--------------------------------------------------
| Range changes |
| Bootstrap |
| Adding new nodes is called "bootstrapping." |
-------------------------------------------------
Do you mean that "bootstrapping" is designed for adding new nodes only?
I think the bootstrapping idea is good enough to do something else, for example
that restoring the data in a bad node, though it needs some modification if
that.
What's the difference between a new one which is NOT in the ring before and a
new one which is in the ring before?
I think there are some similarities and differences. (let new one called N, and
the replaced one called R)
* similarities:
Both N and R have no available data, as a result that both of which need to
copy data from the replication soureces.
* differences:
1) About writing while startup
N is not seen before and of couse it has no handoff data in other nodes. As
a result that it should serve for writing which is routed from other nodes
while coping data.
R is seen before and it has handoff data in other nodes, so it will not
care about losing data while coping data from other sources and it will receive
the handoff data after startup. That means R has no need to serve for writing
at that time.
2) About the selection of replication sources
A-->B
| |
D<--C
N want's to insert between B and C, so N knows that it can get data from C, D,
A. After bootstrapping, the ring will be:
A-->B
| |
| N
| |
D<--C
Then the node N is down and replaced with R. Because the R has seen a different
ring, it will select B and C.
From the comparison, I think it's possible that replacing a bad node and
restore the data through bootstrapping.
------------------
XL.Pan
2010-01-15
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发件人：Jonathan Ellis
发送日期：2010-01-15 00:51:57
收件人：cassandra-user
抄送：
主题：Re: replace a bad node through bootstrapping
On Thu, Jan 14, 2010 at 6:30 AM, XL.Pan <pan_xiao...@sina.com> wrote:
> *Why not the standard boostrap?
http://wiki.apache.org/cassandra/Operations says that boostrap is the
preferred method for handling node replacement. Please read how that
describes how to handle things because your description of how
bootstrap works is very off base.
-Joanthan
