Since your Hbase is supported by the external vendor, I would ask them to justify their choice of storage for Hbase and any suggestion they have vis-a-vis S3 etc.
Spark has an efficient API to Hbase including remote Hbase. I have used in the past reading from Hbase. HTH view my Linkedin profile <https://www.linkedin.com/in/mich-talebzadeh-ph-d-5205b2/> https://en.everybodywiki.com/Mich_Talebzadeh *Disclaimer:* Use it at your own risk. Any and all responsibility for any loss, damage or destruction of data or any other property which may arise from relying on this email's technical content is explicitly disclaimed. The author will in no case be liable for any monetary damages arising from such loss, damage or destruction. On Thu, 7 Apr 2022 at 13:38, Joris Billen <joris.bil...@bigindustries.be> wrote: > Thanks for pointing this out. > > So currently data is stored in hbase on adls. Question (sorry I might be > ignorant): is it clear that parquet on s3 would be faster as storage to > read from than hbase on adls? > In general, I ve found it hard after my processing is done, if I have an > application that needs to read all data from hbase (full large tables) to > get this as fast as possible. > This read speed is important to me, but it is limited (I think) by the > time it will take to read the data from the cloud storage (adls). > You can change some parameters (like regionserver heap , block.cache size, > memstore global size) depending on if you are processing/write a lot OR > reading from hbase. What I would find really useful if one of these > autoscaling systems could also optimize these parameters depending if youre > reading or writing. > > > > Wrt architecture: indeed separate spark from hbase would be best , but I > never got it to write from an outside spark cluster. For autoscaling, I > know there are hbase cloud offerings that have elastic scaling so indeed > that could be an improvement too. > > > > ANyhow, fruitful discussion. > > > > > > On 7 Apr 2022, at 13:46, Bjørn Jørgensen <bjornjorgen...@gmail.com> wrote: > > "4. S3: I am not using it, but people in the thread started suggesting > potential solutions involving s3. It is an azure system, so hbase is stored > on adls. In fact the nature of my application (geospatial stuff) requires > me to use geomesa libs, which only allows directly writing from spark to > hbase. So I can not write to some other format (the geomesa API is not > designed for that-it only writes directly to hbase using the predetermined > key/values)." > > In the docs for geomesa it looks like it can write to files. They say to > AWS which S3 is a part of and " The quick start comes pre-configured to > use Apache’s Parquet encoding." > > http://www.geomesa.org/documentation/current/tutorials/geomesa-quickstart-fsds.html > <https://eur02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.geomesa.org%2Fdocumentation%2Fcurrent%2Ftutorials%2Fgeomesa-quickstart-fsds.html&data=04%7C01%7Cjoris.billen%40bigindustries.be%7C7101a6f47bb1413e860e08da188c4712%7C49c3d703357947bfa8887c913fbdced9%7C0%7C0%7C637849288493392207%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=8qm7wKBpwbXljd0uFvl6QW7UGKERUQtm%2FASe%2Bt2qr9E%3D&reserved=0> > > > > tor. 7. apr. 2022 kl. 13:30 skrev Mich Talebzadeh < > mich.talebza...