Known Issues in HDFS
This topic describes known issues and unsupported features for using HDFS in this release of Cloudera Runtime.
- CDPD-2946: Slow reading and writing of erasure-coded files
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The ISA-L library is not packaged with HDFS as a result of which HDFS erasure coding falls back to the Java implementation which is much slower than the native Hadoop implementation. This slows down the reading and writing of erasure-coded files.
- Unsupported Features
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The following HDFS features are currently not supported in Cloudera Data Platform:
- ACLs for the NFS gateway (HADOOP-11004)
- Aliyun Cloud Connector (HADOOP-12756)
- Allow HDFS block replicas to be provided by an external storage system (HDFS-9806)
- Consistent standby Serving reads (HDFS-12943)
- Cost-Based RPC FairCallQueue (HDFS-14403)
- HDFS Router Based Federation (HDFS-10467)
- More than two NameNodes (HDFS-6440)
- NameNode Federation (HDFS-1052)
- NameNode Port-based Selective Encryption (HDFS-13541)
- Non-Volatile Storage Class Memory (SCM) in HDFS Cache Directives (HDFS-13762)
- OpenStack Swift (HADOOP-8545)
- SFTP FileSystem (HADOOP-5732)
- Storage policy satisfier (HDFS-10285)
Technical Service Bulletins
- TSB 2021-406: CVE-2020-9492 Hadoop filesystem bindings (ie: webhdfs) allows credential stealing
- WebHDFS clients might send SPNEGO authorization header to remote URL without proper verification. A maliciously crafted request can trigger services to send server credentials to a webhdfs path (ie: webhdfs://…) for capturing the service principal.
- Knowledge article
- For the latest update on this issue see the corresponding Knowledge article: TSB-2021 406: CVE-2020-9492 Hadoop filesystem bindings (ie: webhdfs) allows credential stealing
