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Posted to dev@jena.apache.org by Saikat Maitra <sa...@gmail.com> on 2015/01/07 16:43:54 UTC
SPARQL Query Caching
Hi
I am Saikat, I am new to Apache Jena and I would like to contribute to
SPARQL Query Caching (https://issues.apache.org/jira/browse/JENA-626).
I would like to know if someone has already taken up the issue and
currently working on it. I have reviewed the old messages in developers
mail list and I suppose this issue is currently still Unassigned.
Regards
Saikat
Re: SPARQL Query Caching
Posted by Saikat Maitra <sa...@gmail.com>.
Hello Andy,
Thank you for your email. For the caching layer in addition to in-memory
local cache option, I am considering to build provision to use couchbase or
memcache as an option to use remote cache instances from Fuseki server.
Please let me know your feedback.
Regards
Saikat
On Fri, Jan 9, 2015 at 7:08 PM, Andy Seaborne <an...@apache.org> wrote:
> Hi Saikat,
>
> Comments inline
>
> On 08/01/15 12:27, Saikat Maitra wrote:
>
>> Hi Andy
>>
>> Thank you for your email and sharing the external cache implementation. It
>> certainly helped me to understand some of the usecases better.
>>
>> I am thinking to implement the caching layer with a provision to use any
>> of
>> the options below.
>>
>
> Good - I think the key is to get the right abstractions in the code with
> different implementations.
>
> 1. We can use in-memory operation using Guava library and have regular
>> schedule for execution of task to persist the data in disk.
>>
>> 2. The second option is to provide capabilities to use couchbase buckets
>> to
>> store the cache results and have a separate couchbase cluster instance.
>>
>
> Realisically, for most deployments, in-memory is more important.
> Especially as the cost-effective size of servers RAM these days seems to be
> going up so quickly.
>
> I don't know enough about couchbase buckets -- which features do you see
> as most relevant here? As a pratical matter - can they be used separately
> from couchbase?
>
> I am still reading the Fuseki2 server code to understand the server work
>> area.
>>
>
> Andy
>
>
>
>> Regards
>> Saikat
>>
>>
>>
>> On Thu, Jan 8, 2015 at 2:09 AM, Andy Seaborne <an...@apache.org> wrote:
>>
>> On 07/01/15 15:43, Saikat Maitra wrote:
>>>
>>> Hi
>>>>
>>>> I am Saikat, I am new to Apache Jena and I would like to contribute to
>>>> SPARQL Query Caching (https://issues.apache.org/jira/browse/JENA-626).
>>>>
>>>> I would like to know if someone has already taken up the issue and
>>>> currently working on it. I have reviewed the old messages in developers
>>>> mail list and I suppose this issue is currently still Unassigned.
>>>>
>>>> Regards
>>>> Saikat
>>>>
>>>>
>>>> Hi Saikat,
>>>
>>> Good to check - no one seems have mentioned it any time recently.
>>>
>>> There is some code:
>>>
>>> https://svn.apache.org/repos/asf/jena/Experimental/sparql-
>>> cache/README.markdown
>>>
>>> which is an external cache and has some issues:
>>>
>>> 1/ Updates don't invalidate the cache
>>>
>>> 2/ It's a rough prototype in scala I knocked together, not production
>>> tested
>>>
>>> 3/ Claims of "rate control" are overstated (there isn't any).
>>> (seems strange to have it in the cache code at all)
>>>
>>> In Fuseki2, there is a server work area on disk so putting results
>>> somewhere on disk now makes more sense. Or memcached.
>>>
>>> Andy
>>>
>>>
>>>
>>
>
Re: SPARQL Query Caching
Posted by Andy Seaborne <an...@apache.org>.
Hi Saikat,
Comments inline
On 08/01/15 12:27, Saikat Maitra wrote:
> Hi Andy
>
> Thank you for your email and sharing the external cache implementation. It
> certainly helped me to understand some of the usecases better.
>
> I am thinking to implement the caching layer with a provision to use any of
> the options below.
Good - I think the key is to get the right abstractions in the code with
different implementations.
> 1. We can use in-memory operation using Guava library and have regular
> schedule for execution of task to persist the data in disk.
>
> 2. The second option is to provide capabilities to use couchbase buckets to
> store the cache results and have a separate couchbase cluster instance.
Realisically, for most deployments, in-memory is more important.
Especially as the cost-effective size of servers RAM these days seems to
be going up so quickly.