@gmail.com>: > >> Ok. Your architect has decided to emulate anything on prem to the >> cloud.You are not really taking any advantages of cloud offerings or >> scalability. For example, how does your Hadoop clustercater for the >> increased capacity. Likewise your spark nodes are pigeonholed with your >> Hadoop nodes. Old wine in a new bottle :) >> >> HTH >> >> view my Linkedin profile >> <https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.linkedin.com%2Fin%2Fmich-talebzadeh-ph-d-5205b2%2F&data=04%7C01%7Cjoris.billen%40bigindustries.be%7C7101a6f47bb1413e860e08da188c4712%7C49c3d703357947bfa8887c913fbdced9%7C0%7C0%7C637849288493392207%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=eiHW2%2FbI5kF91lzXlYhvJWilntztze4kNRcRvJj6IV4%3D&reserved=0> >> >> >> https://en.everybodywiki.com/Mich_Talebzadeh >> <https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fen.everybodywiki.com%2FMich_Talebzadeh&data=04%7C01%7Cjoris.billen%40bigindustries.be%7C7101a6f47bb1413e860e08da188c4712%7C49c3d703357947bfa8887c913fbdced9%7C0%7C0%7C637849288493392207%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=2kdSWdHDFiESyJ8WCc7YmH9XHUy%2BsNhSGGs%2Bq8LlvWI%3D&reserved=0> >> >> >> *Disclaimer:* Use it at your own risk. Any and all responsibility for >> any loss, damage or destruction of data or any other property which may >> arise from relying on this email's technical content is explicitly >> disclaimed. The author will in no case be liable for any monetary damages >> arising from such loss, damage or destruction. >> >> >> >> >> On Thu, 7 Apr 2022 at 09:20, Joris Billen <joris.bil...@bigindustries.be> >> wrote: >> >>> Thanks for active discussion and sharing your knowledge :-) >>> >>> >>> 1.Cluster is a managed hadoop cluster on Azure in the cloud. It has >>> hbase, and spark, and hdfs shared . >>> 2.Hbase is on the cluster, so not standalone. It comes from an >>> enterprise-level template from a commercial vendor, so assuming this is >>> correctly installed. >>> 3.I know that woudl be best to have a spark cluster to do the processing >>> and then write to a separate hbase cluster.. but alas :-( somehow we found >>> this to be buggy so we have it all on one cluster. >>> 4. S3: I am not using it, but people in the thread started suggesting >>> potential solutions involving s3. It is an azure system, so hbase is stored >>> on adls. In fact the nature of my application (geospatial stuff) requires >>> me to use geomesa libs, which only allows directly writing from spark to >>> hbase. So I can not write to some other format (the geomesa API is not >>> designed for that-it only writes directly to hbase using the predetermined >>> key/values). >>> >>> Forgot to mention: I do unpersist my df that was cached. >>> >>> Nevertheless I think I understand the problem now, this discussion is >>> still interesting! >>> So the root cause is : the hbase region server has memory assigned to it >>> (like 20GB). I see when I start writing from spark to hbase, not much of >>> this is used. I have loops of processing 1 day in spark. For each loop, the >>> regionserver heap is filled a bit more. Since I also overcommitted memory >>> in my cluster (have used in the setup more than really is available), tfter >>> several loops it starts to use more and more of the 20GB and eventually the >>> overall cluster starts to hit the memory that is available on the workers. >>> The solution is to lower the hbase regionserver heap memory, so Im not >>> overcommitted anymore. In fact, high regionserver memory is more important >>> when I read my data, since then it helps a lot to cache data and to have >>> faster reads. For writing it is not important to have such a high value. >>> >>> >>> Thanks, >>> Joris >>> >>> >>> On 7 Apr 2022, at 09:26, Mich Talebzadeh <mich.talebza...