> Are you sure about that? Or do you refer to "libhdfs can be used in > threaded applications using the Posix Threads" from their doc? Which > means something different (libhdfs is thread safe, given that the > global functions are called correctly.).
libdhfs is thread safe. Concurrency and Hadoop FS "handles" The Hadoop FS implementation includes a FS handle cache which caches based on the URI of the namenode along with the user connecting. So, all calls to hdfsConnect will return the same handle but calls to hdfsConnectAsUser with different users will return different handles. But, since HDFS client handles are completely thread safe, this has no bearing on concurrency. Concurrency and libhdfs/JNI The libhdfs calls to JNI should always be creating thread local storage, so (in theory), libhdfs should be as thread safe as the underlying calls to the Hadoop FS. http://hadoop.apache.org/docs/r2.2.0/hadoop-project-dist/hadoop-hdfs/LibHdfs.html
