EDITED 2019-02-08

`maxTxFee` is a global variable, used by both the raw transaction and wallet RPCs. It's set from `-maxtxfee`.

~listed in the global help text in init.cpp, but is only set in `WalletInit::ParameterInteraction()`. If the wallet is disabled, then `-maxtxfee` is ignored and the default is used.~

~This behaviour has existed since the mempool was changed to limit acceptance based on `maxTxFee` in https://github.com/bitcoin/bitcoin/commit/fa331db68bcc68e4c93fb45aaa30f911b0ecfe1a.~

~Short-term fix is to move the `-maxtxfee` handling to `InitParameterInteraction()` in init.cpp.~
EDIT: `maxTxFee` initiation bug fixed in #15357 

I don't think we should share this setting between the node and wallet.
{
    const CChainParams& chainparams = Params();
    
#ifndef WIN32
    CreatePidFile(GetPidFile(), getpid());
#endif
    if (LogInstance().m_print_to_file) {
        if (gArgs.GetBoolArg("-shrinkdebugfile", LogInstance().DefaultShrinkDebugFile())) {
            
            
            LogInstance().ShrinkDebugFile();
        }
        if (!LogInstance().OpenDebugLog()) {
            return InitError(strprintf("Could not open debug log file %s",
                LogInstance().m_file_path.string()));
        }
    }
    if (!LogInstance().m_log_timestamps)
        LogPrintf("Startup time: %s\n", FormatISO8601DateTime(GetTime()));
    LogPrintf("Default data directory %s\n", GetDefaultDataDir().string());
    LogPrintf("Using data directory %s\n", GetDataDir().string());
    
    fs::path config_file_path = GetConfigFile(gArgs.GetArg("-conf", BITCOIN_CONF_FILENAME));