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.
if (gArgs.GetBoolArg("-stopafterblockimport", DEFAULT_STOPAFTERBLOCKIMPORT)) {
        LogPrintf("Stopping after block import\n");
        StartShutdown();
        return;
    }
    } 
    if (gArgs.GetArg("-persistmempool", DEFAULT_PERSIST_MEMPOOL)) {
        LoadMempool();
    }
    g_is_mempool_loaded = !ShutdownRequested();
}
/** Sanity checks
 *  Ensure that Bitcoin is running in a usable environment with all
 *  necessary library support.
 */
static bool InitSanityCheck()
{
    if(!ECC_InitSanityCheck()) {
        InitError("Elliptic curve cryptography sanity check failure. Aborting.");
        return false;
    }
    if (!glibc_sanity_test() || !glibcxx_sanity_test())
        return false;
    if (!Random_SanityCheck()) {
        InitError("OS cryptographic RNG sanity check failure. Aborting.");
        return false;
    }
    return true;
}
static bool AppInitServers()