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From: Aaron Cordova <aaron@cordovas.org>
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Subject: Re: Suspension
Date: Wed, 15 Feb 2012 10:38:41 -0500
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Such an option would have to be very conspicuous so that users don't =
accidentally enable it and then wonder why bad tablet servers aren't =
removed automatically from the cluster.

It would also require some thought to make sure that large gaps in all =
processes' consciousnesses (5 s's in that word!) don't cause other =
undesirable effects.


On Feb 15, 2012, at 10:31 AM, John Vines wrote:

> That sounds to hacky. Why not just have a Config option for whether zk =
timeouts are heeded?
>=20
> On Feb 15, 2012 10:26 AM, "Adam Fuchs" <adam.p.fuchs@ugov.gov> wrote:
> I think this makes a lot of sense. I use Accumulo enough on a laptop =
to be annoyed at how often I have to run start-all.sh.
>=20
> One way we could do this is to have a separate daemon process restart =
accumulo processes anytime they go down. I think log recovery is almost =
as efficient as any other way of suspending memory to disk, and it =
doesn't add any extra complexity to the code base. The only other =
concern is having the daemon restart a process that should actually be =
down, and we would have to work out the model for that.
>=20
> Adam
>=20
>=20
> On Wed, Feb 15, 2012 at 9:54 AM, Aaron Cordova <aaron@cordovas.org> =
wrote:
> EC2 as well as laptop users would be interested in making Accumulo =
'suspendable'. The self-monitoring features end up killing off processes =
upon awakening. Perhaps this could be implemented by a simple switch =
that tells Accumulo not to worry about abandoning processes that don't =
report, that can be enabled before suspension and disabled after .. or =
simply left enabled for stand-alone laptop users.
>=20
> Does it make sense to make it possible to suspend a running Accumulo =
instance, or should this simply be discouraged and made well known?
>=20
>=20


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<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Such an option would have to be very conspicuous so that users don't accidentally enable it and then wonder why bad tablet servers aren't removed automatically from the cluster.<div><br></div><div>It would also require some thought to make sure that large gaps in all processes' consciousnesses (5 s's in that word!) don't cause other undesirable effects.<br><div><br></div><div><br><div><div>On Feb 15, 2012, at 10:31 AM, John Vines wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><p>That sounds to hacky. Why not just have a Config option for whether zk timeouts are heeded?</p>
<div class="gmail_quote">On Feb 15, 2012 10:26 AM, "Adam Fuchs" &lt;<a href="mailto:adam.p.fuchs@ugov.gov">adam.p.fuchs@ugov.gov</a>&gt; wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
I think this makes a lot of sense. I use Accumulo enough on a laptop to be annoyed at how often I have to run start-all.sh.<div><br></div><div>One way we could do this is to have a separate daemon process restart accumulo processes anytime they go down. I think log recovery is almost as efficient as any other way of suspending memory to disk, and it doesn't add any extra complexity to the code base. The only other concern is having the daemon restart a process that should actually be down, and we would have to work out the model for that.<div>

<br></div><div>Adam<br><div><br></div><div><br><div class="gmail_quote">On Wed, Feb 15, 2012 at 9:54 AM, Aaron Cordova <span dir="ltr">&lt;<a href="mailto:aaron@cordovas.org" target="_blank">aaron@cordovas.org</a>&gt;</span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
EC2 as well as laptop users would be interested in making Accumulo 'suspendable'. The self-monitoring features end up killing off processes upon awakening. Perhaps this could be implemented by a simple switch that tells Accumulo not to worry about abandoning processes that don't report, that can be enabled before suspension and disabled after .. or simply left enabled for stand-alone laptop users.<br>


<br>
Does it make sense to make it possible to suspend a running Accumulo instance, or should this simply be discouraged and made well known?<br>
<br>
</blockquote></div><br></div></div></div>
</blockquote></div>
</blockquote></div><br></div></div></body></html>
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