apache/hadoop · error · PartialGroupNameException

failed to get group id list for user '" + userName + "'

Error message

failed to get group id list for user '" + userName + "'

What it means

During partial group resolution Hadoop runs a second shell command (an 'id -G' style helper) to fetch the user's group ids. If that command executes but exits non-zero (ExitCodeException), resolution is abandoned and PartialGroupNameException('failed to get group id list for user X') wraps it. Unlike unresolvable names, a non-zero exit is treated as a broken environment, not partial data.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/ShellBasedUnixGroupsMapping.java:305

      throw new PartialGroupNameException("Does not support partial group"
      + " name resolution on Windows. " + errMessage);
    }
    if (groupNames.isEmpty()) {
      throw new PartialGroupNameException("The user name '" + userName
          + "' is not found. " + errMessage);
    } else {
      LOG.warn("Some group names for '{}' are not resolvable. {}",
          userName, errMessage);
      // attempt to partially resolve group names
      ShellCommandExecutor partialResolver = createGroupIDExecutor(userName);
      try {
        partialResolver.execute();
        return parsePartialGroupNames(
            groupNames, partialResolver.getOutput());
      } catch (ExitCodeException ece) {
        // If exception is thrown trying to get group id list,
        // something is terribly wrong, so give up.
        throw new PartialGroupNameException(
            "failed to get group id list for user '" + userName + "'", ece);
      } catch (IOException ioe) {
        String message =
            "Can't execute the shell command to " +
            "get the list of group id for user '" + userName + "'";
        if (partialResolver.isTimedOut()) {
          message +=
              " because of the command taking longer than " +
              "the configured timeout: " + timeout + " seconds";
        }
        throw new PartialGroupNameException(message, ioe);
      }
    }
  }

  /**
   * Split group names into a set.
   *

View on GitHub (pinned to 2add963021)

Solutions

1. Run 'id -G <user>' as the Hadoop service user on the mapping node and reproduce the failure
2. Inspect the nested ExitCodeException for the helper's stderr
3. Repair the name-service backend (sssd/nscd/LDAP connectivity and permissions)
4. If intermittent under load, tune group mapping cache settings (hadoop.security.group.mapping.*.cache secs) to reduce lookup pressure

try {
  groups = mapping.getGroups(user);
} catch (PartialGroupNameException e) {
  if (e.getMessage().startsWith("failed to get group id list")) {
    // nested ExitCodeException holds helper stderr: inspect it, check NSS/LDAP health
  }
  throw e;
}

When it happens

Trigger: The group-id helper command fails with a non-zero exit on the mapping host: the user vanished between lookups, NSS/PAM errors, permission denied reading the group database, or the backend directory rejecting the query.

Common situations: Broken sssd/nscd configurations, LDAP servers rate-limiting or failing, users deleted while sessions are active.

Related errors

• Can't execute the shell command to get the list of group id
• Can't parse " + mapName + " list entry:" + line
• No such group:" + group
• Number of group names and ids do not match. group name =" +
• The user name '" + userName + "' is not found. " + errMessag

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/0e0ffac5b3ba786e. Report an issue: GitHub.