I've come across a similar issue before, the reason is that for a dynamic link library(so/dll), the there can only be one classloader to load it. When restart/failover happens in flink, the JVM will not exit but only create a new classloader which leads to multiple loading to the same so/dll, here same so/dll means the full path of a so/dll , unless the previous classloader has been garbage collected.
So here comes the solution 1. load a new so/dll, you can rename the so file, change the path of so, this is how flink rocksdb stateback works. 2. try using a fixed classloader Hegde, Mahendra <mahendra.he...@arity.com> 于2019年12月20日周五 下午2:19写道： > Hello Team, > > > > I am trying to use timezone finding service ( > https://github.com/dustin-johnson/timezonemap) in my Flink java job. It > worked fine in local machine and it worked fine initially in Flink server, > but after 2-3 restart of the job it started giving NoClassDefFoundError > error- > > > > java.lang.NoClassDefFoundError: Could not initialize class > com.github.luben.zstd.ZstdInputStream > > at > org.apache.commons.compress.compressors.zstandard.ZstdCompressorInputStream.<init>(ZstdCompressorInputStream.java:43) > > at > us.dustinj.timezonemap.data.DataLocator.getDataInputStream(DataLocator.java:22) > > at > us.dustinj.timezonemap.TimeZoneMap.forRegion(TimeZoneMap.java:92) > > at > us.dustinj.timezonemap.TimeZoneMap.forEverywhere(TimeZoneMap.java:60) > > at > dtap.service.TimezoneService.<init>(TimezoneService.java:17) > > at > functions.processors.KernelIntgrationProcessor.processElement(KernelIntgrationProcessor.java:47) > > at > functions.processors.KernelIntgrationProcessor.processElement(KernelIntgrationProcessor.java:23) > > at > org.apache.flink.streaming.api.operators.ProcessOperator.processElement(ProcessOperator.java:66) > > at > org.apache.flink.streaming.runtime.io.StreamInputProcessor.processInput(StreamInputProcessor.java:202) > > at > org.apache.flink.streaming.runtime.tasks.OneInputStreamTask.run(OneInputStreamTask.java:105) > > at > org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:300) > > at > org.apache.flink.runtime.taskmanager.Task.run(Task.java:704) > > at java.lang.Thread.run(Thread.java:748) > > > > > > When I looked at the code of ZstdCompressorInputStream class, it is > loading native libraries. And I found from below page that native library > unloading issue could be the reason for this. > > > https://www.ibm.com/support/knowledgecenter/SS7K4U_8.5.5/com.ibm.websphere.zseries.doc/ae/rtrb_classload_viewer.html > > Does anyone has faced similar issue or has idea to solve this problem? > > > > Thanks, > > Mahendra > > >
