Hi Stephan, Since we use our own FRocksDB instead of the original RocksDB as dependency, I am not sure whether this problem has relationship with this. From my knowledge, more customers would include Flink classes within the application jar package, and it might cause problems if the client has different flink version with servers.
Best, Yun Tang ________________________________ From: Stephan Ewen <se...@apache.org> Sent: Wednesday, August 4, 2021 19:10 To: Yun Tang <myas...@live.com> Cc: Sandeep khanzode <sand...@shiftright.ai>; user <user@flink.apache.org> Subject: Re: Bloom Filter - RocksDB - LinkageError Classloading @Yun Tang Does it make sense to add RocksDB to the "always parent-first options" to avoid these kind of errors when users package apps incorrectly? My feeling is that these packaging errors occur very frequently. On Wed, Aug 4, 2021 at 10:41 AM Yun Tang <myas...@live.com<mailto:myas...@live.com>> wrote: Hi Sandeep, Did you include the RocksDB classes in the application jar package? You can unpark your jar package to check whether them existed. If so, since RocksDB classes are already included in the flink-dist package, you don't need to include them in your jar package (maybe you explicitly added the dependency of org.rocksdb:rocksdbjni in your pom). Best Yun Tang ________________________________ From: Sandeep khanzode <sand...@shiftright.ai<mailto:sand...@shiftright.ai>> Sent: Wednesday, August 4, 2021 11:54 To: user <user@flink.apache.org<mailto:user@flink.apache.org>> Subject: Bloom Filter - RocksDB - LinkageError Classloading Hello, I tried to add the bloom filter functionality as mentioned here: https://ci.apache.org/projects/flink/flink-docs-release-1.11/api/java/org/apache/flink/contrib/streaming/state/RocksDBOptionsFactory.html rocksDbBackend.setRocksDBOptions(new RocksDBOptionsFactory() { public DBOptions createDBOptions(DBOptions currentOptions, Collection<AutoCloseable> handlesToClose) { return currentOptions.setMaxOpenFiles(1024); } public ColumnFamilyOptions createColumnOptions(ColumnFamilyOptions currentOptions, Collection<AutoCloseable> handlesToClose) { BloomFilter bloomFilter = new BloomFilter(); handlesToClose.add(bloomFilter); return currentOptions .setTableFormatConfig( new BlockBasedTableConfig().setFilter(bloomFilter)); } }); This is in the main class where we setup in the StreamExecutionEnvironment … I get ClassLoading errors due to that ... Caused by: java.lang.LinkageError: loader constraint violation: loader org.apache.flink.util.ChildFirstClassLoader @1169afe1 wants to load class org.rocksdb.ColumnFamilyOptions. A different class with the same name was previously loaded by 'app'. (org.rocksdb.ColumnFamilyOptions is in unnamed module of loader 'app') What is documented is to change the order to parent-first in the flink-conf.yaml … but then I get different issues for the basic/core Spring Framework classes not being serializable … Any help will be appreciated. Thanks, Sandip
