Hello Tim,
Try to summarize:
- If we use a MemoryPersistenceAdapter that is to say that the Broker
persistent property is set to false, only the memoryUsage and tempUsage limit
could be set.
The storeUsage limit is useless in this case, right ?
- If we use a MemoryPersistenceAdapter and if one of the limits, either
the memoryUsage or the tempUsage, is used, the other will use the physical
limit.
That is to say:
* if we only set the memoryUsage limit then the tempUsage
limit will be the physical available disk space.
* if we only set the tempUsage limit then the memoryUsage
limit will be the physical available memory (maybe limited by the Xmx JVM
settings).
- If we use a MemoryPersistenceAdapter and none of the limits are set
(neither memoryUsage nor the tempUsage limits) then the Broker will compute
these limits
using some formula, right ?
- If we use a MemoryPersistenceAdapter, the way to control everything is
to set the memoryUsage and tempUsage limits, right ?
Best Regards.
-----Original Message-----
From: tbai...@gmail.com [mailto:tbai...@gmail.com] On Behalf Of Tim Bain
Sent: jeudi 9 novembre 2017 06:17
To: ActiveMQ Users <users@activemq.apache.org>
Subject: Re: [++SPAM++]: RE: : Re: WARNING log message to be removed
On Wed, Nov 8, 2017 at 7:29 AM, COURTAULT Francois <
francois.courta...@gemalto.com> wrote:
> Hello Tim,
>
> Understood for the temp store: it looks like a swap mechanism in case
> there is no more room in memory, right ?
>
Just to clarify: it's a swap mechanism in case there is no more room in *the
memory store*, not in memory overall. This is not for paging generic heap
content out to disk if the JVM runs out of heap, etc., and I believe it's also
not for paging out content if you overfill a persistence store that happens to
be backed by memory (though I've not investigated that specific question). But
yes, you understand the overall concept.
> Let's say that, in our configuration, we only set the memoryUsage
> limit without specifying any storeUsage and tempUsage limit .
> In such case, does it exist a formula to calculate the tempUsage limit
> ( eg tempUsage limit=f(memoryUsage limit) )?
>
In that case, no limit is applied, so you're allowed to write content to disk
right up to the point where the write fails (maybe spectacularly) because there
is no more available space on the volume.
> I ask you the question, because if we only set the memoryUsage limit
> to
> 128 mb (no storeUsage and tempUsage limits are set), the WARNING
> message disappears with the same available space on the disk.
>
Yes, the warning message disappears because you've taken the safety off and
told the broker that you're on your own, so it allows you to shoot yourself in
the foot if you so choose without trying to help you avoid doing so. The net
effect for you is the same (the broker won't prevent you from filling the disk
in either configuration), but in one case it tells you that there's a potential
for doing that, and in the other it doesn't attempt to warn you.
Tim
________________________________
This message and any attachments are intended solely for the addressees and
may contain confidential information. Any unauthorized use or disclosure,
either whole or partial, is prohibited.
E-mails are susceptible to alteration. Our company shall not be liable for the
message if altered, changed or falsified. If you are not the intended recipient
of this message, please delete it and notify the sender.
Although all reasonable efforts have been made to keep this transmission free
from viruses, the sender will not be liable for damages caused by a transmitted
virus.
