Apache drill High availability

[pujari Satish <sa...@gmail.com>]

Hi Team,

Good Morning. I am trying to do drill high avilability using Haproxy load
balancer.
Is drill supports for high availability ?


please let me know in this.


-Thanks,
Satish

Re: Apache drill High availability

[Hanumath Rao Maduri <ha...@gmail.com>]

Unlike other databases or data engines drill doesn't store data in its own
storage engine. So high availability of the data when using Drill means the
storage engine needs to support high availability.

High availability can also mean that when running a query even though some
of the fragments/ nodes might fail, query needs to succeed. In this
scenario Drill reports an error to the user and expects the user to re-run
the query. On re-running the query again, it might be successful (of-course
depending upon load of the system).

If a node is crashed or not responding then the ZK will not consider the
node during planning stage itself. Hence, no fragments are executed on the
node (and query performance might degrade in this scenario).

Thanks,


On Tue, Aug 28, 2018 at 9:34 AM salim achouche <sa...@gmail.com> wrote:

> You need to clarify your definition of HA as there can be multiple faults
> at play:
> - A Drill cluster can handle nodes going down (and new ones joining the
> cluster)
> - Though, running queries (which are executed in a distributed manner)
> might fail if they had minor-fragments running on a faulty node
> - Similarly, Drill has some built-in resilience to network disconnects
> albeit it is not always transparent (I believe, queries might fail if
> network disconnect happened during a connection exchange)
>
> Regards,
>
> On Mon, Aug 27, 2018 at 10:48 PM pujari Satish <sa...@gmail.com>
> wrote:
>
> > Hi Team,
> >
> > Good Morning. I am trying to do drill high avilability using Haproxy load
> > balancer.
> > Is drill supports for high availability ?
> >
> >
> > please let me know in this.
> >
> >
> > -Thanks,
> > Satish
> >
>

Re: Apache drill High availability

[salim achouche <sa...@gmail.com>]

You need to clarify your definition of HA as there can be multiple faults
at play:
- A Drill cluster can handle nodes going down (and new ones joining the
cluster)
- Though, running queries (which are executed in a distributed manner)
might fail if they had minor-fragments running on a faulty node
- Similarly, Drill has some built-in resilience to network disconnects
albeit it is not always transparent (I believe, queries might fail if
network disconnect happened during a connection exchange)

Regards,

On Mon, Aug 27, 2018 at 10:48 PM pujari Satish <sa...@gmail.com>
wrote:

> Hi Team,
>
> Good Morning. I am trying to do drill high avilability using Haproxy load
> balancer.
> Is drill supports for high availability ?
>
>
> please let me know in this.
>
>
> -Thanks,
> Satish
>