What is the time between "node down" and "read with R=3" ? Did you "shut down" the node or kill it by brutally powering the box down or yanking the network cable?
It possible that Riak noticed the node_down and had already done the recovery. While net_ticktime can be as long as 60 seconds by default, it's possible that you're hitting the case where you kill it and before you re-run the read it's already noticed and 'fixed itself?' Also, if you do a shutdown, the erlang VM is probably linked/monitoring and being notified that the node is shutting down so it's triggering the rebalance immediately. Try by pulling the network cable out of that node. "/sbin/ifconfig eth0 down" **may** give you the same effect. -mox On Wed, Sep 26, 2012 at 2:51 PM, Tatsuya Kawano <t650...@gmail.com> wrote: > Hi, > > I'm having hard time to verify this behavior on the Riak wiki with my > Riak 1.2 test environment. Can anybody help me to figure out what is > happening? > > > http://wiki.basho.com/Eventual-Consistency.html#Failure-Scenarios > > > Reading When One Primary Fails > > ------------------------------ > > > > 1. Data is written to a key with W=3 > > 2. One node goes down, it happens to be a primary for that key > > 3. Data is read from that key with R=3 > > 4. Riak returns not_found on first request > > 5. Read repair ensures data is replicated to a secondary node. > > Read repair will always occur, regardless of the R value. > > Even with an R of 2, read repair will kick in and ensure that > > all nodes responsible for this particular data are consistent. > > 6. Subsequent reads return correct value with R=3, two values > > coming from primary and one from secondary nodes > > > At the first read (step 4), Riak should return not_found, but it > actually retuns the correct value. I wonder when read repair will kick > in in Riak 1.2. (even before the first read?) > > > I followed the screencast "Tuning CAP Controls in Riak" on this page. > http://wiki.basho.com/Tunable-CAP-Controls-in-Riak.html > > I used riak_core_ring:preflist/2 to ensure that I had took down one of > the correct primary nodes for the key. > > Thanks, > Tatsuya > > -- > Tatsuya Kawano (Mr.) > Tokyo, Japan > > _______________________________________________ > riak-users mailing list > riak-users@lists.basho.com > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com >
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