Databases Reference
In-Depth Information
database is very fast and tries to do most operations in memory. However, this also means it shares
the limitations of Redis when it comes to having a big divergence between the working set in
memory and the entire data set on disk.
Alchemy achieves impressive performance because:
It uses an event-driven network server that leverages memory as much as possible.
Effi cient data structures and compression help store a lot of data effi ciently in RAM.
➤
➤
The most relevant SQL statements for OLTP are supported, keeping the system
lightweight and still useful. Every complex SQL statement is not supported. The list
of supported SQL commands is available online at
http://code.google.com/p/
alchemydatabase/wiki/CommandReference#Supported_SQL
.
➤
WEBDIS
Webdis (
http://webd.is
) is a fast HTTP interface for Redis. It's a simple HTTP web server that
sends requests down to Redis and sends responses back to the client. By default, Webdis supports
JSON but it also supports other formats, which are as follows:
Text, served as text/plain
➤
HTML, XML, PNG, JPEG, PDF served with their extensions
BSON, served as application/bson
➤
➤
Raw Redis protocol format
Webdis acts like a regular web server, but of course with a few modifi cations it supports all those
commands that Redis can respond to. Regular requests are responded to with a 200 ok code. If
access control doesn't allow a response to a request, the client receives a 403 forbidden HTTP
response.
GET
,
POST
, and
OPTIONS
are not allowed and so return 405 Method Not Allowed. Webdis
supports HTTP
PUT
and value can be set with a command as follows:
➤
curl --upload-file my-data.bin http://127.0.0.1:7379/SET/akey
SUMMARY
As I write the summary to this last chapter, I hope you had an enjoyable and enriching experience
learning the details of an emerging and important technology. This chapter presents a few use cases,
tools, and utilities that relate to NoSQL.
Tools like RRDTool and Nagios are general purpose and are valuable additions to any monitoring
and management software. Tools like nodetool add value when it comes to specifi cally managing and
monitoring Cassandra.
Scribe, Flume, and Chukwa provide powerful capabilities around distributed log processing and
aggregation. They provide a very robust function to help manage the large number of log fi les that
