I’ve made few experiments in different settings based on the same code that you used. 1)Created two datasets in hdfs on a cluster of 5 worker nodes and copied them to local fs: val size = 100000000 val partitions = 10 val repetitions = 5 val data = sc.parallelize(1 to size, partitions).map(x => (util.Random.nextInt(size / repetitions), util.Random.nextDouble)).toDF("key", "value") data.write.parquet("hdfs://alex") data.write.parquet(“/home/alex”) val sample = data.sample(true, 0.1) sample.write.parquet("hdfs://alex-10m") sample.write.parquet(“/home/alex-10m”) 2) Run the following code in local mode (spark-shell --master local) and cluster mode (5 nodes with 1 worker each) val df = sqlContext.read.parquet("data") val t = System.nanoTime() df.groupBy("key").sum("value").queryExecution.toRdd.count() println((System.nanoTime() - t) / 1e9) 3) Run the same code in local and cluster mode with persisting the data in memory val df = sqlContext.read.parquet("data") df.persist df.foreach { x => {} } val t = System.nanoTime() df.groupBy("key").sum("value").queryExecution.toRdd.count() println((System.nanoTime() - t) / 1e9)
In the above both cases Tungsten was switched on or off by: sqlContext.setConf("spark.sql.tungsten.enabled", "true" or ”false”). Each experiment was run in a new shell. Below are the results: Data size Mode Storage Tungsten disabled Tungsten enabled 10M Cluster Parquet 9.6 7.4 Persist 10.9 5.1 Local Parquet 57.7 35.8 Persist 61.9 31.4 100M Cluster Parquet 25.4 18.8 Persist 48.6 14.8 Hardware: 6x nodes with 2x Xeon X5650 @ 2.67 32GB RAM, 1 master, 5 workers. Local mode: one node. It seems that there is a nice improvement with Tungsten enabled given that data is persisted in memory 2x and 3x. However, the improvement is not that nice for parquet, it is 1.5x. What’s interesting, with Tungsten enabled performance of in-memory data and parquet data aggregation is similar. Could anyone comment on this? It seems counterintuitive to me. Local performance was not as good as Reynold had. I have around 1.5x, he had 5x. However, local mode is not interesting. From: Reynold Xin [mailto:r...@databricks.com] Sent: Thursday, August 20, 2015 9:24 PM To: Ulanov, Alexander Cc: dev@spark.apache.org Subject: Re: Dataframe aggregation with Tungsten unsafe Not sure what's going on or how you measure the time, but the difference here is pretty big when I test on my laptop. Maybe you set the wrong config variables? (spark.sql.* are sql variables that you set in sqlContext.setConf -- and in 1.5, they are consolidated into a single flag: spark.sql.tungsten.enabled. See below. I ran with a 10m dataset (created by calling sample(true, 0.1) on the 100m dataset), since the 100m one takes too long when tungsten is off on my laptop so I didn't wait. (40s - 50s with Tungsten on) val df = sqlContext.read.parquet("/scratch/rxin/tmp/alex-10m") val t = System.nanoTime() df.groupBy("key").sum("value").queryExecution.toRdd.count() println((System.nanoTime() - t) / 1e9) On 1.5, with 8g driver memory and 8 cores: 5.48951 sqlContext.setConf("spark.sql.tungsten.enabled", "false") run it again, and took 25.127962. On 1.4, with 8g driver memory and 8 cores: 25.583473 It's also possible that the benefit is less when you have infinite amount of memory (relative to the tiny dataset size) and as a result GC happens less. On Thu, Aug 20, 2015 at 7:00 PM, Ulanov, Alexander <alexander.ula...@hp.com<mailto:alexander.ula...@hp.com>> wrote: Did git pull :) Now I do get the difference in time between on/off Tungsten unsafe: it is 24-25 seconds (unsafe on) vs 32-26 seconds (unsafe off) for the example below. Why I am not getting the improvement as advertised on Spark Summit (slide 23)? http://www.slideshare.net/SparkSummit/deep-dive-into-project-tungsten-josh-rosen My dataset is 100M rows, is it big enough to get the improvement? Do I use aggregate correctly? case class Counter(key: Int, value: Double) val size = 100000000 val partitions = 5 val repetitions = 5 val data = sc.parallelize(1 to size, partitions).map(x => Counter(util.Random.nextInt(size / repetitions), util.Random.nextDouble)) val df = sqlContext.createDataFrame(data) df.persist() df.foreach { x => {} } val t = System.nanoTime() val res = df.groupBy("key").agg(sum("value")) res.foreach { x => {} } println((System.nanoTime() - t) / 1e9) Unsafe on: spark.sql.codegen true spark.sql.unsafe.enabled true spark.unsafe.offHeap true Unsafe off: spark.sql.codegen false spark.sql.unsafe.enabled false spark.unsafe.offHeap false From: Reynold Xin [mailto:r...