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From Valentin Kulichenko <valentin.kuliche...@gmail.com>
Subject Re: TcpDiscoveryVmIpFinder's isShared property
Date Tue, 19 Jan 2016 00:52:22 GMT
Yakov,

JavaDoc is OK, but it seems to me that the confusion is caused by the fact
that setShared() method is placed on the IpFinderAdapter, while it actually
makes sense only for VmIpFinder. Can we deprecate it and always return
false from isShared() method for JDBC, S3 and others?

-Val

On Mon, Jan 18, 2016 at 1:56 AM, Yakov Zhdanov <yzhdanov@apache.org> wrote:

> Val, can you please review my changes to javadoc in master and update if
> necessary?
>
> --Yakov
>
> 2016-01-15 23:13 GMT+03:00 Andrey Kornev <andrewkornev@hotmail.com>:
>
>> It does now! Thank you!
>>
>> Andrey
>>
>> ------------------------------
>> Date: Fri, 15 Jan 2016 12:10:15 -0800
>> Subject: Re: TcpDiscoveryVmIpFinder's isShared property
>> From: valentin.kulichenko@gmail.com
>> To: user@ignite.apache.org
>>
>>
>> Andrey,
>>
>> Setting shared=true for TcpDiscoveryVmIpFinder means that nodes can
>> discover each other only within one JVM, when all nodes use the same
>> instance of IP finder. The shared "storage" in this case is just a local
>> collection. We use this heavily in unit tests, for example.
>>
>> TcpDiscoveryVmIpFinder with shared=false is how it's usually used. There
>> is no shared storage, so addresses have to be statically provided in the
>> configuration.
>>
>> shared=false for any other IP finder doesn't make any sense, because they
>> use some kind of storage by definition (e.g., JDBC or S3). This should be
>> clarified in docs.
>>
>> Makes sense?
>>
>> -Val
>>
>> On Fri, Jan 15, 2016 at 9:16 AM, Andrey Kornev <andrewkornev@hotmail.com>
>> wrote:
>>
>> Yakov,
>>
>> Thank you for the clarification, but I must admit I'm still not
>> completely out of the woods with respect to intended usage. Setting the
>> property to "false" seems to be most natural and only reasonable option,
>> and I wonder when would one want to set it to true? I must be missing
>> something.
>>
>> Also, just to clarify. In the last sentence you're saying: "This way user
>> doesn't have to list any IPs before start..." How would then the new nodes
>> know where to look for a node to connect to? They need to get the list of
>> seed nodes from somewhere, right? If so, then setting isShared to true
>> doesn't really make much difference - an initial list of seeds still must
>> be provided to every node.
>>
>> Thanks
>> Andrey
>>
>> ------------------------------
>> Date: Thu, 14 Jan 2016 12:55:52 +0300
>> Subject: Re: TcpDiscoveryVmIpFinder's isShared property
>> From: yzhdanov@apache.org
>> To: user@ignite.apache.org
>>
>>
>> Guys, this property is supported in VM IP finder for simplifying
>> discovery in single VM. I agree, that name could be better, but I would not
>> mess with it for now and just fix the javadocs (pls review, I did that in
>> master).
>>
>> "isShared" is a property of any IP finder. If it is "true" then IP finder
>> allows to add and remove addresses in runtime and this is how, for example,
>> S3 IP finder works. If "isShared" is "false" then IP finder is immutable
>> and all the addresses should be listed in configuration. This is the most
>> use case for VM IP finder. Since, usually VM IP finder is created per each
>> Ignite instance and all the known IPs are listed right away, but there is
>> also an option to make it shared - set "isShared" to true and literally
>> share it between local VM Ignite instances. This way user does not have to
>> list any IPs before start, instead all starting nodes add their addresses
>> to the finder, then get the registered addresses and continue with
>> discovery procedure.
>>
>> --Yakov
>>
>> 2016-01-13 22:45 GMT+03:00 Dmitriy Setrakyan <dsetrakyan@apache.org>:
>>
>> Any chance we could get an explanation here, so we can update the docs?
>> Yakov, I think you would know how this flag works.
>>
>> On Wed, Jan 13, 2016 at 11:40 AM, Vladimir Ozerov <vozerov@gridgain.com>
>> wrote:
>>
>> +1 to the question. Very confusing property. At the very least JavaDocs
>> should be reworked significantly.
>>
>> On Wed, Jan 13, 2016 at 8:32 PM, Andrey Kornev <andrewkornev@hotmail.com>
>> wrote:
>>
>> Hi there,
>>
>> I'm a bit confused about the purpose and usage of this property. What is
>> being shared with who? What are the consequences of setting the property to
>> true or false? Under what circumstances would one want to set it to either
>> true or false? Does one care at all?
>>
>> Thanks
>> Andrey
>>
>>
>>
>>
>>
>>
>

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