@gmail.com> >>> wrote: >>> >>> Ok so that is your assumption. The whole thing is based on-premise on >>> JBOD (including hadoop cluster which has Spark binaries on each node as I >>> understand) as I understand. But it will be faster to use S3 (or GCS) >>> through some network and it will be faster than writing to the local SSD. I >>> don't understand the point here. >>> >>> Also it appears the thread owner is talking about having HBase on Hadoop >>> cluster on some node eating memory. This can be easily sorted by moving >>> HBase to its own cluster, which will ease up Hadoop, Spark and HBase >>> competing for resources. It is possible that the issue is with HBase setup >>> as well. >>> >>> HTH >>> >>> >>> view my Linkedin profile >>> <https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.linkedin.com%2Fin%2Fmich-talebzadeh-ph-d-5205b2%2F&data=04%7C01%7Cjoris.billen%40bigindustries.be%7C7101a6f47bb1413e860e08da188c4712%7C49c3d703357947bfa8887c913fbdced9%7C0%7C0%7C637849288493392207%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=eiHW2%2FbI5kF91lzXlYhvJWilntztze4kNRcRvJj6IV4%3D&reserved=0> >>> >>> >>> https://en.everybodywiki.com/Mich_Talebzadeh >>> <https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fen.everybodywiki.com%2FMich_Talebzadeh&data=04%7C01%7Cjoris.billen%40bigindustries.be%7C7101a6f47bb1413e860e08da188c4712%7C49c3d703357947bfa8887c913fbdced9%7C0%7C0%7C637849288493392207%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=2kdSWdHDFiESyJ8WCc7YmH9XHUy%2BsNhSGGs%2Bq8LlvWI%3D&reserved=0> >>> >>> >>> *Disclaimer:* Use it at your own risk. Any and all responsibility for >>> any loss, damage or destruction of data or any other property which may >>> arise from relying on this email's technical content is explicitly >>> disclaimed. The author will in no case be liable for any monetary damages >>> arising from such loss, damage or destruction. >>> >>> >>> >>> >>> On Thu, 7 Apr 2022 at 08:11, Bjørn Jørgensen <bjornjorgen...@gmail.com> >>> wrote: >>> >>>> >>>> 1. Where does S3 come into this >>>> >>>> He is processing data for each day at a time. So to dump each day to a >>>> fast storage he can use parquet files and write it to S3. >>>> >>>> ons. 6. apr. 2022 kl. 22:27 skrev Mich Talebzadeh < >>>> mich.talebza...@gmail.com>: >>>> >>>>> >>>>> Your statement below: >>>>> >>>>> I believe I have found the issue: the job writes data to hbase which >>>>> is on the same cluster. >>>>> When I keep on processing data and writing with spark to hbase , >>>>> eventually the garbage collection can not keep up anymore for hbase, and >>>>> the hbase memory consumption increases. As the clusters hosts both hbase >>>>> and spark, this leads to an overall increase and at some point you hit the >>>>> limit of the available memory on each worker. >>>>> I dont think the spark memory is increasing over time. >>>>> >>>>> >>>>> 1. Where is your cluster on Prem? Do you Have a Hadoop cluster >>>>> with spark using the same nodes as HDFS? >>>>> 2. Is your Hbase clustered or standalone and has been created on >>>>> HDFS nodes >>>>> 3. Are you writing to Hbase through phoenix or straight to HBase >>>>> 4. Where does S3 come into this >>>>> >>>>> >>>>> HTH >>>>> >>>>> >>>>> view my Linkedin profile >>>>> <https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.linkedin.com%2Fin%2Fmich-talebzadeh-ph-d-5205b2%2F&data=04%7C01%7Cjoris.billen%40bigindustries.be%7C7101a6f47bb1413e860e08da188c4712%7C49c3d703357947bfa8887c913fbdced9%7C0%7C0%7C637849288493392207%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=eiHW2%2FbI5kF91lzXlYhvJWilntztze4kNRcRvJj6IV4%3D&reserved=0> >>>>> >>>>> >>>>> https://en.everybodywiki.com/Mich_Talebzadeh >>>>> <https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fen.everybodywiki.com%2FMich_Talebzadeh&data=04%7C01%7Cjoris.billen%40bigindustries.be%7C7101a6f47bb1413e860e08da188c4712%7C49c3d703357947bfa8887c913fbdced9%7C0%7C0%7C637849288493392207%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=2kdSWdHDFiESyJ8WCc7YmH9XHUy%2BsNhSGGs%2Bq8LlvWI%3D&reserved=0> >>>>> >>>>> >>>>> *Disclaimer:* Use it at your own risk. Any and all responsibility for >>>>> any loss, damage or destruction of data or any other property which may >>>>> arise from relying on this email's technical content is explicitly >>>>> disclaimed. The author will in no case be liable for any monetary damages >>>>> arising from such loss, damage or destruction. >>>>> >>>>> >>>>> >>>>> >>>>> On Wed, 6 Apr 2022 at 16:41, Joris Billen < >>>>> joris.bil...@bigindustries.be> wrote: >>>>> >>>>>> HI, >>>>>> thanks for your reply. >>>>>> >>>>>> >>>>>> I believe I have found the issue: the job writes data to hbase which >>>>>> is on the same cluster. >>>>>> When I keep on processing data and writing with spark to hbase , >>>>>> eventually the garbage collection can not keep up anymore for hbase, and >>>>>> the hbase memory consumption increases. As the clusters hosts both hbase >>>>>> and spark, this leads to an overall increase and at some point you hit >>>>>> the >>>>>> limit of the available memory on each worker. >>>>>> I dont think the spark memory is increasing over time. >>>>>> >>>>>> >>>>>> >>>>>> Here more details: >>>>>> >>>>>> **Spark: 2.4 >>>>>> **operation: many spark sql statements followed by writing data to a >>>>>> nosql db from spark >>>>>> like this: >>>>>> df=read(fromhdfs) >>>>>> df2=spark.sql(using df 1) >>>>>> ..df10=spark.sql(using df9) >>>>>> spark.sql(CACHE TABLE df10) >>>>>> df11 =spark.sql(using df10) >>>>>> df11.write >>>>>> Df12 =spark.sql(using df10) >>>>>> df12.write >>>>>> df13 =spark.sql(using df10) >>>>>> df13.write >>>>>> **caching: yes one df that I will use to eventually write 3 x to a db >>>>>> (those 3 are different) >>>>>> **Loops: since I need to process several years, and processing 1 day >>>>>> is already a complex process (40 minutes on 9 node cluster running quite >>>>>> a >>>>>> bit of executors). So in the end it will do all at one go and there is a >>>>>> limit of how much data I can process in one go with the available >>>>>> resources. >>>>>> Some people here pointed out they believe this looping should not be >>>>>> necessary. But what is the alternative? >>>>>> —> Maybe I can write to disk somewhere in the middle, and read again >>>>>> from there so that in the end not all must happen in one go in memory. >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> On 5 Apr 2022, at 14:58, Gourav Sengupta <gourav.sengu...@gmail.com> >>>>>> wrote: >>>>>> >>>>>> Hi, >>>>>> >>>>>> can you please give details around: >>>>>> spark version, what is the operation that you are running, why in >>>>>> loops, and whether you are caching in any data or not, and whether you >>>>>> are >>>>>> referencing the variables to create them like in the following expression >>>>>> we are referencing x to create x, x = x + 1 >>>>>> >>>>>> Thanks and Regards, >>>>>> Gourav Sengupta >>>>>> >>>>>> On Mon, Apr 4, 2022 at 10:51 AM Joris Billen < >>>>>> joris.bil...