Some questions about Zookeeper and how it connects to NoSQL database.

[Tuan Luu <tu...@aptos.in>]

Dear,

I'm new to Zookeeper and I'm still not sure how it works with database
system.

Thus I have some questions and I hope you can help me with them.

1. Is every server in Zookeeper system also have a copy of database? So
every time a server starts, if will connect to database and download
everything to its local memory?Or each server in Zookeeper system is also a
database itself?

2. What would happen if size of database is bigger then disk size of
Zookeeper server?

3. Is it possible for me to connect Zookeeper system to my NoSQL Cassandra
database? I really don't understand how the system will work! When a read
request comes, what is the execution flow between Zookeeper and Cassandra
database?

Thank you very much.

*Kind Regards,*

*Tuan, Luu Dinh*

Re: Some questions about Zookeeper and how it connects to NoSQL database.

[n keywal <nk...@gmail.com>]

Hi,

Your question would likely be better suited in the Cassandra mailing list.

In a few words: you can, in a way, consider ZooKeeper as a database, as it
persists data. But the features used are mostly the synchronisation
services to manage the cluster state. So the question to your first
question is 'no', so the issue mentioned in the second does not occur in
practise.

You can have a look at the Google paper on Big Table, it explains its role
in a typical BigTable implementation.

Nicolas

On Tue, Sep 18, 2012 at 12:14 PM, Tuan Luu <tu...@aptos.in> wrote:

> Dear,
>
> I'm new to Zookeeper and I'm still not sure how it works with database
> system.
>
> Thus I have some questions and I hope you can help me with them.
>
> 1. Is every server in Zookeeper system also have a copy of database? So
> every time a server starts, if will connect to database and download
> everything to its local memory?Or each server in Zookeeper system is also a
> database itself?
>
> 2. What would happen if size of database is bigger then disk size of
> Zookeeper server?
>
> 3. Is it possible for me to connect Zookeeper system to my NoSQL Cassandra
> database? I really don't understand how the system will work! When a read
> request comes, what is the execution flow between Zookeeper and Cassandra
> database?
>
> Thank you very much.
>
> *Kind Regards,*
>
> *Tuan, Luu Dinh*
>