Thanks, *Tamar Fraenkel * Senior Software Engineer, TOK Media
[image: Inline image 1] ta...@tok-media.com Tel: +972 2 6409736 Mob: +972 54 8356490 Fax: +972 2 5612956 On Mon, Mar 19, 2012 at 11:49 AM, aaron morton <aa...@thelastpickle.com>wrote: > Some information on node failures, consistency levels and availability > http://thelastpickle.com/2011/06/13/Down-For-Me/ > > Cheers > > > ----------------- > Aaron Morton > Freelance Developer > @aaronmorton > http://www.thelastpickle.com > > On 19/03/2012, at 1:08 PM, Watanabe Maki wrote: > > Yes, read and write won't fail with single node failure. > But your read may return old data. > > maki > > On 2012/03/19, at 1:08, Caleb Rackliffe <ca...@steelhouse.com> wrote: > > That sounds right to me :) > > * > Caleb Rackliffe | Software Developer > M 949.981.0159 | ca...@steelhouse.com > ** > <EB2FF764-478C-4966-9B0A-E7B76D6AD7DC[18].png> > * > > From: Tamar Fraenkel <ta...@tok-media.com> > Reply-To: "user@cassandra.apache.org" <user@cassandra.apache.org> > Date: Sun, 18 Mar 2012 04:20:58 -0400 > To: "user@cassandra.apache.org" <user@cassandra.apache.org> > Subject: Re: consistency level question > > Thanks! > I updated replication factor to 2, and now when I took one node down all > continued running (I did see Hector complaining on the node being down), > but things were saved to db and read from it. > > Just so I understand, now, having replication factor of 2, if I have 2 out > of 3 nodes running all my read and writes with CL=1 should work, right? > > > *Tamar Fraenkel * > Senior Software Engineer, TOK Media > > <tokLogo.png> > > ta...@tok-media.com > Tel: +972 2 6409736 > Mob: +972 54 8356490 > Fax: +972 2 5612956 > > > > > > On Sun, Mar 18, 2012 at 9:57 AM, Watanabe Maki <watanabe.m...@gmail.com>wrote: > >> Because your RF is 1, so you need all nodes up. >> >> maki >> >> >> On 2012/03/18, at 16:15, Tamar Fraenkel <ta...@tok-media.com> wrote: >> >> Hi! >> I have a 3 node cassandra cluster. >> I use Hector API. >> >> I give hecotr one of the node's IP address >> I call setAutoDiscoverHosts(true) and setRunAutoDiscoveryAtStartup(true). >> >> The describe on one node returns: >> >> Replication Strategy: org.apache.cassandra.locator.SimpleStrategy >> Durable Writes: true >> Options: [replication_factor:1] >> >> The odd thing is that when I take one of the nodes down, expecting all to >> continue running smoothly, I get exceptions of the format seen bellow, and >> no read or write succeeds. When I bring the node back up, exceptions stop >> and read and write resumes. >> >> Any idea or explanation why this is the case? >> Thanks! >> >> >> me.prettyprint.hector.api.exceptions.HUnavailableException: : May not be >> enough replicas present to handle consistency level. >> at >> me.prettyprint.cassandra.service.ExceptionsTranslatorImpl.translate(ExceptionsTranslatorImpl.java:66) >> at >> me.prettyprint.cassandra.service.KeyspaceServiceImpl$7.execute(KeyspaceServiceImpl.java:285) >> at >> me.prettyprint.cassandra.service.KeyspaceServiceImpl$7.execute(KeyspaceServiceImpl.java:268) >> at >> me.prettyprint.cassandra.service.Operation.executeAndSetResult(Operation.java:103) >> at >> me.prettyprint.cassandra.connection.HConnectionManager.operateWithFailover(HConnectionManager.java:246) >> at >> me.prettyprint.cassandra.service.KeyspaceServiceImpl.operateWithFailover(KeyspaceServiceImpl.java:131) >> at >> me.prettyprint.cassandra.service.KeyspaceServiceImpl.getSlice(KeyspaceServiceImpl.java:289) >> at >> me.prettyprint.cassandra.model.thrift.ThriftSliceQuery$1.doInKeyspace(ThriftSliceQuery.java:53) >> at >> me.prettyprint.cassandra.model.thrift.ThriftSliceQuery$1.doInKeyspace(ThriftSliceQuery.java:49) >> at >> me.prettyprint.cassandra.model.KeyspaceOperationCallback.doInKeyspaceAndMeasure(KeyspaceOperationCallback.java:20) >> at >> me.prettyprint.cassandra.model.ExecutingKeyspace.doExecute(ExecutingKeyspace.java:85) >> at >> me.prettyprint.cassandra.model.thrift.ThriftSliceQuery.execute(ThriftSliceQuery.java:48) >> at >> me.prettyprint.cassandra.service.ColumnSliceIterator.hasNext(ColumnSliceIterator.java:60) >> at >> >> >> *Tamar Fraenkel * >> Senior Software Engineer, TOK Media >> >> <tokLogo.png> >> >> >> ta...@tok-media.com >> Tel: +972 2 6409736 >> Mob: +972 54 8356490 >> Fax: +972 2 5612956 >> >> >> >> > >
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