Friday, August 24, 2012

Dream home projects

Home projects we dream(ed) about:
  • 4 season sun room
    • Had folks come out from Creative Energy  (here) to talk about a sun room .  
      • Wonderful products
      • Very good materials/engineering
      • Like the company
      • Cost way more than we are willing to pay
  • A sunny room (maybe with a pool) and retractable enclosure
    • Had a number of emails with someone from Libart (here)
      • Another GREAT product
      • Pretty good materials
      • Really like the company and attitudes
      • Cheaper than the sun room but the cost compared to benefits wasn't high enough.
  • Below-grade addition (1 or 2 story)
    • Really want to do it myself
    •  Concrete walls
      • Am thinking ICF might be the way to go
      • Also considered Superior Walls but they thought it might be pricey to use for an addition
      •  Reduce load on heat pump
      • sound deadening
    • Being "basement like", would need to somehow deal with excavating below existing foundation.  Looks possible but need to consult with someone more experienced.
  • "Screened" deck
    • Had a quote from a company for $5,000 for a pressure treated deck roughly 12x14 or so. 
    • Looking at building it myself now.
    • Result must be lower maintenance than our existing deck with looks like it was build in 1880 and not maintained.
    • Thinking about some (Brazillian?) hardwoods 
      • Importers
      • Expensive but given the right wood it could last 50+ years
      • Typically still requires an oil sealer to maintain the beautiful colors
      • Ipe was used on a number of high profile boardwalks
      • Some complaints about "sustainable" forests.  Most imports state that the forestry practices are sustainable now for their suppliers.  Not sure..
    • EzeBreeze windows
      • Here
      • Looks DIY friendly
    • Probably make concrete piers
    • This project should be in our budget and needs to get done soon one way or another.
  • Steel shingles (roofing)
    • various companies
    • Long warranties
    • Might be cost effective if I can install myself; some companies have training of some sort I think.
  • Greenhouse
  • Workshop
More to come..

Projects completed
  • Geothermal heat pump
    • Works great
    • Found a few companies/people worth their weight in diamonds
      • Delta Temp
        •  These guys are GREAT!  They fixed a VERY bad install; I wish I had started with them.
        • 804-739-5854
    • Learned a lot about bad contractors/companies and about how to evaluate better upfront
      • Town & Country mechanical - now defunct company from what I hear
      • Check that they have a license #
      • Check that they are licensed for a job of your size (i.e. Class A is better than C)
      • Check that their license isn't expired
      • Check with BBB
    • Learned that warranties are like statistics
      • lies and more lies
      • If warranty is through installer and installer goes out of business...no actual warranty exist

Thursday, August 23, 2012

OSGI to use or not to use

What are good reasons to move to an OSGI based infrastructure?
* It solves a real problem in your organization
* Your organization has the skills to support it
* Overall developer efficiency is either improved or not reduced compared to other gains
* Your application requires high availability which OSGI improves for some deployment cases
* Your infrastructure tends to support it

We have not done any prototyping with OSGI yet.  It has been on my "look into list" for a couple years now.  As I started looking into Apache ServiceMix I noted it probably is a good time to start researching more closely.

The number of books which discuss OSGI is increasing and the number of software products which either implement OSGI or work with it is increasing.  The alternative "module" system, project Jigsaw, sounds like it won't make it into Java 8 and may not cover some use cases (although I am not very knowledgeable on it).  If you have the money, maybe something like JRebel would be an alternative which helps with availability it seems.  Some recent new functionality in Apache Tomcat may improve availability as well but we have not tried it;  see the "Parallel deployment" Tomcat information here.

So far, our major need is the ability to minimize downtime especially for regular application updates which normally don't require DB changes.  Also, as we move more toward Web Services and messaging, I see a lot of potential for OSGI to help.  It should help enforce better structuring of code.  Although, if it is like many other things - what you get out is based on what you put in.  Some developers may not put the effort into using effectively.


Load balancing - Hardware or Software

Most of my load balancing experience is with F5 BigIP LTM.  This has served us well for a good number of years.  Recently I am left with a feeling that we should revisit this.  The hardware is getting older and is now showing signs of impending whole hog failure.  To top it off, the budget line items for replacements keep getting scratched off.

What are the options?
 Either more F5 equipment or maybe Citrix NetScaler or other hardware?
 On the other hand, we could go out on a limb with software load balancing.

What are the benefits of HW load balancing?
  1. Major features (of importance to us)
    1. SSL termination
    2. Load balancing
    3. Rewriting
    4. Caching
  2. Efficiency
  3. Ease of use
    1. TCL used for language
    2. Single point of SSL certificate management
  4. Support
    1. Nice to have someone you can call 
What are the downsides of HW load balancing?
  1. Cost
  2. (near) single point of failure (unless item 1 is not an issue for you)
  3. Limited features

What are potential benefits of SW load balancing?
  1. Potentially lower cost
  2. Potentially less of a "single point of failure"
  3. Handle high loads (notes below)
  4. More features available
  5. Flexibility 
There are downsides to SW load balancing.
  1. More challenging integration (potentially multiple products used to implement feature sets)
  2. Requires more in house expertise
  3. Others - work in progress
Software Options
  1. nginx
    1. http://nginx.org/
  2. lighttpd
    1. http://www.lighttpd.net/
  3. Apache Server
    1. http://httpd.apache.org/docs/2.2/mod/mod_proxy_balancer.html
  4. Apache Traffic Server
    1. http://trafficserver.apache.org/
  5. Squid
    1. http://www.squid-cache.org/
Need to include some supporting information sites.  Would be good to do some proof of concepts implementations and some performance benchmarking.