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:[EMAIL PROTECTED]
Sent: Sunday, September 03, 2006 11:51 PM
To: [email protected]
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 <[EMAIL PROTECTED]> 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:[EMAIL PROTECTED]
Sent: Tuesday, August 29, 2006 1:23 AM
To: [email protected]
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).
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--
James
-------
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