[HDDS-8867] Datanode re-registration memory leak

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.4.0
• Component/s: SCM
• Labels: pull-request-available
• Target Version/s: 1.4.0, 1.3.1
• Assignee: Attila Doroszlai
• Reporter: Attila Doroszlai
• Created: 16/Jun/23 07:02
• Updated: 27/Jun/23 19:43
• Resolved: 17/Jun/23 13:21

Description

SCM does not properly remove datanode address to UUID mapping for the old address when datanode re-registers with different address. It tries to remove dnsName (address) from the set of UUIDs:

https://github.com/apache/ozone/blob/3846cd249d10a6f7d937853be0f97c848d9ea6a6/hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/node/SCMNodeManager.java#L481-L492

  private synchronized void removeEntryFromDnsToUuidMap(String dnsName) {
    if (!dnsToUuidMap.containsKey(dnsName)) {
      return;
    }
    Set<String> dnSet = dnsToUuidMap.get(dnsName);
    if (dnSet.contains(dnsName)) {
      dnSet.remove(dnsName);
    }
    if (dnSet.isEmpty()) {
      dnsToUuidMap.remove(dnsName);
    }
  }

Issue Links

• links to: GitHub Pull Request #4916