cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Tamar Fraenkel <ta...@tok-media.com>
Subject consistency level question
Date Sun, 18 Mar 2012 07:15:53 GMT
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

[image: Inline image 1]

tamar@tok-media.com
Tel:   +972 2 6409736
Mob:  +972 54 8356490
Fax:   +972 2 5612956

Mime
View raw message