@bigindustries.be> wrote: >>>>>> >>>>>>> Clear-probably not a good idea. >>>>>>> >>>>>>> But a previous comment said “you are doing everything in the end in >>>>>>> one go”. >>>>>>> So this made me wonder: in case your only action is a write in the >>>>>>> end after lots of complex transformations, then what is the alternative >>>>>>> for >>>>>>> writing in the end which means doing everything all at once in the end? >>>>>>> My >>>>>>> understanding is that if there is no need for an action earlier, you >>>>>>> will >>>>>>> do all at the end, which means there is a limitation to how many days >>>>>>> you >>>>>>> can process at once. And hence the solution is to loop over a couple >>>>>>> days, >>>>>>> and submit always the same spark job just for other input. >>>>>>> >>>>>>> >>>>>>> Thanks! >>>>>>> >>>>>>> On 1 Apr 2022, at 15:26, Sean Owen <sro...@gmail.com> wrote: >>>>>>> >>>>>>> This feels like premature optimization, and not clear it's >>>>>>> optimizing, but maybe. >>>>>>> Caching things that are used once is worse than not caching. It >>>>>>> looks like a straight-line through to the write, so I doubt caching >>>>>>> helps >>>>>>> anything here. >>>>>>> >>>>>>> On Fri, Apr 1, 2022 at 2:49 AM Joris Billen < >>>>>>> joris.bil...@bigindustries.be> wrote: >>>>>>> >>>>>>>> Hi, >>>>>>>> as said thanks for little discussion over mail. >>>>>>>> I understand that the action is triggered in the end at the write >>>>>>>> and then all of a sudden everything is executed at once. But I dont >>>>>>>> really >>>>>>>> need to trigger an action before. I am caching somewherew a df that >>>>>>>> will be >>>>>>>> reused several times (slightly updated pseudocode below). >>>>>>>> >>>>>>>> Question: is it then better practice to already trigger some >>>>>>>> actions on intermediate data frame (like df4 and df8), and cache >>>>>>>> them? So >>>>>>>> that these actions will not be that expensive yet, and the actions to >>>>>>>> write >>>>>>>> at the end will require less resources, which would allow to process >>>>>>>> more >>>>>>>> days in one go? LIke what is added in red in improvement section >>>>>>>> in the pseudo code below? >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> *pseudocode:* >>>>>>>> >>>>>>>> >>>>>>>> *loop over all days:* >>>>>>>> * spark submit 1 day* >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> with spark submit (overly simplified)= >>>>>>>> >>>>>>>> >>>>>>>> * df=spark.read(hfs://somepath)* >>>>>>>> * …* >>>>>>>> * ##IMPROVEMENT START* >>>>>>>> * df4=spark.sql(some stuff with df3)* >>>>>>>> * spark.sql(CACHE TABLE df4)* >>>>>>>> * …* >>>>>>>> * df8=spark.sql(some stuff with df7)* >>>>>>>> * spark.sql(CACHE TABLE df8)* >>>>>>>> * ##IMPROVEMENT END* >>>>>>>> * ...* >>>>>>>> * df12=df11.spark.sql(complex stufff)* >>>>>>>> * spark.sql(CACHE TABLE df10)* >>>>>>>> * ...* >>>>>>>> * df13=spark.sql( complex stuff with df12)* >>>>>>>> * df13.write * >>>>>>>> * df14=spark.sql( some other complex stuff with df12)* >>>>>>>> * df14.write * >>>>>>>> * df15=spark.sql( some completely other complex stuff with df12)* >>>>>>>> * df15.write * >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> THanks! >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On 31 Mar 2022, at 14:37, Sean Owen <sro...@gmail.com> wrote: >>>>>>>> >>>>>>>> If that is your loop unrolled, then you are not doing parts of work >>>>>>>> at a time. That will execute all operations in one go when the write >>>>>>>> finally happens. That's OK, but may be part of the problem. For >>>>>>>> example if >>>>>>>> you are filtering for a subset, processing, and unioning, then that is >>>>>>>> just >>>>>>>> a harder and slower way of applying the transformation to all data at >>>>>>>> once. >>>>>>>> >>>>>>>> On Thu, Mar 31, 2022 at 3:30 AM Joris Billen < >>>>>>>> joris.bil...