Computing, GIS and Archaeology in the UK

Apologies to the couple of people who were kind enough to report portable GIS bugs on the launchpad site, only to have their bugs totally ignored.  I didn’t set things up properly, and wasn’t getting email notifications. I’ll deal with the issues and post a fix if I can, and now I am getting notifications, so if anyone else finds any issues do let me know. I also don’t know how I managed to lose my contact form, but it’s back now. Must have been pixies…

A quick post to give people a heads up that there seems to be a google groups problem affecting the portable-gis group, amongst others.

If you have signed up with a googlemail account (not gmail, or any other email account) then your messages may get bounced back with a permissions error.  This seems to be a general problem affecting many groups, so no doubt a fix is in progress, but just so you know, I’m not blocking anyone (hell, I can’t post to my own group at the moment!).

OK, I’m excited to announce that the new version of Portable GIS, complete with the latest versions (as of today- I have to draw the line somewhere) of all the software, is now in testing phase and pretty much ready to release. It’s a bit slicker that the previous version, and comes with some extra software and utilities.

Here is my problem: the last release weighed in at just less that 1GB downloaded, but the new one looks like coming in at approx 1.6GB though I’m going to zip it up in an exe which might help a bit. Software tends to increase in size from version to version, so some “bloat” is unavoidable, but is 1.6GB excessive?

I have a couple of options that I can take to reduce the size. The first is to strip out programmes, so that, for instance, there is only 1 desktop GIS package, or only 1 map server package. The second is to turn this setup into a Portable App, which gives me options to compress the files. I have previously been reluctant to go down the second route because I want the files in Portable GIS to be as similar to those in a standard download as possible, so that people can dig in and see what’s going on and use Portable GIS as a spring board to installing the apps themselves. I worry that “Portable-ising” the files will alter them in some way, but if someone can reassure me about that it’s something to consider.

So, questions:

1. Is 1.6GB excessive for a download of this type?
2. Should I only provide one desktop package and one map server?
3. Should I turn Portable GIS into a fully fledged portable app?

Thanks for your feedback!

Part of my fabulous new plans for portable gis (which will be revealed soon-ish) involve including a database replication option. This might or might not work on the USB drive, but it needs to be open source, portable, and connect to postgresql at the very least. I have been looking at a couple of options for this, without a vast amount of success, it has to be said.

The packages that I have tried are: Daffodil Replicator, dbreplicator (a fork of daffodil replicator), Symmetric-DS, and db -connector for Funambol. Of these, daffodil and dbreplicator seem like the best bet as they will attempt to do some conflict resolution (eg when the same record is added/altered in both databases). They are also java-based, so should be nicely configurable. Symmetric-DS works well, but doesn’t do conflict resolution, so that kind of rules it out for me. I don’t really know about db-connector for funambol as the documentation that I found was quite out of date and I didn’t get very far with it.

So, daffodil replicator and dbreplicator…

They are quite easy to set up, although the documentation in both cases assumes rather more end-user knowledge than perhaps they should do. Basically you find an appropriate jdbc jar file for your database, grab log4j.jar from somewhere, and tell daffodilreplicator/dbreplicator where to find it, by setting appropriate paths in batch files. Then you start the publication server and set up the details for your “master” database, and then do the same for the subscription server and the “client” database. Both are clever enough to translate between different database types, such as postgresql and mysql, which in some cases would be really handy.

My difficulty with both flavours of the package came when creating the “subscription”, ie telling the client database where to go find the master database. In neither case have I been able to sucessfully set this up, because of various errors. Weirdly, both flavours of the package give me an error in my log file about the first ever subscription that I tried to set up, despite having reinstalled, deleted everything I could find, and started from scratch several times.

The documentation in both cases hasn’t been good enough to resolve my issues, and neither have the forums. Actually, I’m still waiting on dbreplicator, which seems to be a little more active, so I should give them the benefit of the doubt for a couple of days.

I can see a great need for this kind of setup, assuming I can get around these initial teething troubles. So, my question is, has anyone successfully set up any of these packages on windows (sorry, but it needs to be windows at this stage), or does anyone know of any other packages I should try?

If I do manage to get things sorted I’ll post a detailed how-to…