[Gluster-users] cache before threads or visa versa

Raghavendra G raghavendra at gluster.com
Mon Mar 22 11:37:13 UTC 2010


Hi Ian,

On Mon, Mar 22, 2010 at 2:06 PM, Ian Rogers <ian.rogers at contactclean.com>wrote:

>
> Thanks Raghavendra,
>
> I take it then that a client only makes one TCP conenction to a brick then.
>
> Can the TCP client/server protocol in gluster interleave requests or will
> requests get held up if a brick takes a long time to respond to a previous
> request?
>

Glusterfs client/server (both tcp and ib-verbs) can interleave requests
since the operations are implemented as asynchronous. Two macros STACK_WIND
and STACK_UNWIND (defined in stack.h), are central to this framework.


> Thanks,
>
> Ian
>
>
> On 21/03/2010 06:48, Raghavendra G wrote:
>
>> io-threads gives concurrency in terms of execution, but the data used
>> during execution will be shared by all threads (thread local storage, or the
>> local variables stored on stack etc will not be shared). since io-cache
>> stores the cache in inode structure, the cache stored is the same with or
>> without io-threads.
>>
>> On Sun, Mar 21, 2010 at 5:07 AM, Ian Rogers <ian.rogers at contactclean.com<mailto:
>> ian.rogers at contactclean.com>> wrote:
>>
>>
>>    Can someone familiar with performance/io-threads explain how it
>>    actually works (or write in up in the wiki)?...
>>
>>    I've been doing some experiments with performance/io-threads and
>>    performance/io-cache. I'd expect that if io-threads was the root
>>    of the vol tree then the io-cache would be duplicated along with
>>    the memory usage. But that doesn't seem to be the case...
>>
>>    [snip]
>>
>>
>>    If one puts io-threads in front of protocol/client will the client
>>    be making multiple concurrent TCP connections to the server or not?
>>
>>    Ian
>>    _______________________________________________
>>    Gluster-users mailing list
>>    Gluster-users at gluster.org <mailto:Gluster-users at gluster.org>
>>
>>    http://gluster.org/cgi-bin/mailman/listinfo/gluster-users
>>
>>
>>
>>
>> --
>> Raghavendra G
>>
>>
>
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-- 
Raghavendra G


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