Hi,
Using Bitcoin Core RPC client version v0.17.0.1-g1476554d3b1db5352c0de1de7524864d4bce3aac

I'm using bitcoin-cli loadwallet and unloadwallet commands. They both seem to work fine.
Unfortunately, memory is getting higher and higher, and no wallet can be loaded after 300 have been.
The problem may be related to BerkeleyDB rather than to Bitcoin Core itself. Fact is that lsof shows handles not cleared off after the unloadwallet command is issued. Files still handled are .walletlock, db.log and database/log.0000000001 .
When 300 different wallets have been loaded/unloaded, used RAM is over 8 GB, and bitcoind will finally become unstable and fail.

Any help would be appreciated.
Regards,
LOCK(cs_args);
        m_available_args.clear();
    }
    /**
     * Get the help string
     */
    std::string GetHelpMessage() const;
    /**
     * Check whether we know of this arg
     */
    bool IsArgKnown(const std::string& key) const;
};
extern ArgsManager gArgs;
/**
 * @return true if help has been requested via a command-line arg
 */
bool HelpRequested(const ArgsManager& args);
/**
 * Format a string to be used as group of options in help messages
 *
 * @param message Group name (e.g. "RPC server options:")
 * @return the formatted string
 */
std::string HelpMessageGroup(const std::string& message);
/**