i might be wrong, but it seems the error comes from while(itr.hasNext()) not from the add to the queue so i don't think it is related to the number of elements in the queue ... maybe the field lenght?
On 11/21/11, Jonathan Coveney <[email protected]> wrote: > Internally, TOP is using a priority queue. It tries to be smart about > pulling off excess elements, but if you ask it for enough elements, it can > blow up, because the priority queue is going to have n elements, where n is > the ranking you want. This is consistent with the stack trace, which died > on updateTop which is when elements are added to the priority queue. > > Ruslan, how large are the limits you're setting? ie (int)(count * (double) > ($THIRD_LEVELS_PERCENTAGE + $BOTS_PERCENTAGE) ) > > As far as TOP's implementation, I imagine you could get around the issue by > using a sorted data bag, but that might be much slower. hmm. > > 2011/11/21 Ruslan Al-fakikh <[email protected]> > >> Ok. Here it is: >> https://gist.github.com/1383266 >> >> -----Original Message----- >> From: Dmitriy Ryaboy [mailto:[email protected]] >> Sent: 21 ноября 2011 г. 20:32 >> To: [email protected] >> Subject: Re: java.lang.OutOfMemoryError when using TOP udf >> >> Ruslan, I think the mailing list is set to reject attachments -- can you >> post it as a github gist or something similar, and send a link? >> >> D >> >> On Mon, Nov 21, 2011 at 6:11 AM, Ruslan Al-Fakikh >> <[email protected]> wrote: >> > Hey Dmitriy, >> > >> > I attached the script. It is not a plain-pig script, because I make >> > some preprocessing before submitting it to cluster, but the general >> > idea of what I submit is clear. >> > >> > Thanks in advance! >> > >> > On Fri, Nov 18, 2011 at 12:07 AM, Dmitriy Ryaboy <[email protected]> >> wrote: >> >> Ok, so it's something in the rest of the script that's causing this >> >> to happen. Ruslan, if you send your script, I can probably figure out >> >> why (usually, it's using another, non-agebraic udf in your foreach, >> >> or for pig 0.8, generating a constant in the foreach). >> >> >> >> D >> >> >> >> On Thu, Nov 17, 2011 at 9:59 AM, pablomar >> >> <[email protected]> wrote: >> >>> according to the stack trace, the algebraic is not being used it >> >>> says >> >>> updateTop(Top.java:139) >> >>> exec(Top.java:116) >> >>> >> >>> On 11/17/11, Dmitriy Ryaboy <[email protected]> wrote: >> >>>> The top udf does not try to process all data in memory if the >> >>>> algebraic optimization can be applied. It does need to keep the >> >>>> topn numbers in memory of course. Can you confirm algebraic mode is >> used? >> >>>> >> >>>> On Nov 17, 2011, at 6:13 AM, "Ruslan Al-fakikh" >> >>>> <[email protected]> >> >>>> wrote: >> >>>> >> >>>>> Hey guys, >> >>>>> >> >>>>> >> >>>>> >> >>>>> I encounter java.lang.OutOfMemoryError when using TOP udf. It >> >>>>> seems that the udf tries to process all data in memory. >> >>>>> >> >>>>> Is there a workaround for TOP? Or maybe there is some other way of >> >>>>> getting top results? I cannot use LIMIT since I need to 5% of >> >>>>> data, not a constant number of rows. >> >>>>> >> >>>>> >> >>>>> >> >>>>> I am using: >> >>>>> >> >>>>> Apache Pig version 0.8.1-cdh3u2 (rexported) >> >>>>> >> >>>>> >> >>>>> >> >>>>> The stack trace is: >> >>>>> >> >>>>> [2011-11-16 12:34:55] INFO (CodecPool.java:128) - Got brand-new >> >>>>> decompressor >> >>>>> >> >>>>> [2011-11-16 12:34:55] INFO (Merger.java:473) - Down to the last >> >>>>> merge-pass, with 21 segments left of total size: 2057257173 bytes >> >>>>> >> >>>>> [2011-11-16 12:34:55] INFO (SpillableMemoryManager.java:154) - >> >>>>> first memory handler call- Usage threshold init = >> >>>>> 175308800(171200K) used = >> >>>>> 373454552(364701K) committed = 524288000(512000K) max = >> >>>>> 524288000(512000K) >> >>>>> >> >>>>> [2011-11-16 12:36:22] INFO (SpillableMemoryManager.java:167) - >> >>>>> first memory handler call - Collection threshold init = >> >>>>> 175308800(171200K) used = >> >>>>> 496500704(484863K) committed = 524288000(512000K) max = >> >>>>> 524288000(512000K) >> >>>>> >> >>>>> [2011-11-16 12:37:28] INFO (TaskLogsTruncater.java:69) - >> >>>>> Initializing logs' >> >>>>> truncater with mapRetainSize=-1 and reduceRetainSize=-1 >> >>>>> >> >>>>> [2011-11-16 12:37:28] FATAL (Child.java:318) - Error running child : >> >>>>> java.lang.OutOfMemoryError: Java heap space >> >>>>> >> >>>>> at java.util.Arrays.copyOfRange(Arrays.java:3209) >> >>>>> >> >>>>> at java.lang.String.