@databricks.com<mailto:r...@databricks.com>] Sent: Thursday, August 20, 2015 5:43 PM To: Ulanov, Alexander Cc: dev@spark.apache.org<mailto:dev@spark.apache.org> Subject: Re: Dataframe aggregation with Tungsten unsafe Please git pull :) On Thu, Aug 20, 2015 at 5:35 PM, Ulanov, Alexander <alexander.ula...@hp.com<mailto:alexander.ula...@hp.com>> wrote: I am using Spark 1.5 cloned from master on June 12. (The aggregate unsafe feature was added to Spark on April 29.) From: Reynold Xin [mailto:r...@databricks.com<mailto:r...@databricks.com>] Sent: Thursday, August 20, 2015 5:26 PM To: Ulanov, Alexander Cc: dev@spark.apache.org<mailto:dev@spark.apache.org> Subject: Re: Dataframe aggregation with Tungsten unsafe Yes - DataFrame and SQL are the same thing. Which version are you running? Spark 1.4 doesn't run Janino --- but you have a Janino exception? On Thu, Aug 20, 2015 at 5:01 PM, Ulanov, Alexander <alexander.ula...@hp.com<mailto:alexander.ula...@hp.com>> wrote: When I add the following option: spark.sql.codegen true Spark crashed on the “df.count” with concurrentException (below). Are you sure that I need to set this flag to get unsafe? It looks like SQL flag, and I don’t use sql. java.util.concurrent.ExecutionException: org.codehaus.commons.compiler.CompileException: Line 14, Column 10: Override at org.spark-project.guava.util.concurrent.AbstractFuture$Sync.getValue(AbstractFuture.java:306) at org.spark-project.guava.util.concurrent.AbstractFuture$Sync.get(AbstractFuture.java:293) at org.spark-project.guava.util.concurrent.AbstractFuture.get(AbstractFuture.java:116) at org.spark-project.guava.util.concurrent.Uninterruptibles.getUninterruptibly(Uninterruptibles.java:135) at org.spark-project.guava.cache.LocalCache$Segment.getAndRecordStats(LocalCache.java:2410) at org.spark-project.guava.cache.LocalCache$Segment.loadSync(LocalCache.java:2380) at org.spark-project.guava.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2342) at org.spark-project.guava.cache.LocalCache$Segment.get(LocalCache.java:2257) at org.spark-project.guava.cache.LocalCache.get(LocalCache.java:4000) at org.spark-project.guava.cache.LocalCache.getOrLoad(LocalCache.java:4004) at org.spark-project.guava.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4874) at org.apache.spark.sql.catalyst.expressions.codegen.CodeGenerator.generate(CodeGenerator.scala:286) at org.apache.spark.sql.catalyst.expressions.codegen.CodeGenerator.generate(CodeGenerator.scala:283) at org.apache.spark.sql.execution.SparkPlan.newPredicate(SparkPlan.scala:180) at org.apache.spark.sql.columnar.InMemoryColumnarTableScan$$anonfun$8.apply(InMemoryColumnarTableScan.scala:277) at org.apache.spark.sql.columnar.InMemoryColumnarTableScan$$anonfun$8.apply(InMemoryColumnarTableScan.scala:276) at org.apache.spark.rdd.RDD$$anonfun$mapPartitions$1$$anonfun$apply$17.apply(RDD.scala:686) at org.apache.spark.rdd.RDD$$anonfun$mapPartitions$1$$anonfun$apply$17.apply(RDD.scala:686) at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:35) at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:277) at org.apache.spark.rdd.RDD.iterator(RDD.scala:244) at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:35) at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:277) at org.apache.spark.rdd.RDD.iterator(RDD.scala:244) at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:35) at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:277) at org.apache.spark.rdd.RDD.iterator(RDD.scala:244) at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:70) at