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From Kai Wang <>
Subject Re: Acceptable repair time
Date Tue, 29 Mar 2016 12:35:53 GMT
IIRC when we switched to LCS and ran the first full repair with 250GB/RF=3,
it took at least 12 hours for the repair to finish, then another 3+ days
for all the compaction to catch up. I called it "the big bang of LCS".

Since then we've been running nightly incremental repair.

For me as long as it's reliable (no streaming error, better progress
reporting etc), I actually don't mind it it takes more than a few hours to
do a full repair. But I am not sure about 4 days... I guess it depends on
the size of the cluster and data...

On Tue, Mar 29, 2016 at 6:04 AM, Anishek Agarwal <> wrote:

> I would really like to know the answer for above because on some nodes
> repair takes almost 4 days for us :(.
> On Tue, Mar 29, 2016 at 8:34 AM, Jack Krupansky <>
> wrote:
>> Someone recently asked me for advice when their repair time was 2-3 days.
>> I thought that was outrageous, but not unheard of. Personally, to me, 2-3
>> hours would be about the limit of what I could tolerate, and my personal
>> goal would be that a full repair of a node should take no longer than an
>> hour, maybe 90 minutes tops. But... achieving those more abbreviated repair
>> times would strongly suggest that the amount of data on each node be kept
>> down to a tiny fraction of a typical spinning disk drive, or even a
>> fraction of a larger SSD drive.
>> So, my question here is what people consider acceptable full repair times
>> for nodes and what the resulting node data size is.
>> What impact vnodes has on these numbers is a bonus question.
>> Thanks!
>> -- Jack Krupansky

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