activemq-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Rob Davies <rajdav...@gmail.com>
Subject Re: Paging support
Date Tue, 05 Sep 2006 17:22:19 GMT
A message reference is kept in memory (which consists of a messageId  
and information like sequence Id to enable faster retrieval from  
storage).
There is some work currently in progress in enable paging support in  
ActiveMQ - see http://issues.apache.org/activemq/browse/AMQ-845


On 5 Sep 2006, at 18:07, pradeep wrote:

>
> Maxim,
>
> Can you clarify this
> Are you storing just the message id or the whole message in memory?  
> Your
> help will be highly appreciated.
>
> Thanks
> pradeep
>
>
> Fateev, Maxim wrote:
>>
>> It would be interesting to see some numbers about memory  
>> utilization per
>> message in backlog.
>>
>> IMHO the main problem with keeping references in memory is that it  
>> needs
>> recovery phase on broker startup. It can take a while when backlog is
>> really big.
>>
>> -----Original Message-----
>> From: James Strachan [mailto:james.strachan@gmail.com]
>> Sent: Sunday, September 03, 2006 11:51 PM
>> To: activemq-users@geronimo.apache.org
>> Subject: Re: Paging support
>>
>> Note that MessageReferences != message contents; they are mostly  
>> just a
>> MessageId which is pretty small.
>>
>> On 8/29/06, Fateev, Maxim <fateev@amazon.com> wrote:
>>> AFAIK messages are moved from journal to permantent storage  
>>> (JDBC) on
>>> every checkpoint. The problem is that references for every  
>>> message are
>>> still kept in memory.
>>> IMHO it is inherent limitation of MessageStore API as it is  
>>> defined now.
>>> The only way to get message is by id. And the only way to have id  
>>> is to
>>> keep it in memory.
>>> I'm looking into changing MessageStore API to one that instead of
>>>
>>> Message         getMessage(MessageId identity)
>>>
>>> Would provide
>>>
>>> Message getNextMessage()
>>>
>>> method eliminating need to keep references in memory.
>>>
>>>
>>>
>>> -----Original Message-----
>>> From: Anders Bengtsson [mailto:ndrsbngtssn@yahoo.se]
>>> Sent: Tuesday, August 29, 2006 1:23 AM
>>> To: activemq-users@geronimo.apache.org
>>> Subject: Re: Paging support
>>>
>>>
>>>
>>> gnodet wrote:
>>>>
>>>> If you don' t use any persistent store, messages must be kept in
>>>> memory, so you are obvisouly limited by the available mem.
>>>>
>>>
>>> Yes, this is what I would expect.
>>>
>>>
>>>
>>>> If you use a jdbc store, messages can be removed from memory and
>>>> store for later consumption.
>>>>
>>>
>>> Yes, except it doesn't actually work!
>>>
>>> It writes things to the store, but it is still very much limited by
>>> memory for some reason. (Someone reported this as AMQ-845  
>>> earlier, but
>>> with no response).
>>>
>>> --
>>> View this message in context:
>>> http://www.nabble.com/Paging-support-tf2163517.html#a6034790
>>> Sent from the ActiveMQ - User forum at Nabble.com.
>>>
>>
>>
>> -- 
>>
>> James
>> -------
>> http://radio.weblogs.com/0112098/
>>
>>
>
> -- 
> View this message in context: http://www.nabble.com/Paging-support- 
> tf2163517.html#a6156162
> Sent from the ActiveMQ - User forum at Nabble.com.
>


Mime
View raw message