> It looks like `writer.setLength(0)` may actually allocate a new buffer, and then the buffer may also need to be resized as the String grows, so you could be creating a lot of orphaned buffers very quickly. I'm not that familiar with StringBuilder, is there a way to reset it and re-use the existing capacity? Maybe `writer.delete(0, writer.length())` [1]?
If I'm understanding Talat's logic correctly, it's not necessary to reuse the string builder at all in this case. On Wed, Sep 2, 2020 at 3:11 PM Brian Hulette <bhule...@google.com> wrote: > That error isn't exactly an OOM, it indicates the JVM is spending a > significant amount of time in garbage collection. > > It looks like `writer.setLength(0)` may actually allocate a new buffer, > and then the buffer may also need to be resized as the String grows, so you > could be creating a lot of orphaned buffers very quickly. I'm not that > familiar with StringBuilder, is there a way to reset it and re-use the > existing capacity? Maybe `writer.delete(0, writer.length())` [1]? > > [1] > https://stackoverflow.com/questions/242438/is-it-better-to-reuse-a-stringbuilder-in-a-loop > > On Wed, Sep 2, 2020 at 3:02 PM Talat Uyarer <tuya...@paloaltonetworks.com> > wrote: > >> Sorry for the wrong import. You can see on the code I am using >> StringBuilder. >> >> On Wed, Sep 2, 2020 at 2:55 PM Ning Kang <ni...@google.com> wrote: >> >>> Here is a question answered on StackOverflow: >>> https://stackoverflow.com/questions/27221292/when-should-i-use-javas-stringwriter >>> <https://urldefense.proofpoint.com/v2/url?u=https-3A__stackoverflow.com_questions_27221292_when-2Dshould-2Di-2Duse-2Djavas-2Dstringwriter&d=DwMFaQ&c=V9IgWpI5PvzTw83UyHGVSoW3Uc1MFWe5J8PTfkrzVSo&r=BkW1L6EF7ergAVYDXCo-3Vwkpy6qjsWAz7_GD7pAR8g&m=mVBqxC5kNOARPduF-c17S1VnIw8gwS6alvgONJKfheY&s=ggveahdPKo3vaAhADvjz4ucjndSmzyOZ8FPBvJ_0oZQ&e=> >>> >>> Could you try using StringBuilder instead since the usage is not >>> appropriate for a StringWriter? >>> >>> >>> On Wed, Sep 2, 2020 at 2:49 PM Talat Uyarer < >>> tuya...@paloaltonetworks.com> wrote: >>> >>>> Hi, >>>> >>>> I have an issue with String Concatenating. You can see my code >>>> below.[1] I have a step on my df job which is concatenating strings. But >>>> somehow when I use that step my job starts getting jvm restart errors. >>>> >>>> Shutting down JVM after 8 consecutive periods of measured GC >>>>> thrashing. Memory is used/total/max = 4112/5994/5994 MB, GC last/max = >>>>> 97.36/97.36 %, #pushbacks=3, gc thrashing=true. Heap dump not written. >>>> >>>> >>>> And also I try to use Avro rather than String. When I use Avro, it >>>> works fine without any issue. Do you have any suggestions? >>>> >>>> Thanks >>>> >>>> [1] https://dpaste.com/7RTV86WQC >>>> <https://urldefense.proofpoint.com/v2/url?u=https-3A__dpaste.com_7RTV86WQC&d=DwMFaQ&c=V9IgWpI5PvzTw83UyHGVSoW3Uc1MFWe5J8PTfkrzVSo&r=BkW1L6EF7ergAVYDXCo-3Vwkpy6qjsWAz7_GD7pAR8g&m=mVBqxC5kNOARPduF-c17S1VnIw8gwS6alvgONJKfheY&s=eSd0NcP8fw5BOZlSXtUMRfYuGWlN-gcXENVwgCmrapY&e=> >>>> >>>> >>>>
