apache/hadoop · error · IOException

<pool> found without <mode>

Error message

<pool> found without <mode>

What it means

Error "<pool> found without <mode>" thrown in apache/hadoop.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/OfflineImageReconstructor.java:1147

      if (poolName == null) {
        throw new IOException("<pool> found without <poolName>");
      }
      bld.setPoolName(poolName);
      String ownerName =
          pool.removeChildStr(CACHE_MANAGER_SECTION_OWNER_NAME);
      if (ownerName == null) {
        throw new IOException("<pool> found without <ownerName>");
      }
      bld.setOwnerName(ownerName);
      String groupName =
          pool.removeChildStr(CACHE_MANAGER_SECTION_GROUP_NAME);
      if (groupName == null) {
        throw new IOException("<pool> found without <groupName>");
      }
      bld.setGroupName(groupName);
      Integer mode = pool.removeChildInt(CACHE_MANAGER_SECTION_MODE);
      if (mode == null) {
        throw new IOException("<pool> found without <mode>");
      }
      bld.setMode(mode);
      Long limit = pool.removeChildLong(CACHE_MANAGER_SECTION_LIMIT);
      if (limit == null) {
        throw new IOException("<pool> found without <limit>");
      }
      bld.setLimit(limit);
      Long maxRelativeExpiry =
          pool.removeChildLong(CACHE_MANAGER_SECTION_MAX_RELATIVE_EXPIRY);
      if (maxRelativeExpiry == null) {
        throw new IOException("<pool> found without <maxRelativeExpiry>");
      }
      bld.setMaxRelativeExpiry(maxRelativeExpiry);
      pool.verifyNoRemainingKeys("pool");
      bld.build().writeDelimitedTo(out);
    }

    private void processDirectiveXml(Node directive) throws IOException {

View on GitHub (pinned to 2add963021)

Solutions

1. Add the missing <mode> element to the <pool> stanza in the fsimage XML.
2. Regenerate the fsimage XML with 'hdfs oiv' from a valid fsimage.

When it happens

Trigger: Thrown by oiv -r when a <pool> stanza lacks the mandatory <mode> element.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/60ae844d06f6a284. Report an issue: GitHub.