Well I can do that, but I would probably recommend using connectionTimeout
= sessionTimeout.
By default Curator uses:
private static final int DEFAULT_SESSION_TIMEOUT_MS =
Integer.getInteger("curator-default-session-timeout", 60 * 1000);
private static final int DEFAULT_CONNECTION_TIMEOUT_MS =
Integer.getInteger("curator-default-connection-timeout", 15 * 1000);
So by default Curator will only check the first node.
I can't think of a use case where that's useful.
Regardless I can write something after I do more tests on this.
On Wed, Nov 2, 2016 at 9:10 AM, Jordan Zimmerman <[email protected]
> wrote:
> That’s correct Benjamin. As Curator wraps the library-provided ZooKeeper
> class there’s nothing Curator can do about this. I’ll try to write a Tech
> Note about this when I can. If you don’t mind, Benjamin, maybe you could
> write it?
>
> https://cwiki.apache.org/confluence/display/CURATOR/Tech+Notes
>
> -Jordan
>
>
> On Nov 2, 2016, at 11:08 AM, Benjamin Jaton <[email protected]>
> wrote:
>
>
> In your example (conenctionTimeout = 10, sessionTimeout = 60, 3 nodes), if
>>> the first node that gets picked up is down it will timeout after 20 sec. So
>>> Curator would fail to connect yet the ensemble is available.
>>
>>
>> How can this timeout after 20 secs, if the connection timeout is 10
>> seconds? Also,
>>
>
> Curator's connectionTimeout is to be understood as connection to the whole
> ensemble, not individual node.
>
> How long do you think the ZooKeeper API will wait for a connection before
> trying the next node?
> The answer is sessionTimeout / #nodes = 60 / 3 = 20 seconds.
>
> 0 sec - try 1st node
> 20 sec - try 2nd node
> 40 sec - try 3rd node
>
> Now if Curator has a cap at 10 seconds, it won't wait for the ZK API to
> reach the other 2 nodes.
>
> Hope that's clearer.
>
> Benjamin
>
>
>>
>> So Curator would fail to connect yet the ensemble is available
>>
>>
>> Can you explain the above statement then? As for my understanding,
>> curator will try all Zookeeper nodes until it connects to an up and running
>> zookeeper server or until the connection timeout.
>>
>> -Imesha
>>
>> On 2 November 2016 at 10:45, Cameron McKenzie <[email protected]>
>> wrote:
>>
>>> Session timeout is a Zookeeper concept. It's just the amount of time (in
>>> MS) that a client session can be idle for before the Zookeeper server times
>>> it out. A heart beat keeps the session alive, so the session will only
>>> time out due to network issues.
>>>
>>> The connection timeout is a Curator concept. Jordan described its use in
>>> this thread. Basically, it just defines how long Curator will wait for a
>>> connection to be established to Zookeeper before giving up and trying again.
>>>
>>> On Wed, Nov 2, 2016 at 4:00 PM, Imesha Sudasingha <
>>> [email protected]> wrote:
>>>
>>>> Hello all,
>>>>
>>>> I was going through this thread and found out I too need a clear
>>>> explanation on "what is connectionTimeout and sessionTimeout". Even though
>>>> you have discussed a lot about it(which I have read), still I'm not getting
>>>> a clear picture. Can someone elaborate on the it? And give a clear view of
>>>> those 2 parameters and what they are for?
>>>>
>>>> Thanks!
>>>>
>>>> Regards,
>>>> Imesha Sudasingha
>>>>
>>>> On Nov 2, 2016 4:26 AM, "Jordan Zimmerman" <[email protected]>
>>>> wrote:
>>>>
>>>>>
>>>>> so if we use a connectionTimeout smaller than sessionTimeout, we may
>>>>> fail before having tried all the nodes.
>>>>>
>>>>>
>>>>> That’s correct and up to you. That’s why these are configurable
>>>>> options. Use values that make sense for your applications.
>>>>>
>>>>> -Jordan
>>>>>
>>>>>
>>>>>
>>>>>
>>>
>>
>>
>> --
>> *Imesha Sudasingha*
>> Undergraduate of Department of Computer Science and Engineering,
>> University of Moratuwa.
>> +94717086160
>> View in Linkedin <https://lk.linkedin.com/in/imeshasudasingha>
>>
>
>
>