@bigindustries.be> wrote: >>>>>>>> >>>>>>>>> Thanks for reply :-) >>>>>>>>> >>>>>>>>> I am using pyspark. Basicially my code (simplified is): >>>>>>>>> >>>>>>>>> df=spark.read.csv(hdfs://somehdfslocation) >>>>>>>>> df1=spark.sql (complex statement using df) >>>>>>>>> ... >>>>>>>>> dfx=spark.sql(complex statement using df x-1) >>>>>>>>> ... >>>>>>>>> dfx15.write() >>>>>>>>> >>>>>>>>> >>>>>>>>> What exactly is meant by "closing resources"? Is it just >>>>>>>>> unpersisting cached dataframes at the end and stopping the spark >>>>>>>>> context >>>>>>>>> explicitly: sc.stop()? >>>>>>>>> >>>>>>>>> >>>>>>>>> FOr processing many years at once versus a chunk in a loop: I see >>>>>>>>> that if I go up to certain number of days, one iteration will start >>>>>>>>> to have >>>>>>>>> tasks that fail. So I only take a limited number of days, and do this >>>>>>>>> process several times. Isnt this normal as you are always somehow >>>>>>>>> limited >>>>>>>>> in terms of resources (I have 9 nodes wiht 32GB). Or is it like this >>>>>>>>> that >>>>>>>>> in theory you could process any volume, in case you wait long enough? >>>>>>>>> I >>>>>>>>> guess spark can only break down the tasks up to a certain level >>>>>>>>> (based on >>>>>>>>> the datasets' and the intermediate results’ partitions) and at some >>>>>>>>> moment >>>>>>>>> you hit the limit where your resources are not sufficient anymore to >>>>>>>>> process such one task? Maybe you can tweak it a bit, but in the end >>>>>>>>> you’ll >>>>>>>>> hit a limit? >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> Concretely following topics would be interesting to find out more >>>>>>>>> about (links): >>>>>>>>> -where to see what you are still consuming after spark job ended >>>>>>>>> if you didnt close resources >>>>>>>>> -memory leaks for pyspark >>>>>>>>> -good article about closing resources (you find tons of snippets >>>>>>>>> on how to start spark context+ config for number/cores/memory of >>>>>>>>> worker/executors etc, but never saw a focus on making sure you clean >>>>>>>>> up —> >>>>>>>>> or is it just stopping the spark context) >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> On 30 Mar 2022, at 21:24, Bjørn Jørgensen < >>>>>>>>> bjornjorgen...@gmail.com> wrote: >>>>>>>>> >>>>>>>>> It`s quite impossible for anyone to answer your question about >>>>>>>>> what is eating your memory, without even knowing what language you are >>>>>>>>> using. >>>>>>>>> >>>>>>>>> If you are using C then it`s always pointers, that's the mem >>>>>>>>> issue. >>>>>>>>> If you are using python, there can be some like not using context >>>>>>>>> manager like With Context Managers and Python's with Statement >>>>>>>>> <https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Frealpython.com%2Fpython-with-statement%2F&data=04%7C01%7Cjoris.billen%40bigindustries.be%7C7101a6f47bb1413e860e08da188c4712%7C49c3d703357947bfa8887c913fbdced9%7C0%7C0%7C637849288493392207%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=O8Ad1rHnffmxTClWgleNF5YXO9yDq%2BEWhwKGdI4WQ6Q%3D&reserved=0> >>>>>>>>> >>>>>>>>> And another can be not to close resources after use. >>>>>>>>> >>>>>>>>> In my experience you can process 3 years or more of data, IF you >>>>>>>>> are closing opened resources. >>>>>>>>> I use the web GUI http://spark:4040 to follow what spark is >>>>>>>>> doing. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> ons. 30. mar. 2022 kl. 17:41 skrev Joris Billen < >>>>>>>>> joris.bil...