org.apache.spark.scheduler.ShuffleMapTask.runTask(ShuffleMapTask.scala:41) at org.apache.spark.scheduler.Task.run(Task.scala:70) at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:213) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745) Caused by: org.codehaus.commons.compiler.CompileException: Line 14, Column 10: Override at org.codehaus.janino.UnitCompiler.findTypeByName(UnitCompiler.java:6897) at org.codehaus.janino.UnitCompiler.getReferenceType(UnitCompiler.java:5331) at org.codehaus.janino.UnitCompiler.getReferenceType(UnitCompiler.java:5207) at org.codehaus.janino.UnitCompiler.getType2(UnitCompiler.java:5188) at org.codehaus.janino.UnitCompiler.access$12600(UnitCompiler.java:185) at org.codehaus.janino.UnitCompiler$16.visitReferenceType(UnitCompiler.java:5119) at org.codehaus.janino.Java$ReferenceType.accept(Java.java:2880) at org.codehaus.janino.UnitCompiler.getType(UnitCompiler.java:5159) at org.codehaus.janino.UnitCompiler.hasAnnotation(UnitCompiler.java:830) at org.codehaus.janino.UnitCompiler.compileDeclaredMethods(UnitCompiler.java:814) at org.codehaus.janino.UnitCompiler.compileDeclaredMethods(UnitCompiler.java:794) at org.codehaus.janino.UnitCompiler.compile2(UnitCompiler.java:507) at org.codehaus.janino.UnitCompiler.compile2(UnitCompiler.java:658) at org.codehaus.janino.UnitCompiler.compile2(UnitCompiler.java:662) at org.codehaus.janino.UnitCompiler.access$600(UnitCompiler.java:185) at org.codehaus.janino.UnitCompiler$2.visitMemberClassDeclaration(UnitCompiler.java:350) at org.codehaus.janino.Java$MemberClassDeclaration.accept(Java.java:1035) at org.codehaus.janino.UnitCompiler.compile(UnitCompiler.java:354) at org.codehaus.janino.UnitCompiler.compileDeclaredMemberTypes(UnitCompiler.java:769) at org.codehaus.janino.UnitCompiler.compile2(UnitCompiler.java:532) at org.codehaus.janino.UnitCompiler.compile2(UnitCompiler.java:393) at org.codehaus.janino.UnitCompiler.access$400(UnitCompiler.java:185) at org.codehaus.janino.UnitCompiler$2.visitPackageMemberClassDeclaration(UnitCompiler.java:347) at org.codehaus.janino.Java$PackageMemberClassDeclaration.accept(Java.java:1139) at org.codehaus.janino.UnitCompiler.compile(UnitCompiler.java:354) at org.codehaus.janino.UnitCompiler.compileUnit(UnitCompiler.java:322) at org.codehaus.janino.SimpleCompiler.compileToClassLoader(SimpleCompiler.java:383) at org.codehaus.janino.ClassBodyEvaluator.compileToClass(ClassBodyEvaluator.java:315) at org.codehaus.janino.ClassBodyEvaluator.cook(ClassBodyEvaluator.java:233) at org.codehaus.janino.SimpleCompiler.cook(SimpleCompiler.java:192) at org.codehaus.commons.compiler.Cookable.cook(Cookable.java:84) at org.codehaus.commons.compiler.Cookable.cook(Cookable.java:77) at org.codehaus.janino.ClassBodyEvaluator.<init>(ClassBodyEvaluator.java:72) at org.apache.spark.sql.catalyst.expressions.codegen.CodeGenerator.compile(CodeGenerator.scala:246) at org.apache.spark.sql.catalyst.expressions.codegen.GeneratePredicate$.create(GeneratePredicate.scala:64) at org.apache.spark.sql.catalyst.expressions.codegen.GeneratePredicate$.create(GeneratePredicate.scala:32) at org.apache.spark.sql.catalyst.expressions.codegen.CodeGenerator$$anon$1.load(CodeGenerator.scala:273) at org.spark-project.guava.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3599) at org.spark-project.guava.cache.LocalCache$Segment.loadSync(LocalCache.java:2379) ... 28 more Caused by: java.lang.ClassNotFoundException: Override at org.apache.spark.repl.ExecutorClassLoader.findClass(ExecutorClassLoader.scala:69) at java.lang.ClassLoader.loadClass(ClassLoader.java:425) at java.lang.ClassLoader.loadClass(ClassLoader.java:358) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:270) at org.codehaus.janino.ClassLoaderIClassLoader.findIClass(ClassLoaderIClassLoader.java:78) at org.codehaus.janino.IClassLoader.loadIClass(IClassLoader.java:254) at org.codehaus.janino.UnitCompiler.findTypeByName(UnitCompiler.java:6893) ... 