thx mahadev :-)

On Thu, Mar 4, 2010 at 4:05 AM, Mahadev Konar <maha...@yahoo-inc.com> wrote:

> Hi Qian,
>  I am not sure if I did respond to your email or not. Sorry, too many
> emails
> I am catching up on. You are right that if you specify just a single host
> then the client would not be able to switch to another server. There have
> been some ideas around Dynamic configuration and storing zookeeper ensemble
> information on the zookeeper cluster itself.
>
> http://issues.apache.org/jira/browse/ZOOKEEPER-338
> http://issues.apache.org/jira/browse/ZOOKEEPER-107
> http://issues.apache.org/jira/browse/ZOOKEEPER-390
>
> This might answer some of the problems you mention, but they are all being
> worked upon!
>
> Thanks
> mahadev
>
>
> On 3/1/10 6:09 PM, "Qian Ye" <yeqian....@gmail.com> wrote:
>
> > Thanks Mahadev, I see what you mean.
> >
> > Here is another question, the client need a list of Zookeeper servers to
> > initialize the handler, and there is no API for the client to get
> awareness
> > of all the Zookeeper servers in one cluster. That means, if I only
> provide
> > one Zookeeper server in the client's host list, the client would not
> switch
> > to another available Zookeeper server, when the given one was failed. I
> > think is strategy is flawed. The client should be able to find out all
> the
> > Zookeeper servers in the cluster. Is there any compromise for this issue?
> >
> > thanks
> >
> > On Tue, Mar 2, 2010 at 7:29 AM, Mahadev Konar <maha...@yahoo-inc.com>
> wrote:
> >
> >> HI Qian,
> >> You are right we do have any way of handling clients dynamically so that
> >> every server has balanced load. This requires a careful design since we
> >> would not want client connections to keep flipping around and also
> maintain
> >> stability as much as we can. We have had some discussions about it but
> >> nothing concrete has materialized yet.
> >>
> >> We do have checks in place that prevent more than a certain number of
> >> connections (default 10) from the same ip address. This is to keep too
> many
> >> zookeeper client instances from the same client bogging down the
> zookeeper
> >> service. Also, we have throttling for number of outstanding requests
> from
> >> clients (currently set to 1000 by default). This allows zookeeper
> service
> >> to
> >> throttle zookeeper clients. This throttling isnt done on per client
> basis
> >> but is just a check to not bring down the zookeeper service because of
> some
> >> misbehaved client.
> >> Any other checks that you specifically were thinking of?
> >>
> >> Thanks
> >> mahadev
> >>
> >> On 2/28/10 10:18 PM, "Qian Ye" <yeqian....@gmail.com> wrote:
> >>
> >>> Hi guys:
> >>>
> >>> As I know, when a client connected to Zookeeper servers, it would
> choose
> >> a
> >>> server randomly (without the zoo_deterministic_conn_odrder on), and
> then,
> >>> the client would talk to the server until a failure happened. It seems
> >> that
> >>> zookeeper server cannot handle the client connection dynamically
> >> according
> >>> to the load of the server. If some flaw of a client made the client
> >> connect
> >>> Zookeeper servers frequently, it may prevent other normal clients from
> >>> getting services from Zookeeper, right? So, is there any method to
> >> resolve
> >>> these two practical problems:
> >>>
> >>> 1. Handle and apportion clients dynamically, so every servers would
> have
> >>> balanced load.
> >>> 2. Some of frequency controller, which set a frequency threshold on the
> >>> frequency of requests from a client, prevent server resource from being
> >>> exhausted by a few clients.
> >>>
> >>> --
> >>> With Regards!
> >>>
> >>> Ye, Qian
> >>
> >>
> >
>
>


-- 
With Regards!

Ye, Qian

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