I don't know enough about couchbase buckets -- which features do you see
as most relevant here? As a pratical matter - can they be used
separately from couchbase?
> I am still reading the Fuseki2 server code to understand the server work
> area.
Andy
>
> Regards
> Saikat
>
>
>
> On Thu, Jan 8, 2015 at 2:09 AM, Andy Seaborne <an...@apache.org> wrote:
>
>> On 07/01/15 15:43, Saikat Maitra wrote:
>>
>>> Hi
>>>
>>> I am Saikat, I am new to Apache Jena and I would like to contribute to
>>> SPARQL Query Caching (https://issues.apache.org/jira/browse/JENA-626).
>>>
>>> I would like to know if someone has already taken up the issue and
>>> currently working on it. I have reviewed the old messages in developers
>>> mail list and I suppose this issue is currently still Unassigned.
>>>
>>> Regards
>>> Saikat
>>>
>>>
>> Hi Saikat,
>>
>> Good to check - no one seems have mentioned it any time recently.
>>
>> There is some code:
>>
>> https://svn.apache.org/repos/asf/jena/Experimental/sparql-
>> cache/README.markdown
>>
>> which is an external cache and has some issues:
>>
>> 1/ Updates don't invalidate the cache
>>
>> 2/ It's a rough prototype in scala I knocked together, not production
>> tested
>>
>> 3/ Claims of "rate control" are overstated (there isn't any).
>> (seems strange to have it in the cache code at all)
>>
>> In Fuseki2, there is a server work area on disk so putting results
>> somewhere on disk now makes more sense. Or memcached.
>>
>> Andy
>>
>>
>
Re: SPARQL Query Caching
Posted by Saikat Maitra <sa...@gmail.com>.
Hi Andy
Thank you for your email and sharing the external cache implementation. It
certainly helped me to understand some of the usecases better.
I am thinking to implement the caching layer with a provision to use any of
the options below.
1. We can use in-memory operation using Guava library and have regular
schedule for execution of task to persist the data in disk.
2. The second option is to provide capabilities to use couchbase buckets to
store the cache results and have a separate couchbase cluster instance.
I am still reading the Fuseki2 server code to understand the server work
area.
Regards
Saikat
On Thu, Jan 8, 2015 at 2:09 AM, Andy Seaborne <an...@apache.org> wrote:
> On 07/01/15 15:43, Saikat Maitra wrote:
>
>> Hi
>>
>> I am Saikat, I am new to Apache Jena and I would like to contribute to
>> SPARQL Query Caching (https://issues.apache.org/jira/browse/JENA-626).
>>
>> I would like to know if someone has already taken up the issue and
>> currently working on it. I have reviewed the old messages in developers
>> mail list and I suppose this issue is currently still Unassigned.
>>
>> Regards
>> Saikat
>>
>>
> Hi Saikat,
>
> Good to check - no one seems have mentioned it any time recently.
>
> There is some code:
>
> https://svn.apache.org/repos/asf/jena/Experimental/sparql-
> cache/README.markdown
>
> which is an external cache and has some issues:
>
> 1/ Updates don't invalidate the cache
>
> 2/ It's a rough prototype in scala I knocked together, not production
> tested
>
> 3/ Claims of "rate control" are overstated (there isn't any).
> (seems strange to have it in the cache code at all)
>
> In Fuseki2, there is a server work area on disk so putting results
> somewhere on disk now makes more sense. Or memcached.
>
> Andy
>
>
Re: SPARQL Query Caching
Posted by Andy Seaborne <an...@apache.org>.
On 07/01/15 15:43, Saikat Maitra wrote:
> Hi
>
> I am Saikat, I am new to Apache Jena and I would like to contribute to
> SPARQL Query Caching (https://issues.apache.org/jira/browse/JENA-626).
>
> I would like to know if someone has already taken up the issue and
> currently working on it. I have reviewed the old messages in developers
> mail list and I suppose this issue is currently still Unassigned.
>
> Regards
> Saikat
>
Hi Saikat,
Good to check - no one seems have mentioned it any time recently.
There is some code:
https://svn.apache.org/repos/asf/jena/Experimental/sparql-cache/README.markdown
which is an external cache and has some issues:
1/ Updates don't invalidate the cache
2/ It's a rough prototype in scala I knocked together, not production tested
3/ Claims of "rate control" are overstated (there isn't any).
(seems strange to have it in the cache code at all)
In Fuseki2, there is a server work area on disk so putting results
somewhere on disk now makes more sense. Or memcached.
Andy