

Dave — Tue, 25 Jul 2006 13:16:50 +0000

Not to be an ESRI “fan boy” (as Sean Gilles would call me), but this is one reason that I really like the new geodatabase replication that’s coming with ArcGIS 9.2 - you can cascade data between organizations, bi-directionally, at the database level. Since you have all the data locally, and it’s kept in synch with the original source, your application is not dependant on the uptime of the remote service. Of course this functionality is not “free”, but it’s better than relying on inconsistent services for mission criticla datasets

Here’s a link to the web help about GDB Geodatabase Replication

Cheers,

Dave