EIO

EIO

Error message

fuseConnectAsThreadUid: failed to open a libhdfs connection!  error %d.

What it means

Error "fuseConnectAsThreadUid: failed to open a libhdfs connection! error %d. " thrown in apache/hadoop.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/fuse-dfs/fuse_impls_chown.c:66

    user = getUsername(uid);
    if (NULL == user) {
      ERROR("Could not lookup the user id string %d",(int)uid);
      ret = -EIO;
      goto cleanup;
    }
  }
  if (gid != -1) {
    group = getGroup(gid);
    if (group == NULL) {
      ERROR("Could not lookup the group id string %d",(int)gid);
      ret = -EIO;
      goto cleanup;
    }
  }

  ret = fuseConnectAsThreadUid(&conn);
  if (ret) {
    fprintf(stderr, "fuseConnectAsThreadUid: failed to open a libhdfs "
            "connection!  error %d.\n", ret);
    ret = -EIO;
    goto cleanup;
  }

  if (hdfsChown(hdfsConnGetFs(conn), path, user, group)) {
    ret = errno;
    ERROR("Could not chown %s to %d:%d: error %d", path, (int)uid, gid, ret);
    ret = (ret > 0) ? -ret : -EIO;
    goto cleanup;
  }

cleanup:
  if (conn) {
    hdfsConnRelease(conn);
  }
  free(user);
  free(group);

View on GitHub (pinned to 2add963021)

Solutions

Verify the user's Kerberos ticket is valid (kinit) and that libhdfs can connect to the NameNode; then retry the chown operation.
Check the error code to distinguish authentication failure from configuration problems (CLASSPATH/HADOOP_CONF_DIR).

When it happens

Trigger: Thrown at hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/fuse-dfs/fuse_impls_chown.c:66 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/20626404053158fc. Report an issue: GitHub.