Cassandra

Cassandra#

Just some free format stuff for a small studying / experiment with NoSQL stuff.

Table of Contents

Resources#

Install/config#

lxc#

auto eth0
#iface eth0 inet dhcp
iface eth0 inet static
        address 10.0.4.10
        netmask 255.255.255.0
        network 10.0.4.0
        broadcast 10.0.4.255
        gateway 10.0.4.1
        post-up route add default gw 10.0.4.1 dev eth0
        # dns-* options are implemented by the resolvconf package, if installed
        dns-nameservers 213.197.28.3 213.197.30.28
        dns-search computerhok.nl

cassandra#

cssndra@ubuntu1:/opt/cassandra$ ls -l
total 248
-rw-r--r-- 1 cssndra cssndra 152928 Apr  8 19:21 CHANGES.txt
-rw-r--r-- 1 cssndra cssndra  11609 Apr  8 19:21 LICENSE.txt
-rw-r--r-- 1 cssndra cssndra  47580 Apr  8 19:21 NEWS.txt
-rw-r--r-- 1 cssndra cssndra   1820 Apr  8 19:21 NOTICE.txt
-rw-r--r-- 1 cssndra cssndra   3569 Apr  8 19:21 README.txt
drwxr-xr-x 2 cssndra cssndra   4096 May 15 21:43 bin
drwxr-xr-x 2 cssndra cssndra   4096 May 15 21:43 conf
drwxr-xr-x 2 cssndra cssndra   4096 May 15 21:43 interface
drwxr-xr-x 4 cssndra cssndra   4096 May 15 21:43 javadoc
drwxr-xr-x 3 cssndra cssndra   4096 May 15 21:43 lib
drwxr-xr-x 3 cssndra cssndra   4096 May 15 21:43 pylib
drwxr-xr-x 4 cssndra cssndra   4096 Apr  8 19:21 tools
cssndra@ubuntu1:/opt/cassandra$ ./bin/cassandra-cli Connected to: "Test Cluster" on 127.0.0.1/9160 Welcome to Cassandra CLI version 1.2.4 Type 'help;' or '?' for help. Type 'quit;' or 'exit;' to quit. [default@unknown] create keyspace DEMO with placement_strategy = 'org.apache.cassandra.locator.SimpleStrategy' and strategy_options = {replication_factor:1}; f243abc2-57dc-32b4-9390-beac4e988c5b [default@unknown] use DEMO; Authenticated to keyspace: DEMO [default@DEMO] create column family Users with key_validation_class = 'UTF8Type' and comparator = 'UTF8Type' and default_validation_class = 'UTF8Type'; bb07d315-a824-3bbb-9b48-d759288e57b4 [default@DEMO] set Users[1234][name] = scott; Value inserted. Elapsed time: 63 msec(s). [default@DEMO] set Users[1234][password] = tiger; Value inserted. Elapsed time: 3.96 msec(s). [default@DEMO] get Users[1234]; => (column=name, value=scott, timestamp=1368679313136000) => (column=password, value=tiger, timestamp=1368679322745000) Returned 2 results. Elapsed time: 58 msec(s). [default@DEMO]

Now on the second node (ubuntu2) start the node with /opt/cassandra/bin/cassandra , and start creating the cluster. First create the proper tokens for a 4 node cluster, by using the following py : 

# Number of nodes in the cluster
num_node = 4

for n in range(num_node):
    print int(2**127 / num_node * n)
And execute it : 
cssndra@ubuntu1:~$ python calcToken.py 
0
42535295865117307932921825928971026432
85070591730234615865843651857942052864
127605887595351923798765477786913079296

First startup cassandra on all 4 nodes by executing from the host: ssh ubuntu@10.0.4.11 'sudo su - cssndra /opt/cassandra/bin/cassandra'

Cluster config#

IPDCRACKseeder
10.0.4.11DC1RAC1Y
10.0.4.12DC1RAC2N
10.0.4.13DC2RAC1Y
10.0.4.14DC2RAC2N

Creating keyspace, tables, inserting, updating , querying#

Create keyspace#

First create a keyspace. You can do that both with cassandra-cli and cqlsh, but they have different syntaxes :-) .
Here's a cqlsh example: 

