The parameter column_families in the LDBTool::Run function did not take effect.

[dongdongwcpp]

The parameter column_families in the LDBTool::Run function did not take effect while using a custom Comparator or other custom scenarios:

void LDBTool::Run(int argc, char** argv, Options options,
                  const LDBOptions& ldb_options,
                  const std::vector<ColumnFamilyDescriptor>* column_families) 
LDBTool tool;
tool.Run(argc, argv, rocksdb::Options(), LDBOptions(), &column_families);

which seems to be a problem. This issue still exists in the latest version of RocksDB.

Expected behavior

when using a custom Comparator to open rocksdb,The function LDBTool::run should set std::vector column_families to ldb tool, and should work fine to admin the database.

Actual behavior

root$ ../build/tools/ldb   --db=./testdb drop_column_family new_cf
Failed: Invalid argument: leveldb.BytewiseComparator: does not match existing comparator my_comparator

Steps to reproduce the behavior

#include <rocksdb/db.h>
#include <rocksdb/options.h>
#include "rocksdb/ldb_tool.h"

using namespace rocksdb;
class MyComparator : public rocksdb::Comparator {
 public:
  int Compare(const rocksdb::Slice& a, const rocksdb::Slice& b) const override {
    return a.compare(b);
  }
  virtual void FindShortSuccessor(std::string* key) const {}
  virtual void FindShortestSeparator(std::string* start, const Slice& limit) const {}
  const char* Name() const override { return "my_comparator"; }
};

int main(int argc, char** argv) {
  rocksdb::DB* db;
  rocksdb::Options options;
  options.create_if_missing = true;
  options.create_missing_column_families = true;
  rocksdb::ColumnFamilyOptions cf_options;

  cf_options.comparator = new MyComparator;
  // create column family with custom comparator
  std::vector<rocksdb::ColumnFamilyDescriptor> column_families = {
      rocksdb::ColumnFamilyDescriptor(rocksdb::kDefaultColumnFamilyName,cf_options),
      rocksdb::ColumnFamilyDescriptor("new_cf", cf_options),
  };

  if (argc > 2) {
    LDBTool tool;
    tool.Run(argc, argv, rocksdb::Options(), LDBOptions(), &column_families);
    return 0;
  }

  std::vector<ColumnFamilyHandle*> handles;
  rocksdb::DB::Open(options, "./testdb", column_families, &handles, &db);
  db->Put(rocksdb::WriteOptions(), "key1", "value1");
  delete db;
  return 0;
}

compile and run:

g++ --std=c++11 my_comparator.cc -o ldb_test  -I ../include ../build_release/librocksdb.a -lpthread 
#run to create db with two cf
./ldb_test
#run to drop new_cf and got failed
./ldb_test --db=./testdb drop_column_family new_cf
Failed: Invalid argument: leveldb.BytewiseComparator: does not match existing comparator my_comparator

how to fix

set column_families for command here:

rocksdb/tools/ldb_cmd.cc

Line 200 in 15053f3

command->SetLDBOptions(ldb_options);

I may try to fix it if it's a real issue.

[ajkr]

I may try to fix it if it's a real issue.

Looks like a real issue to me

[cz2h]

Hi @dongdongwcpp, @ajkr , may I take this issue if you are not currently working on it?

[ajkr]

I think it has been long enough since the last update to assume nobody is working on it. Just make sure to confirm the provided instructions still repro the bug, as there's a chance somebody fixed it without closing the issue.

[ajkr]

Fixed by #12261