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From Terje Marthinussen <tmarthinus...@gmail.com>
Subject value of hinted handoff column not really empty...?
Date Wed, 13 Apr 2011 13:59:24 GMT
Hi,

we do see occasional row corruptions now and then and especially in hinted
handoffs.

This may be related to fairly long rows (millions of columns)

I was dumping one corrupted hint .db file and I noticed that they do in fact
have values.

The doc say
Subcolumn values are always empty; instead, we store the row data "normally"

The code does
            add(path, ByteBufferUtil.EMPTY_BYTE_BUFFER,
System.currentTimeMillis(), cf.metadata().getGcGraceSeconds());

and if you run sstable2json you will see that columns have values like
 "4d8eb49d",

I guess an EMPTY_BYTE_BUFFER is not entirely an empty value. Not such a big
deal, but it may be that we are wasting 4 bytes per hint here?

Just a curiosity I thought I would mention before I forget it.

Terje

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