@bigindustries.be>: >>>>>>>>> >>>>>>>>>> Thanks for answer-much appreciated! This forum is very useful >>>>>>>>>> :-) >>>>>>>>>> >>>>>>>>>> I didnt know the sparkcontext stays alive. I guess this is eating >>>>>>>>>> up memory. The eviction means that he knows that he should clear >>>>>>>>>> some of >>>>>>>>>> the old cached memory to be able to store new one. In case anyone >>>>>>>>>> has good >>>>>>>>>> articles about memory leaks I would be interested to read. >>>>>>>>>> I will try to add following lines at the end of my job (as I >>>>>>>>>> cached the table in spark sql): >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> *sqlContext.sql("UNCACHE TABLE mytableofinterest ")* >>>>>>>>>> *spark.stop()* >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Wrt looping: if I want to process 3 years of data, my modest >>>>>>>>>> cluster will never do it one go , I would expect? I have to break it >>>>>>>>>> down >>>>>>>>>> in smaller pieces and run that in a loop (1 day is already lots of >>>>>>>>>> data). >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Thanks! >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> On 30 Mar 2022, at 17:25, Sean Owen <sro...@gmail.com> wrote: >>>>>>>>>> >>>>>>>>>> The Spark context does not stop when a job does. It stops when >>>>>>>>>> you stop it. There could be many ways mem can leak. Caching maybe - >>>>>>>>>> but it >>>>>>>>>> will evict. You should be clearing caches when no longer needed. >>>>>>>>>> >>>>>>>>>> I would guess it is something else your program holds on to in >>>>>>>>>> its logic. >>>>>>>>>> >>>>>>>>>> Also consider not looping; there is probably a faster way to do >>>>>>>>>> it in one go. >>>>>>>>>> >>>>>>>>>> On Wed, Mar 30, 2022, 10:16 AM Joris Billen < >>>>>>>>>> joris.bil...@bigindustries.be> wrote: >>>>>>>>>> >>>>>>>>>>> Hi, >>>>>>>>>>> I have a pyspark job submitted through spark-submit that does >>>>>>>>>>> some heavy processing for 1 day of data. It runs with no errors. I >>>>>>>>>>> have to >>>>>>>>>>> loop over many days, so I run this spark job in a loop. I notice >>>>>>>>>>> after >>>>>>>>>>> couple executions the memory is increasing on all worker nodes and >>>>>>>>>>> eventually this leads to faillures. My job does some caching, but I >>>>>>>>>>> understand that when the job ends successfully, then the >>>>>>>>>>> sparkcontext is >>>>>>>>>>> destroyed and the cache should be cleared. However it seems that >>>>>>>>>>> something >>>>>>>>>>> keeps on filling the memory a bit more and more after each run. >>>>>>>>>>> THis is the >>>>>>>>>>> memory behaviour over time, which in the end will start leading to >>>>>>>>>>> failures >>>>>>>>>>> : >>>>>>>>>>> >>>>>>>>>>> (what we see is: green=physical memory used, green-blue=physical >>>>>>>>>>> memory cached, grey=memory capacity =straight line around 31GB ) >>>>>>>>>>> This runs on a healthy spark 2.4 and was optimized already to >>>>>>>>>>> come to a stable job in terms of spark-submit resources parameters >>>>>>>>>>> like >>>>>>>>>>> driver-memory/num-executors/executor-memory/executor-cores/spark.locality.wait). >>>>>>>>>>> Any clue how to “really” clear the memory in between jobs? So >>>>>>>>>>> basically currently I can loop 10x and then need to restart my >>>>>>>>>>> cluster so >>>>>>>>>>> all memory is cleared completely. >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> Thanks for any info! >>>>>>>>>>> >>>>>>>>>>> <Screenshot 2022-03-30 at 15.28.24.png> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>>> -- >>>>>>>>> Bjørn Jørgensen >>>>>>>>> Vestre Aspehaug 4, 6010 Ålesund >>>>>>>>> Norge >>>>>>>>> >>>>>>>>> +47 480 94 297 >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>> >>>> -- >>>> Bjørn Jørgensen >>>> Vestre Aspehaug 4, 6010 Ålesund >>>> Norge >>>> >>>> +47 480 94 297 >>>> >>> >>> > > -- > Bjørn Jørgensen > Vestre Aspehaug 4, 6010 Ålesund > Norge > > +47 480 94 297 > > >
