Interesting Tech Book list (would keep growing as the reading continues!)

1. A note of Distributed Computing - Waldo et. al
2. Six Misconceptions about Reliable Distributed Computing - Werner Vogels
3. Convenience over Correctness - Steve Vinoski

Gold and its role in the economy / Misunderstanding

http://finance.yahoo.com/news/gold-rallied-years-misunderstanding-021935344.html

Bill Gates - On 60 minutes

http://www.engadget.com/2013/05/13/bill-gates-60-minutes/

Third gird science project links

http://www.education.com/activity/third-grade/science/?page=1

Approaching Math

Groovy issues / things to learn - Keys of a map containing variable values

We are into developing groovy scripts these days and I have pondered about how to make the key a variable and today, I have come across a use case and a way to do this.

If you have a Map of [name : value], the name here itself is a literal, but if you would like the name to be a variable, you would have to enclose it within a paranthesis. For instance, this map would become [(name) : value]. Let us day, if we have defined name as

def name = "test", the output of the map will be {"test" : value}, instead of {name: value}. Here since the name is enclosed within a paranthesis, essentially it acts like a bind variable and replaces the derived value of "name", which turns out to be "test" in this case.

Cassandra

Here are some of the Cassandra terminologies:

1. Keyspaces are similar to schemas/databases.
Here is an example of how to create a keyspace.


create keyspace endpoint_scripts
with placement_strategy = 'org.apache.cassandra.locator.NetworkTopologyStrategy'
and strategy_options=[{eu-west:3, us-east:3}];


2. Column families are similar to tables.


create column family scripts
with comparator = 'UTF8Type'
and key_validation_class = 'UTF8Type'
and default_validation_class = 'BytesType'
and column_metadata=[
{column_name: uri, validation_class: UTF8Type, index_type: 0},
{column_name: revision, validation_class: LongType, index_type: 0},
{column_name: active, validation_class: BooleanType, index_type: 0},
{column_name: user_authentication_required, validation_class: BooleanType, index_type: 0},
{column_name: creation_date, validation_class: DateType, index_type: 0}
]
and rows_cached = 10000
and row_cache_provider = SerializingCacheProvider
and keys_cached = 1.0
and memtable_flush_after = 120
and memtable_operations = 2
and memtable_throughput = 256
and read_repair_chance = 0.0;