Computación Distribuida

Tutoriales de cómo montarla:

Official Package To Install On Debian

Installing DataStax Community on Debian-based systems

Es necesario descargar Cassandra Cluster Manager SUBIDO EN GITHUB

Requirements 

Hemos descargado los más recientes de todo

A working python installation (tested to work with python 2.7).

pyYAML (http://pyyaml.org/ descarga y descomprime y te vas a la carpeta de descompresión -- sudo easy_install pyYaml)

o bien sudo python setup.py install 

six (https://pypi.python.org/pypi/six descarga y descomprime y te vas a la carpeta de descompresión -- sudo easy_install six)

o bien sudo python setup.py install (no, no es un error)

ant (http://ant.apache.org/, on Mac OS X, brew install ant)

psutil (https://pypi.python.org/pypi/psutil)

Java (which version depends on the version of Cassandra you plan to use. If unsure, use Java 7 as it is known to work with current versions of Cassandra).

Problemas: easy_install no es un comando válido, en askubuntu dan esta solución:

sudo apt-get update sudo apt-get upgrade sudo apt-get install python-setuptools

Después de todo esto ya podemos usar el CCM:

Installation

ccm uses python distutils so from the source directory run:

sudo ./setup.py install

Usage

Let's say you wanted to fire up a 3 node Cassandra cluster.

Short version

ccm create test -v 2.0.5 -n 3 -s

You will of course want to replace 2.0.5 by whichever version of Cassandra you want to test.

El 3 marca que se estám creando 3 nodos en el cluster (comprobar que es esa versión de Cassandra la que tenemos instalada)

Para mejor entendimiento de lo que se hace y configurar personalmente las opciones mejor seguir la versión larga:

Longer version

ccm works from a Cassandra source tree (not the jars). There are two ways to tell ccm how to find the sources:

If you have downloaded and compiled Cassandra sources, you can ask ccm to use those by initiating a new cluster with:

ccm create test --install-dir=<path/to/cassandra-sources>

or, from that source tree directory, simply

ccm create test

You can ask ccm to use a released version of Cassandra. For instance to use Cassandra 2.0.5, run

ccm create test -v 2.0.5

ccm will download the source (from http://archive.apache.org/dist/cassandra), compile it, and set the new cluster to use it. This means that this command can take a few minutes the first time you create a cluster for a given version. ccm saves the compiled source in ~/.ccm/repository/, so creating a cluster for that version will be much faster the second time you run it (note however that if you create a lot of clusters with different versions, this will take up disk space).

Once the cluster is created, you can populate it (with 3 nodes) and start all the nodes with:

ccm populate -n 3 ccm start

That will start 3 nodes on IP 127.0.0.[1, 2, 3] on port 9160 for thrift, port 7000 for the internal cluster communication and ports 7100, 7200 and 7300 for JMX. You can check that the cluster is correctly set up with

ccm node1 ring

You can then bootstrap a 4th node with

ccm add node4 -i 127.0.0.4 -j 7400 -b

(populate is just a shortcut for adding multiple nodes initially)

ccm provides a number of conveniences, like flushing all of the nodes of the cluster:

ccm flush

or only one node:

ccm node2 flush

You can also easily look at the log file of a given node with:

ccm node1 showlog

Finally, you can get rid of the whole cluster (which will stop the node and remove all the data) with

ccm remove

The list of other provided commands is available through

ccm

Multi-node Cluster

Bulk-data load

Setup por Dani, es necesario tener la aceleración virtual (VT-x) activada para que funcione, en caso de no tenerla se puede activar a través de las BIOS, en Windows, para llegar a la BIOS nada más encender el ordenador pulsa DEL o F2 8antes de llegar al login de usuario).

La máquina es un Debian normal (64 bits) con Cassandra instalado, podemos tener las dos consolas igual que antes, la consola normal de Debian como la de root y la de CQL simplemente usando el commando.

cqlsh

Hemos descargado el driver a Window y lo hemos subido Cassandra a través del cofmando curl con el programa HFS. 

Es necesarrio tener en el classpath un log para java. Esto lo sabemos por los warnings que nos han saltado. Hay que añadir log.properties

Warnings:

"WARN no appenders could be found for logger (com.datastax.driver.core.Cluster)

WARN Please initialize the log4j system properly

Problema surgido mientras intentamos seguir el tutorial: Getting Started with Apache Cassandra and Java (Part I)

Problema: ¿Cómo compilar y correr una aplicaión de Java?

En clase el jueves pasado: Compilamos con Eclipse y con HFS hemos conseguido que el archivo .class apareciese en Cassandra pero el comando de correr el código daba error, subimos un .jar en su lugar pero tampoco conseguimos que funcionase. (Eclipse no corría el programa, saltaba error)

Ahora: intentamos subir el .java a Cassandra así como el driver de java necesario y correr el commando de compilación, mensaje de error:

 bash: javac: command not found 

¿Es que no es Cassandra quien tiene que compilar y correr el código? Entonces, ¿cómo y dónde se corre el código?

C*ollege Credit: Creating Your First App in Java with Cassandra and in video

First we download the HFS.exe. It's a program that creates a server to which we will upload data and connect from Cassandra:

To connect from Cassandra we use the next command in the root console (alt+F2)

source: http://planetcassandra.org/getting-started-with-apache-cassandra-and-java/

You need to download this driver.

Consola de VMware_ ALT + F2 para poder escribir

para  poder trabajar en java, sompilaremos las clases en nuestra cuenta de linux, en VMware ponemos:

ALTER TABLE videos WITH compression = { 'sstable_compres

sion' : '' };

Lets take a look at the health of your instance. From the command prompt in the root console, type:

  # nodetool status

  From here we can see that the instance (node) is up and in a normal running state. Because it is not part of a cluster, it effectively owns 100% of the data.

If we type:

  # nodetool info

  We get more indepth information on the configuration of the node, including uptime, heap size, and gossip and thrift activity. Using nodetool tpstats (below) displays the number of active, pending and completed tasks for each of the thread pools that Cassandra uses for each stage of operation.

3 archivos principales de configuración:

Lets take a look at the three main configuration files for Apache Cassandra. To view the configuration files, from the root console type the following:

# cd /etc/cassandra

# ls 

Now we will look at each in more detail

cassandra.yaml

cassandra-env.sh

log4j-server.properties

The cassandra.yaml file is the main configuration file for Cassandra. After changing properties in this file, you must restart your instance for the changes to take effect. In this file, you can find properties to tune performance and system resource utilization (memory, disk I/O, CPU, etc.) for reads and writes. It also contains node and cluster initialization properties.

The cassandra-env.sh file in part controls the environment settings for Cassandra. It has heap sizing options(MAX_HEAP_SIZE, HEAP_NEWSIZE) and JMX options which can be monitored or manipulated, like nodetool, an JMX-compliment management tool. By default, JMX listens on port 7199 without authentication.

 If you are interested in configuring logging, you should look at the the log4j-server.properties file. In some situations, the output from nodetool utility is not enough to diagnose an issue. If you find that you need more information on runtime behavior of your instance, you can increase the logging levels to get more diagnostic information on specific portions of the system.

Podemos ver la información de cada archivo en la consola de root con el comando:

 # more cassandra.yaml

y podemos cambiarlos en un editor de texto.

para más información en los archivos de configuración:

http://wiki.apache.org/cassandra/StorageConfiguration

Ejemplo:

"Where are my keyspaces?"

LiveSchemaUpdates. You can load the schema once by using: