cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Apache Wiki <wikidi...@apache.org>
Subject [Cassandra Wiki] Trivial Update of "HadoopSupport" by jeremyhanna
Date Mon, 19 May 2014 12:31:16 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Cassandra Wiki" for change notification.

The "HadoopSupport" page has been changed by jeremyhanna:
https://wiki.apache.org/cassandra/HadoopSupport?action=diff&rev1=58&rev2=59

  If you are running into timeout exceptions, you might need to tweak one or both of these
settings:
  
   * Each input split is divided into sequential batches of rows requested at a time from
Cassandra.  This is the '''cassandra.range.batch.size''' property and it defaults to 4096.
 If you are experiencing timeouts, you might first try to reduce the batch size so that it
can more easily complete the request within the timeout.  This is either specified in your
hadoop configuration or using `org.apache.cassandra.hadoop.ConfigHelper.setRangeBatchSize`.
-  * Starting in Cassandra 1.2, there is range request specific timeout called '''range_request_timeout_in_ms'''
in the cassandra.yaml.  Hadoop will request data in sequential batches and the request has
to complete within this timeout.  Prior to Cassandra 1.2, you're can set the general '''rpc_timeout_in_ms'''
higher, which affects timeouts for reads, writes, and truncate operations in addition to range
requests.
+  * Starting in Cassandra 1.2, there is range request specific timeout called '''range_request_timeout_in_ms'''
in the cassandra.yaml.  Hadoop requests data in sequential batches and each request has to
complete within this timeout.  Prior to Cassandra 1.2, you're can set the general '''rpc_timeout_in_ms'''
higher, which affects timeouts for reads, writes, and truncate operations in addition to range
requests.
  
  If you still see timeout exceptions with resultant failed jobs and/or blacklisted tasktrackers,
there are settings that can give Cassandra more latitude before failing the jobs.  An example
of usage (in either the job configuration or tasktracker mapred-site.xml):
  

Mime
View raw message