TechnitiumSoftware/DnsServer · error · InvalidOperationException

Cannot update record: the record does not exists to be updat

Error message

Cannot update record: the record does not exists to be updated.

What it means

Thrown by PrimarySubDomainZone.UpdateRecord when TryDeleteRecord(oldRecord.Type, oldRecord.RDATA) returns false — i.e., the exact old record is not present in the zone. UpdateRecord is a delete-then-add atomic pair, so the old record must exist verbatim. The guard raises InvalidOperationException ('does not exists' is a verbatim source typo) before adding the new record, leaving the zone unchanged.

Source

Thrown at DnsServerCore/Dns/Zones/PrimarySubDomainZone.cs:242

                case DnsResourceRecordType.DNSKEY:
                case DnsResourceRecordType.RRSIG:
                case DnsResourceRecordType.NSEC:
                case DnsResourceRecordType.NSEC3PARAM:
                case DnsResourceRecordType.NSEC3:
                    throw new InvalidOperationException("Cannot update DNSSEC records.");

                default:
                    if (oldRecord.Type != newRecord.Type)
                        throw new InvalidOperationException("Old and new record types do not match.");

                    if ((_primaryZone.DnssecStatus != AuthZoneDnssecStatus.Unsigned) && newRecord.GetAuthGenericRecordInfo().Disabled)
                        throw new DnsServerException("Cannot update record: disabling records in a signed zones is not supported.");

                    if (newRecord.OriginalTtlValue > _primaryZone.GetZoneSoaExpire())
                        throw new DnsServerException("Cannot update record: TTL cannot be greater than SOA EXPIRE.");

                    if (!TryDeleteRecord(oldRecord.Type, oldRecord.RDATA, out DnsResourceRecord deletedRecord))
                        throw new InvalidOperationException("Cannot update record: the record does not exists to be updated.");

                    AddRecord(newRecord, out IReadOnlyList<DnsResourceRecord> addedRecords, out IReadOnlyList<DnsResourceRecord> deletedRecords);

                    List<DnsResourceRecord> allDeletedRecords = new List<DnsResourceRecord>(deletedRecords.Count + 1);
                    allDeletedRecords.Add(deletedRecord);
                    allDeletedRecords.AddRange(deletedRecords);

                    _primaryZone.CommitAndIncrementSerial(allDeletedRecords, addedRecords);

                    if (_primaryZone.DnssecStatus != AuthZoneDnssecStatus.Unsigned)
                        _primaryZone.UpdateDnssecRecordsFor(this, oldRecord.Type);

                    _primaryZone.TriggerNotify();
                    break;
            }
        }

        #endregion

View on GitHub (pinned to d0484b6c1e)

Solutions

1. Re-read the current record from the zone and use it as 'old' before updating.
2. Use optimistic-concurrency: if the update fails with 'does not exist', reload and retry or report not-found.
3. Ensure the old record's RDATA matches the stored record exactly (case, wire format).

Example fix

// before
zone.UpdateRecord(staleOld, newRecord); // throws if gone

// after
if (!zone.TryGetRecords(oldRecord.Type, out var current)
    || !current.Any(r => r.RDATA.SequenceEqual(oldRecord.RDATA)))
    return; // record already gone; nothing to update
zone.UpdateRecord(oldRecord, newRecord);

if (!zone.TryGetRecords(oldRecord.Type, out var rrset)
    || !rrset.Any(r => r.RDATA.SequenceEqual(oldRecord.RDATA)))
    return; // already gone
zone.UpdateRecord(oldRecord, newRecord);

static bool RecordExists(IReadOnlyList<DnsResourceRecord> rrset, DnsResourceRecord oldR) =>
    rrset.Any(r => r.RDATA.SequenceEqual(oldR.RDATA));

try { zone.UpdateRecord(oldRecord, newRecord); }
catch (InvalidOperationException ex) when (ex.Message.Contains("does not exists"))
{ /* stale snapshot: reload and retry, or treat as no-op */ }

When it happens

Trigger: zone.UpdateRecord(old, new) where 'old' was already deleted, never existed, or whose RDATA does not byte-match the stored RRset.

Common situations: Stale 'old' snapshot read before a concurrent edit; race where another client deleted the record; comparing records by partial fields rather than full RDATA.

Related errors

• Cannot delete DNSSEC records.
• Cannot update record: use SetRecords() for {oldRecord.Type}
• Cannot update DNSSEC records.
• Old and new record types do not match.
• Cannot update record: disabling records in a signed zones is

AI-assisted analysis of TechnitiumSoftware/DnsServer@d0484b6c1e (2026-08-13). Data as JSON: /api/errors/bc8f862c7e67a1f1. Report an issue: GitHub.