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Posted to users@activemq.apache.org by xabhi <xa...@gmail.com> on 2014/02/13 08:43:29 UTC
Slow KahaDB access
Hi,
How frequently are these slow kahadb messages are logged?
I checked source code and found that these are logged during cleanup,
journal append and journal read.
I know cleanup happens only after cleanup interval but I know nothing about
how frequently journal append and journal read happens.
Does journal append and read happens for every new persistent message that
is received by the broker? or it happens after some time interval, if yes
can it be configured?
Thanks,
Abhi
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Re: Slow KahaDB access
Posted by xabhi <xa...@gmail.com>.
Can anybody answer the queries posted in previous post.
-
Abhi
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Re: Slow KahaDB access
Posted by Christian Posta <ch...@gmail.com>.
Try it out. And check the source. The source is your friend. We are an
open source community, and happy to be so.
On Tue, Feb 25, 2014 at 2:52 AM, xabhi <xa...@gmail.com> wrote:
> Please respond....
>
> -
> Abhi
>
>
>
> --
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Re: Slow KahaDB access
Posted by xabhi <xa...@gmail.com>.
Please respond....
-
Abhi
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Re: Slow KahaDB access
Posted by xabhi <xa...@gmail.com>.
Hi,
I have few more queries:
1. IIUC, If there is only one producer sending persistent messages, then
journal writes will happen for every message and Slow KahaDB access logging
will be done for every message.
2. In what cases does "Slow KahaDB access: Journal read took " will logged?
In which cases a journal read operation takes place?
3. Does LevelDB also have a similar kind of Slow file system access logging?
If not then why it is dropped?
Thanks,
Abhi
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Re: Slow KahaDB access
Posted by Gary Tully <ga...@gmail.com>.
the journal will batch writes, but does not delay, so under parallel
load (multiple connections), there will be batching. Batch writes can
accumulate while a write to disk and sync is in progress.
On 17 February 2014 07:01, xabhi <xa...@gmail.com> wrote:
> Hi,
> I have read that page and I could only find that the logging will be done
> after cleanup or checkpoint interval.
> But its not clear what happens when a persistent message arrives at broker.
> Does journal write happens as soon as a persistent message arrives(i.e.
> separately for every persistent message) or a bunch of messages are
> persisted together?
>
>
> Thanks,
> Abhi
>
>
>
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Re: Slow KahaDB access
Posted by xabhi <xa...@gmail.com>.
Hi,
I have read that page and I could only find that the logging will be done
after cleanup or checkpoint interval.
But its not clear what happens when a persistent message arrives at broker.
Does journal write happens as soon as a persistent message arrives(i.e.
separately for every persistent message) or a bunch of messages are
persisted together?
Thanks,
Abhi
--
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Re: Slow KahaDB access
Posted by Johan Edstrom <se...@gmail.com>.
http://activemq.apache.org/kahadb.html
On Feb 14, 2014, at 10:19 AM, xabhi <xa...@gmail.com> wrote:
> Can somebody from activemq dev answer these queries please?
>
> Thanks,
> Abhi
>
>
>
> --
> View this message in context: http://activemq.2283324.n4.nabble.com/Slow-KahaDB-access-tp4677915p4677981.html
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Re: Slow KahaDB access
Posted by xabhi <xa...@gmail.com>.
Can somebody from activemq dev answer these queries please?
Thanks,
Abhi
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