Friday, March 07, 2003

RSS for comments and ids

I got Sam's comment feed - and it imediately broke my agregator. The problem is quite simple - I use the link of the item as a key, and in the comment feed all
comments use the same key as the article. And the same title.

This changes the entire data model - for each link I'll have to store a list of MD5s, and treat it as a multi-value. The first time ( if no MD5 is found ) it'll be the "source" message, and all other occurances - including edits of the original - can be treated as "Re: " - to implement the threading in the mail reader.

Probably I'll just go for the simplest solution - and keep a .db keyed by MD5 (that should be unique enough ) - the whole idea is to avoid sending the same item multiple times.

Once again - the RSS proves to be almost completely useless.

Update: Sam changed the links. There are few problems. Some of his links are quite strange .../blog/('1247.html#c1047152121',), I suppose a small bug sneaked in.

Worse - I now lost the way to relate comments with postings. I'll have to parse the generated links and remove the ending to guess the original posting. Sam - please change back, I fixed my code to deal with the old problem and I think the workaround for the new problems is harder :-)

A better solution would be to just add a separate tag with the comment id. Of couse, that would be in the RSS-2003-03-08 "standard", and nobody else will use the same tag name. ( we should use the date of the "standard du jour")

Outlook mail aggregator

It seems there are other people who preffer the mail reader - NewsGator is specific to Outlook, so I won't pay them $29.

mail aggregator code

I cleaned up a bit and uploaded my mail aggregator. Getting rid of the pickle was a great move - db seems good enough.

For now I use simple name-value mappings and several db files - it's easier to debug and get other tools to use the same data. I was thinking of a real database - but that would make it more complex and I doubt it'll scale or work better.

I doubt too many people will find it usefull - when they have all the fine 3-panel graphical agreggators. I just use it to read weblogs in train, using my old "pine" and sometimes mozilla/evolution/kmail ( when I feel a need for real nice GUI - and go back to pine when I want to read mail ).

HelloWorld - finally !

Last night I got the first "hello world" page from tomcat5/JMX. No server.xml, no fat, only a small set of mbeans driven by ant. Things were very close for a while but never quite work completely. There is still a lot of work, mostly downhill IMO.

I can't wait to finish - I'm in overload mode for some time, doing too many things at once.

Saturday, March 01, 2003

JMX clustering

I don't like session clustering for a lot of reasons. Clustering in general is great - but the servlet session API just doesn't have enough power to allow a correct and efficient use of clustering. The use case for caching some values is compromised,

there is no transaction support, no feedback or control - users are much better served by assuming the session is transient, and using database or user-controled clustering.

By clustering I understand broadcasting and mirroring some data on multiple instances - there are many other meanings. It is a very powerful tool if used right.

There is one use of clustering that would be extremely intersting - broadcasting and clustering the JMX attributes. The idea is to have a global view - each tomcat instance could brodacast its mbeans and attributes, and may be able to take more inteligent decisions knowing the state of the other instances. And the admin console would get info from all instances.