Fix compaction error when upgrading from RocksDB v5.10.3 to v8.11.4

[dgpp-programer]

When I upgraded RocksDB from version v5.10.1 to v8.11.4, a compaction error occurred:
2025/12/19-08:41:47.105378 139671781758720 [WARN] [db/compaction/compaction_job.cc:848] [default] [JOB 6] Compaction Total number of input records: 44912, but processed 44911 records.
The root cause of this issue is that the SST metadata in RocksDB v5.10.3 does not include the num_range_deletion field, whereas this field was added in v8.11.4 with a default value of 0.
After the upgrade, when compaction reads the metadata of legacy SST files, it fails to retrieve the num_range_deletions value and thus assigns it a default of 0. However, these legacy SST files actually contain DeleteRange operations.
Upon completion of compaction, a validation check is performed:
// rocksdb-8.11.4/db/compaction/compaction_job.cc uint64_t expected = compaction_stats_.stats.num_input_records - num_input_range_del; uint64_t actual = compaction_job_stats_->num_input_records; if (expected != actual) { xxx // error
Since num_range_deletion is assigned a value of 0, this validation check fails.

Reproduction code as follows:
Generate data directory with v5.10.3:
int main() { Options options; options.create_if_missing = true; DB* db; Status s = DB::Open(options, "../db", &db); assert(s.ok()); auto generate_sst = [&]() { for (int i = 0; i < 100; ++i) { string key = "key" + to_string(i); string value = "value" + to_string(i); s = db->Put(WriteOptions(), key, value); assert(s.ok()); } s = db->DeleteRange(WriteOptions(), db->DefaultColumnFamily(), "key3", "key8"); assert(s.ok()); s = db->Flush(FlushOptions()); assert(s.ok()); }; // generate 2 sst files generate_sst(); generate_sst(); delete db; return 0; }
Upgrade and verify with v8.11.4:
int main() { DB* db; Options options; options.create_if_missing = true; Status status = DB::Open(options, "../db/", &db); if (!status.ok()) { std::cout << "open db failed: " << status.ToString() << std::endl; return -1; } status = db->CompactRange(CompactRangeOptions(), nullptr, nullptr); if (!status.ok()) { std::cout << "compact db failed: " << status.ToString() << std::endl; return -1; } delete db; return 0; }
// will print
compact db failed: Corruption: Compaction number of input keys does not match number of keys processed. Expected 92 but processed 90. Compaction summary: Base version 2 Base level 0, inputs: [10(1881B) 7(1881B)]

The fix approach is as follows: when num_range_deletions is 0, check whether there are fragmented_range_dels. If fragmented_range_dels exist, throw an error and skip the validation check following the original process.

[dgpp-programer]

Hi maintainers, could you please review and approve the workflow for this PR? Thanks! @ajkr @pdillinger