Siyao Meng created HDDS-17144:
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Summary: ozone repair tools fail to load RocksDB OPTIONS written
by a newer RocksDB version
Key: HDDS-17144
URL: https://issues.apache.org/jira/browse/HDDS-17144
Project: Apache Ozone
Issue Type: Bug
Components: Tools
Reporter: Siyao Meng
h3. Problem
{{ManagedRocksDB#openWithLatestOptions}} calls
{{OptionsUtil.loadLatestOptions}} with a default {{ManagedConfigOptions}}, so
{{ignore_unknown_options}} is false. It is used by:
* {{ozone repair om|scm update-transaction}} ({{TransactionInfoRepair}})
* {{ozone repair ldb compact}} ({{RocksDBManualCompaction}})
* {{ozone repair om snapshot chain}} ({{SnapshotChainRepair}})
When the DB was last opened by a newer RocksDB, these tools fail before opening
the DB. That happens after a downgrade before finalization, or when an older
CLI runs against a newer DB. Reproduced:
||DB written by||Loaded by||Result||
|10.10.1.1 (master)|7.7.3 (2.2.x)|{{Could not find option: :
metadata_write_temperature}}|
|11.8.1|10.10.1.1|{{Extra option not recognized: async_wal_precreate}}|
|either|either, with ignore_unknown_options=true|loads and opens|
This hits exactly when a repair is needed: the downgraded service does not
start, so it has not yet rewritten the OPTIONS file in the old format.
h3. Proposal
Set {{setIgnoreUnknownOptions(true)}} in {{openWithLatestOptions}}. This is
safe:
* RocksDB honours the flag only for OPTIONS files written by a newer RocksDB
version. For same-version or older files, unknown options still fail as
corruption ({{options_parser.cc}}, {{ConfigOptions::ignore_unknown_options}}
docs).
* RocksDB's own {{ldb}} exposes {{--ignore_unknown_options}} for the same
reason.
* Whether the data is readable is still enforced independently by the SST and
MANIFEST readers.
When the older tool opens the DB, RocksDB writes a new OPTIONS file in the
older format and keeps the previous one. Ozone services never load the DB's
OPTIONS file; they build options from {{DBProfile}}, the ini file and the
config. So nothing the services rely on is lost.
Keep {{DBConfigFromFile}} strict: those ini files are written by users, and a
typo should still fail.
h3. Test
Rewrite a DB's OPTIONS file with {{rocksdb_version=99.0.0}} plus an extra
unknown CF option, and check that {{openWithLatestOptions}} succeeds. With the
original version header, it must still fail.
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