private void initAndLoad(final ConfigurationManager confManager) throws DatabaseException, IOException {
        this.hasLoadFirstLogIndex = false;
        this.firstLogIndex = 1;
        openDatabase();
        load(confManager);
    }
First log index and last log index key in configuration column family.
jraft-extension/bdb-log-storage-impl/src/main/java/com/alipay/sofa/jraft/storage/impl/BDBLogStorage.java