[infinispan-dev] Issue with JGroups config files in ispn-core

[Tristan Tarrant]

Let me add:

specifying a configuration file just by name is NOT enough. We also need 
to allow users to specify an InputStream which IMHO is the "only correct 
way" :)

Tristan

On 13/06/14 01:44, Sanne Grinovero wrote:
> On 12 June 2014 17:46, Dennis Reed <dereed at redhat.com> wrote:
>> +1 to changing the name/directory.
>> -100 to changing the order of where it's looked for instead.
>>
>> All resource lookups should use the normal rules for finding resources.
>> Don't change standard behavior without a *very* good reason.
> There isn't a "standard behaviour", the problem is exactly that it's
> not defined.
> By actually specifying an order we can decide that a user
> configuration file will take priority over our own file, at least
> assuming a modular classloader is being used.
> So indeed it's not a solution for flat classloaders, but it's at least
> correct in that case.
>
> This is what we do in other frameworks: the order in which you look
> for resources needs to be well defined, but it's not in Infinispan.
>
>> Doing anything special (like META-INF/_internal/jgroups-udp.xml) is
>> completely non-intuitive
>> and will cause support issues down the road.
>> Using config/jgroups-udp.xml is standard, and would be immediately
>> understood by anyone.
> I would agree with you about this being a common expectation, but it's
> not rock-solid; we still can't state for sure that the user won't use
> "config" directory too..
>
> The only foolproof solution is to store some signature of the
> jgroups-udp.xml hardcoded in a class, or simply hardcode the whole
> file as a constant.
> We could use the maven inject plugin to maintain the xml file as
> normal source code, and "seal" some constant at build time.. but I
> don't think it's worth it as by defining the lookup order the problem
> is solved in JBoss or WildFly as we would know that the
> infinispan-core.jar classloader is different than the user one, unless
> people bundle the Infinispan jars in their app.
>
> Considering JGroups already logs the full configuration file that it's
> applying, maybe it could log some hash signature as well? This way you
> could just compare the signature to make sure it's using some "well
> known" configuration file.
>
> Sanne
>
>
>> -Dennis
>>
>> On 06/12/2014 07:44 AM, Alan Field wrote:
>>> Tristan,
>>>
>>> So the server and library configuration parsers will handle something like this?
>>>
>>>       <jgroups>
>>>           <stack-file name="jgroupsStack" path="config/jgroups-udp.xml"/>
>>>       </jgroups>
>>>
>>> If this is true, then I agree that this is a good solution as well.
>>>
>>> Thanks,
>>> Alan
>>>
>>> ----- Original Message -----
>>>> From: "Tristan Tarrant" <ttarrant at redhat.com>
>>>> To: "infinispan -Dev List" <infinispan-dev at lists.jboss.org>
>>>> Sent: Thursday, June 12, 2014 2:37:22 PM
>>>> Subject: Re: [infinispan-dev] Issue with JGroups config files in ispn-core
>>>>
>>>> I think the "internal" jgroups files should be "moved" to a separate
>>>> directory within the core jar, to be searched after the "root". So the
>>>> user can still provide a jgroups-udp.xml and it won't conflict.
>>>>
>>>> Tristan
>>>>
>>>> On 12/06/14 14:30, Martin Gencur wrote:
>>>>> Hi,
>>>>> let me mention an issue that several people faced in the past,
>>>>> independently of each other:
>>>>>
>>>>> A user app uses a custom JGroups configuration file. However, they
>>>>> choose the same name as the files which we bundle inside
>>>>> infinispan-core.jar.
>>>>> Result? People are wondering why their custom configuration does not
>>>>> take effect.
>>>>> Reason? Infinispan uses the default jgroups file bundled in infinispan-core
>>>>> Who faced the issue? (I suppose it's just a small subset:)) Me, Radim,
>>>>> Alan, Wolf Fink
>>>>>
>>>>> I believe a lot of users run into this issue.
>>>>>
>>>>> We were considering a possible solution and this one seems like it could
>>>>> work (use both 1) and 2)):
>>>>> 1) rename the config files in the distribution e.g. this way:
>>>>> jgroups-ec2.xml -> default-jgroups-ec2.xml
>>>>> jgroups-udp.xml -> default-jgroups-udp.xml
>>>>> jgroups-tcp.xml -> default-jgroups-tcp.xml
>>>>>
>>>>> Any other suggestions? internal-jgroups-udp.xml ?
>>>>> dontEverUseThisFileInYourAppAsTheCustomConfigurationFile-jgroups-udp.xml
>>>>> ? (joke)
>>>>> (simply something that users would automatically like to change once
>>>>> they use it in their app)
>>>>>
>>>>> 2) Throw a warning whenever a user wants to use a custom jgroups
>>>>> configuration file that has the same name as one of the above
>>>>>
>>>>>
>>>>> WDYT?
>>>>>
>>>>> Thanks!
>>>>> Martin
>>>>>
>>>>> _______________________________________________
>>>>> infinispan-dev mailing list
>>>>> infinispan-dev at lists.jboss.org
>>>>> https://lists.jboss.org/mailman/listinfo/infinispan-dev
>>>>>
>>>>>
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