Great. Thanks for helping us track that down! On Mon, Nov 15, 2010 at 6:45 AM, Eric van Orsouw <eric.van.ors...@eventis.nl> wrote: > Jonathan, I have downloaded 0.6.8 and the iteration problem is fixed. > Thanks, > Eric > > -----Original Message----- > From: Jonathan Ellis [mailto:jbel...@gmail.com] > Sent: donderdag 11 november 2010 23:05 > To: user > Subject: Re: iteration does not yield all data with consistency ONE > > Can you try with the latest 0.6 svn branch? > https://svn.apache.org/repos/asf/cassandra/branches/cassandra-0.6 It > may be caused by https://issues.apache.org/jira/browse/CASSANDRA-1722 > which is fixed there. > > On Thu, Nov 11, 2010 at 4:56 AM, Eric van Orsouw > <eric.van.ors...@eventis.nl> wrote: >> I have tried it with RF=1 and 2 nodes and the result was the same. >> In this case I am not able to query anything, regardless the consistency >> level. >> >> I have conducted some more tests with 4 nodes and RF=2 and before each test >> I also completely cleared all datafiles (data/commit/saved_cache). >> Each time I do this the nodes get different locations on the ring and the >> noticed behavior is different (but similar) each time. >> I have added the details for 2 concrete scenario; >> >> ---- >> 1) clear all 3 data directories for all nodes >> 2) startup all nodes; the ring is; >> >> # bin/nodetool -h 172.16.21.12 ring >> Address Status Load Range >> Ring >> 81296677393575658129031223607666487650 >> 172.16.21.12 Up 489 bytes >> 61644956546475371096781179489550878842 |<--| >> 172.16.21.14 Up 489 bytes >> 63811055530446251457866768401307252614 | | >> 172.16.21.13 Up 489 bytes >> 71622328744148061175473750202165524046 | | >> 172.16.21.11 Up 489 bytes >> 81296677393575658129031223607666487650 |-->| >> >> 3) I use the following ColumnFamily <ColumnFamily Name="Customers" >> ColumnType="Super" CompareWith="AsciiType"/> >> And add the following rows (key and values utf8 strings) >> Customer['1'].simple.id='1' >> Customer['2'].simple.id='2' >> Customer['3'].simple.id='3' >> Customer['4'].simple.id='4' >> >> 4) Iterating over the columns now yield; >> Iterating Nodes .11 thru.13 ==> all rows, regardless of consistency >> level >> Iterating Node.14 ==> only row '3' and '4' with consistency >> level ONE, all rows with consistency level All >> >> ---- >> Repating all process steps again yields the following ring and iteration >> results >> # bin/nodetool -h 172.16.21.11 ring >> Address Status Load Range >> Ring >> 157208721428268855331814529932509412075 >> 172.16.21.11 Up 489 bytes >> 18662665007498667259581716616851966032 |<--| >> 172.16.21.13 Up 489 bytes >> 125997322478065775200568923383951796531 | | >> 172.16.21.12 Up 489 bytes >> 148125235552363592916130178190645177045 | | >> 172.16.21.14 Up 489 bytes >> 157208721428268855331814529932509412075 |-->| >> >> Iterating Nodes .11 .12 .14 ==> no data with consistency level One, >> all rows with consistency level All >> Iterating Node .13 ==> only row '3' and '4' with consistency >> level ONE, all rows with consistency level All >> >> I appears to me there is an inconsistency somewhere, I hope this info helps. >> >> Eric >> >> >> -----Original Message----- >> From: Jonathan Ellis [mailto:jbel...@gmail.com] >> Sent: woensdag 10 november 2010 17:48 >> To: user >> Subject: Re: iteration does not yield all data with consistency ONE >> >> Interesting. Does it simplify further to RF=1 and 2 nodes? >> >> On Wed, Nov 10, 2010 at 8:58 AM, Eric van Orsouw >> <eric.van.ors...@eventis.nl> wrote: >>> No, all nodes were up and running while the single key was inserted. >>> The insert however was with consistency One. I assume however that the >>> replicas are still written in this case. >>> It is btw also very reproducible. >>> >>> -----Original Message----- >>> From: Jonathan Ellis [mailto:jbel...@gmail.com] >>> Sent: woensdag 10 november 2010 15:44 >>> To: user >>> Subject: Re: iteration does not yield all data with consistency ONE >>> >>> Was the node that should have the other replica of this row down when >>> it was inserted? >>> >>> On Wed, Nov 10, 2010 at 6:08 AM, Eric van Orsouw >>> <eric.van.ors...@eventis.nl> wrote: >>>> >>>> Hello, >>>> >>>> >>>> >>>> We have a cluster of 4 nodes (0.6.6) and use the random partitioner and a >>>> replication of 2. >>>> >>>> When I insert a number of rows I can always retrieve them by their >>>> explicit id (get_range_slices("<key>","", 1). >>>> >>>> Playing with consistency levels and temporarily shutting down a Cassandra >>>> node all yields the expected result. >>>> >>>> >>>> >>>> However when I use get_range_slices("","", n) to iterate over all rows, I >>>> sometimes don't get anything (depending on the node). >>>> >>>> >>>> >>>> I then reduced the problem to inserting just a single row. >>>> >>>> Specifically, the 'iteration' only seems to succeed when I issue the >>>> request to the node that contains the first copy. >>>> >>>> I Discovered that when I iterate using a consistency level of Quorum/All >>>> the iteration always succeeds and I properly get the one row. >>>> >>>> >>>> >>>> So a solution would be to always use consistency level One/All but that >>>> has a performance penalty. >>>> >>>> >>>> >>>> Can anyone explain why iterating using get_range_slices("","",n) does not >>>> always function with consistency level One on all nodes? >>>> >>>> >>>> >>>> Thanks, >>>> >>>> Eric >>>> >>>> >>>> >>>> P.S. To rule out any discussion on whether or not to use iteration in the >>>> first place, we only plan to use it for backup and periodic cleanup cycles. >>> >>> >>> -- >>> Jonathan Ellis >>> Project Chair, Apache Cassandra >>> co-founder of Riptano, the source for professional Cassandra support >>> http://riptano.com >>> >> >> >> >> -- >> Jonathan Ellis >> Project Chair, Apache Cassandra >> co-founder of Riptano, the source for professional Cassandra support >> http://riptano.com >> > > > > -- > Jonathan Ellis > Project Chair, Apache Cassandra > co-founder of Riptano, the source for professional Cassandra support > http://riptano.com >
-- Jonathan Ellis Project Chair, Apache Cassandra co-founder of Riptano, the source for professional Cassandra support http://riptano.com
