我有7个cassandra节点(5 nodes with 32 cores and 32G memory, and 4 nodes with 4 cores and 64G memory
),并在这个集群上部署了火花工作者,火花的主人在8th node
。我为他们使用了spark-cassandra-connector。现在我的卡桑德拉有近十亿记录有30场,我写的斯卡拉包括下面的代码片段:为什么我在使用spark + cassandra时出现错误:“Size exceeded Integer.MAX_VALUE”?
def startOneCache(): DataFrame = {
val conf = new SparkConf(true)
.set("spark.cassandra.connection.host", "192.168.0.184")
.set("spark.cassandra.auth.username", "username")
.set("spark.cassandra.auth.password", "password")
.set("spark.driver.maxResultSize", "4G")
.set("spark.executor.memory", "12G")
.set("spark.cassandra.input.split.size_in_mb","64")
val sc = new SparkContext("spark://192.168.0.131:7077", "statistics", conf)
val cc = new CassandraSQLContext(sc)
val rdd: DataFrame = cc.sql("select user_id,col1,col2,col3,col4,col5,col6
,col7,col8 from user_center.users").limit(100000192)
val rdd_cache: DataFrame = rdd.cache()
rdd_cache.count()
return rdd_cache
}
在火花的主我用运行上面的代码,在执行语句时:rdd_cache.count()
,我在一个工人节点的ERROR
:192.168.0.185
:
16/03/08 15:38:57 INFO ShuffleBlockFetcherIterator: Started 4 remote fetches in 221 ms
16/03/08 15:43:49 WARN MemoryStore: Not enough space to cache rdd_6_0 in memory! (computed 4.6 GB so far)
16/03/08 15:43:49 INFO MemoryStore: Memory use = 61.9 KB (blocks) + 4.6 GB (scratch space shared across 1 tasks(s)) = 4.6 GB. Storage limit = 6.2 GB.
16/03/08 15:43:49 WARN CacheManager: Persisting partition rdd_6_0 to disk instead.
16/03/08 16:13:11 ERROR Executor: Managed memory leak detected; size = 4194304 bytes, TID = 24002
16/03/08 16:13:11 ERROR Executor: Exception in task 0.0 in stage 1.0 (TID 24002)
java.lang.IllegalArgumentException: Size exceeds Integer.MAX_VALUE
我只是想到,最后的错误Size exceeds Integer.MAX_VALUE
被警告引起:16/03/08 15:43:49 WARN MemoryStore: Not enough space to cache rdd_6_0 in memory! (computed 4.6 GB so far)
之前,但我不知道为什么,还是我应该设定一个大于.set("spark.executor.memory", "12G")
,应该怎么做我为了纠正这个吗?
尽管这是一个正确的答案,但一些解释是有用的。 – zero323
'拉多Buransky',谢谢!我应该怎么做才能得到当前rdd中有多少个分区?在我的Spark UI中,总任务是'23660',这是当前的分区数量,如果是的话,我应该设置多少个分区来解决这个错误? – abelard2008
@ abelard2008试试这个:https://databricks.gitbooks.io/databricks-spark-knowledge-base/content/performance_optimization/how_many_partitions_does_an_rdd_have.html –