<init>(String.java:215) >> >>>>> >> >>>>> at >> >>>>> java.io.DataInputStream.readUTF(DataInputStream.java:644) >> >>>>> >> >>>>> at >> >>>>> java.io.DataInputStream.readUTF(DataInputStream.java:547) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.data.BinInterSedes.readCharArray(BinInterSedes.java >> >>>>> :210) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.data.BinInterSedes.readDatum(BinInterSedes.java:333 >> >>>>> ) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.data.BinInterSedes.readDatum(BinInterSedes.java:251 >> >>>>> ) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.data.BinInterSedes.addColsToTuple(BinInterSedes.jav >> >>>>> a:555) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.data.BinSedesTuple.readFields(BinSedesTuple.java:64 >> >>>>> ) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.data.InternalCachedBag$CachedBagIterator.hasNext(In >> >>>>> ternalCach >> >>>>> edBag.java:237) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.builtin.TOP.updateTop(TOP.java:139) >> >>>>> >> >>>>> at org.apache.pig.builtin.TOP.exec(TOP.java:116) >> >>>>> >> >>>>> at org.apache.pig.builtin.TOP.exec(TOP.java:65) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.backend.hadoop.executionengine.physicalLayer.expres >> >>>>> sionOperat >> >>>>> ors.POUserFunc.getNext(POUserFunc.java:245) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.backend.hadoop.executionengine.physicalLayer.expres >> >>>>> sionOperat >> >>>>> ors.POUserFunc.getNext(POUserFunc.java:287) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.backend.hadoop.executionengine.physicalLayer.relati >> >>>>> onalOperat >> >>>>> ors.POForEach.processPlan(POForEach.java:338) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.backend.hadoop.executionengine.physicalLayer.relati >> >>>>> onalOperat >> >>>>> ors.POForEach.getNext(POForEach.java:290) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.backend.hadoop.executionengine.physicalLayer.Physic >> >>>>> alOperator >> >>>>> .processInput(PhysicalOperator.java:276) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.backend.hadoop.executionengine.physicalLayer.relati >> >>>>> onalOperat >> >>>>> ors.POForEach.getNext(POForEach.java:240) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMa >> >>>>> pReduce$Re >> >>>>> duce.runPipeline(PigMapReduce.java:434) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMa >> >>>>> pReduce$Re >> >>>>> duce.processOnePackageOutput(PigMapReduce.java:402) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMa >> >>>>> pReduce$Re >> >>>>> duce.reduce(PigMapReduce.java:382) >> >>>>> >> >>>>> at >> >>>>> org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMa >> >>>>> pReduce$Re >> >>>>> duce.reduce(PigMapReduce.java:251) >> >>>>> >> >>>>> at >> >>>>> org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:176) >> >>>>> >> >>>>> at >> >>>>> org.apache.hadoop.mapred.ReduceTask.runNewReducer(ReduceTask.java: >> >>>>> 572) >> >>>>> >> >>>>> at >> >>>>> org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:414) >> >>>>> >> >>>>> at >> >>>>> org.apache.hadoop.mapred.Child$4.run(Child.java:270) >> >>>>> >> >>>>> at >> >>>>> java.security.AccessController.doPrivileged(Native >> >>>>> Method) >> >>>>> >> >>>>> at >> >>>>> javax.security.auth.Subject.doAs(Subject.java:396) >> >>>>> >> >>>>> at >> >>>>> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInfo >> >>>>> rmation.ja >> >>>>> va:1127) >> >>>>> >> >>>>> at >> >>>>> org.apache.hadoop.mapred.Child.main(Child.java:264) >> >>>>> >> >>>>> >> >>>>> >> >>>>> >> >>>>> >> >>>>> >> >>>>> >> >>>>> stderr logs >> >>>>> >> >>>>> Exception in thread "Low Memory Detector" >> >>>>> java.lang.OutOfMemoryError: Java heap space >> >>>>> >> >>>>> at >> >>>>> sun.management.MemoryNotifInfoCompositeData.getCompositeData(Memor >> >>>>> yNotifInfo >> >>>>> CompositeData.java:42) >> >>>>> >> >>>>> at >> >>>>> sun.management.MemoryNotifInfoCompositeData.toCompositeData(Memory >> >>>>> NotifInfoC >> >>>>> ompositeData.java:36) >> >>>>> >> >>>>> at >> >>>>> sun.management.MemoryImpl.createNotification(MemoryImpl.java:168) >> >>>>> >> >>>>> at >> >>>>> >> >> sun.management.MemoryPoolImpl$CollectionSensor.triggerAction(MemoryPoolImpl. >> >>>>> java:300) >> >>>>> >> >>>>> at sun.management.Sensor.trigger(Sensor.java:120) >> >>>>> >> >>>>> >> >>>>> >> >>>>> >> >>>>> >> >>>>> Thanks in advance! >> >>>>> >> >>>> >> >>> >> >> >> > >> > >> > >> > -- >> > Best Regards, >> > Ruslan Al-Fakikh >> > >> >> >