66 more Caused by: java.lang.ClassNotFoundException: Override at java.lang.ClassLoader.findClass(ClassLoader.java:531) at org.apache.spark.util.ParentClassLoader.findClass(ParentClassLoader.scala:26) at java.lang.ClassLoader.loadClass(ClassLoader.java:425) at org.apache.spark.util.ParentClassLoader.loadClass(ParentClassLoader.scala:34) at java.lang.ClassLoader.loadClass(ClassLoader.java:358) at org.apache.spark.util.ParentClassLoader.loadClass(ParentClassLoader.scala:30) at org.apache.spark.repl.ExecutorClassLoader.findClass(ExecutorClassLoader.scala:64) ... 73 more From: Reynold Xin [mailto:r...@databricks.com<mailto:r...@databricks.com>] Sent: Thursday, August 20, 2015 4:22 PM To: Ulanov, Alexander Cc: dev@spark.apache.org<mailto:dev@spark.apache.org> Subject: Re: Dataframe aggregation with Tungsten unsafe I think you might need to turn codegen on also in order for the unsafe stuff to work. On Thu, Aug 20, 2015 at 4:09 PM, Ulanov, Alexander <alexander.ula...@hp.com<mailto:alexander.ula...@hp.com>> wrote: Hi Reynold, Thank you for suggestion. This code takes around 30 sec on my setup (5 workers with 32GB). My issue is that I don't see the change in time if I unset the unsafe flags. Could you explain why it might happen? 20 авг. 2015 г., в 15:32, Reynold Xin <r...@databricks.com<mailto:r...@databricks.com><mailto:r...@databricks.com<mailto:r...@databricks.com>>> написал(а): I didn't wait long enough earlier. Actually it did finish when I raised memory to 8g. In 1.5 with Tungsten (which should be the same as 1.4 with your unsafe flags), the query took 40s with 4G of mem. In 1.4, it took 195s with 8G of mem. This is not a scientific benchmark and I only ran it once. On Thu, Aug 20, 2015 at 3:22 PM, Reynold Xin <r...@databricks.com<mailto:r...@databricks.com><mailto:r...@databricks.com<mailto:r...@databricks.com>>> wrote: How did you run this? I couldn't run your query with 4G of RAM in 1.4, but in 1.5 it ran. Also I recommend just dumping the data to parquet on disk to evaluate, rather than using the in-memory cache, which is super slow and we are thinking of removing/replacing with something else. val size = 100000000 val partitions = 10 val repetitions = 5 val data = sc.parallelize(1 to size, partitions).map(x => (util.Random.nextInt(size / repetitions), util.Random.nextDouble)).toDF("key", "value") data.write.parquet("/scratch/rxin/tmp/alex") val df = sqlContext.read.parquet("/scratch/rxin/tmp/alex") val t = System.nanoTime() val res = df.groupBy("key").agg(sum("value")) res.count() println((System.nanoTime() - t) / 1e9) On Thu, Aug 20, 2015 at 2:57 PM, Ulanov, Alexander <alexander.ula...@hp.com<mailto:alexander.ula...@hp.com><mailto:alexander.ula...@hp.com<mailto:alexander.ula...@hp.com>>> wrote: Dear Spark developers, I am trying to benchmark the new Dataframe aggregation implemented under the project Tungsten and released with Spark 1.4 (I am using the latest Spark from the repo, i.e. 1.5): https://github.com/apache/spark/pull/5725 It tells that the aggregation should be faster due to using the unsafe to allocate memory and in-place update. It was also presented on Spark Summit this Summer: http://www.slideshare.net/SparkSummit/deep-dive-into-project-tungsten-josh-rosen The following enables the new aggregation in spark-config: spark.sql.unsafe.enabled=true spark.unsafe.offHeap=true I wrote a simple code that does aggregation of values by keys. However, the time needed to execute the code does not depend if the new aggregation is on or off. Could you suggest how can I observe the improvement that the aggregation provides? Could you write a code snippet that takes advantage of the new aggregation? case class Counter(key: Int, value: Double) val size = 100000000 val partitions = 5 val repetitions = 5 val data = sc.parallelize(1 to size, partitions).map(x => Counter(util.Random.nextInt(size / repetitions), util.Random.nextDouble)) val df = sqlContext.createDataFrame(data) df.persist() df.count() val t = System.nanoTime() val res = df.groupBy("key").agg(sum("value")) res.count() println((System.nanoTime() - t) / 1e9) Best regards, Alexander