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
