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From Jonathan Ellis <>
Subject Re: Scaling problems
Date Sun, 23 May 2010 14:42:04 GMT
No, it's really not designed to be a "leave the nodes down while I do
a ton of inserts."

(a) HH schema creates a column per hinted row, so you'll hit the 2GB
row limit sooner or later
(b) it goes through the hints hourly in case it missed a gossip Up notification

On Sat, May 22, 2010 at 9:07 PM, Ian Soboroff <> wrote:
> I'll try this.  HH backs up because nodes are failing.  I haven't read the
> code, but why should HH suck CPU?  As I understand it, there's nothing to
> hand off until the destination comes back up, and Gossip should tell us
> that, no?  In the interim, it's just a cache of writes waiting to be sent.
> Is there some way to tell the system "Just stop caring, I'm just writing,
> let's worry about leveling out when I get around to wanting to read?"
> Ian
> On Fri, May 21, 2010 at 9:06 PM, Jonathan Ellis <> wrote:
>> On Fri, May 21, 2010 at 9:09 AM, Ian Soboroff <> wrote:
>> > HINTED-HANDOFF-POOL               1       158            
>> this is your smoking gun.  HH tasks suck a ton of CPU and you have 158
>> backed up.
>> i would just blow the HH files away from your data/system directory,
>> restart the node, and run repair (assuming all your other nodes are
>> alive again).

Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support

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