[default@unknown] cssndra@ubuntu1:~$ cqlsh 
Connected to Test Cluster at localhost:9160.
[cqlsh 2.3.0 | Cassandra 1.2.4 | CQL spec 3.0.0 | Thrift protocol 19.35.0]
Use HELP for help.
cqlsh> CREATE KEYSPACE demo_keyspace WITH REPLICATION = { 'class' : 'NetworkTopologyStrategy', 'DC1' : 2, 'DC2' : 2};
cqlsh> select * from system.schema_keyspaces;

 keyspace_name | durable_writes | strategy_class                                       | strategy_options
---------------+----------------+------------------------------------------------------+----------------------------
   system_auth |           True |          org.apache.cassandra.locator.SimpleStrategy | {"replication_factor":"1"}
 demo_keyspace |           True | org.apache.cassandra.locator.NetworkTopologyStrategy |      {"DC2":"2","DC1":"2"}
        system |           True |           org.apache.cassandra.locator.LocalStrategy |                         {}
 system_traces |           True |          org.apache.cassandra.locator.SimpleStrategy | {"replication_factor":"1"}

cqlsh>

Create a column family#

Create a columnfamily with the cassandra-cli utility: 

cssndra@ubuntu1:~$ cassandra-cli
Connected to: "Test Cluster" on 127.0.0.1/9160
Welcome to Cassandra CLI version 1.2.4

Type 'help;' or '?' for help.
Type 'quit;' or 'exit;' to quit.

[default@unknown] use demo_keyspace;
Authenticated to keyspace: demo_keyspace
[default@demo_keyspace] create column family users with key_validation_class = 'UTF8Type' and comparator = 'UTF8Type' and default_validation_class = 'UTF8Type';
0b6b0010-fc89-35a1-ad05-77d53e5a4443

Insert data#

Again with the cassandra-cli utility insert some data in the users columnfamily: 

[default@demo_keyspace] cssndra@ubuntu1:~$ cassandra-cli
Connected to: "Test Cluster" on 127.0.0.1/9160
Welcome to Cassandra CLI version 1.2.4

Type 'help;' or '?' for help.
Type 'quit;' or 'exit;' to quit.

[default@unknown] use demo_keyspace;
Authenticated to keyspace: demo_keyspace
[default@demo_keyspace] set users[1234][name] = scott;
Value inserted.
Elapsed time: 52 msec(s).
[default@demo_keyspace] set users[1234][password] = scott-secret;
Value inserted.
Elapsed time: 14 msec(s).
[default@demo_keyspace] set users[1234][length] = 185;
Value inserted.
Elapsed time: 8.76 msec(s).
[default@demo_keyspace] set users[1235][name] = harry;
Value inserted.
Elapsed time: 6.71 msec(s).
[default@demo_keyspace] set users[1235][length] = 181;
Value inserted.
Elapsed time: 13 msec(s).
[default@demo_keyspace] set users[1235][whatevercolumn] = skfkjdkfjdklsjfsjflkjldk181;
Value inserted.
Elapsed time: 6.2 msec(s).
[default@demo_keyspace] list users;
Using default limit of 100
Using default column limit of 100
-------------------
RowKey: 1234
=> (column=length, value=185, timestamp=1368883341707000)
=> (column=name, value=scott, timestamp=1368883316118000)
=> (column=password, value=scott-secret, timestamp=1368883330142000)
-------------------
RowKey: 1235
=> (column=length, value=181, timestamp=1368883368497000)
=> (column=name, value=harry, timestamp=1368883358461000)
=> (column=whatevercolumn, value=skfkjdkfjdklsjfsjflkjldk181, timestamp=1368883385475000)

2 Rows Returned.
Elapsed time: 42 msec(s).

And insert with the cqlsh -2 utility : 

cssndra@ubuntu1:~$ cqlsh -2
Connected to Test Cluster at localhost:9160.
[cqlsh 2.3.0 | Cassandra 0.0.0 | CQL spec 2.0.0 | Thrift protocol 19.35.0]
Use HELP for help.
cqlsh> USE demo_keyspace ;
cqlsh:demo_keyspace> INSERT INTO users ( key, name, password, whatevercolumn) VALUES ( '12345' , 'harry' , 'wachtwoordje' , 'blablabla fjkdsjf l4j 2k43u');
cqlsh:demo_keyspace>

And a stupid shell script to insert bulk data : 

#!/bin/bash
#
num=$1
let n=0
TMPFILE=/tmp/$RANDOM.cql
echo "use demo_keyspace;" > $TMPFILE
while [ $n -lt $num ]
do
 # echo $n
 CQL="INSERT INTO users ( key, name, password, whatevercolumn) VALUES ( '99${n}' , 'harry${n}' , 'wachtwoordje${n}' , 'blablabla fjkdsjf ${n} ${n} ${n}2k43u');"  
 echo $CQL >> $TMPFILE
 let n=n+1
done

echo "echoing inserts to cqlsh..."
cqlsh -2 -f $TMPFILE 

echo "listing users..."
cat <<EOF | cassandra-cli
 use demo_keyspace;
 list users;
EOF
rm $TMPFILE

Cassandra notes/questions#

Questions#

Notes#