view auto/module @ 7281:bd6563e81cea

Limit req: improved handling of negative times. Negative times can appear since workers only update time on an event loop iteration start. If a worker was blocked for a long time during an event loop iteration, it is possible that another worker already updated the time stored in the node. As such, time since last update of the node (ms) will be negative. Previous code used ngx_abs(ms) in the calculations. That is, negative times were effectively treated as positive ones. As a result, it was not possible to maintain high request rates, where the same node can be updated multiple times from during an event loop iteration. In particular, this affected setups with many SSL handshakes, see http://mailman.nginx.org/pipermail/nginx/2018-May/056291.html. Fix is to only update the last update time stored in the node if the new time is larger than previously stored one. If a future time is stored in the node, we preserve this time as is. To prevent breaking things on platforms without monotonic time available if system time is updated backwards, a safety limit of 60 seconds is used. If the time stored in the node is more than 60 seconds in the future, we assume that the time was changed backwards and update lr->last to the current time.
author Maxim Dounin <mdounin@mdounin.ru>
date Wed, 30 May 2018 15:40:34 +0300
parents 2c7a2d75938a
children 4b1299b1856a
line wrap: on
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# Copyright (C) Ruslan Ermilov
# Copyright (C) Nginx, Inc.


case $ngx_module_type in
    HTTP_*) ngx_var=HTTP ;;
    *)      ngx_var=$ngx_module_type ;;
esac


if [ "$ngx_module_link" = DYNAMIC ]; then

    for ngx_module in $ngx_module_name; do
        # extract the first name
        break
    done

    DYNAMIC_MODULES="$DYNAMIC_MODULES $ngx_module"
    eval ${ngx_module}_SRCS=\"$ngx_module_srcs\"

    eval ${ngx_module}_MODULES=\"$ngx_module_name\"

    if [ -z "$ngx_module_order" -a \
         \( "$ngx_module_type" = "HTTP_FILTER" \
         -o "$ngx_module_type" = "HTTP_AUX_FILTER" \) ]
    then
        eval ${ngx_module}_ORDER=\"$ngx_module_name \
                                   ngx_http_copy_filter_module\"
    else
        eval ${ngx_module}_ORDER=\"$ngx_module_order\"
    fi

    if test -n "$ngx_module_incs"; then
        CORE_INCS="$CORE_INCS $ngx_module_incs"
    fi

    if test -n "$ngx_module_deps"; then
        NGX_ADDON_DEPS="$NGX_ADDON_DEPS $ngx_module_deps"
    fi

    libs=
    for lib in $ngx_module_libs
    do
        case $lib in

            LIBXSLT | LIBGD | GEOIP | PERL)
                libs="$libs \$NGX_LIB_$lib"

                if eval [ "\$USE_${lib}" = NO ] ; then
                    eval USE_${lib}=DYNAMIC
                fi
            ;;

            PCRE | OPENSSL | ZLIB)
                eval USE_${lib}=YES
            ;;

            MD5 | SHA1)
                # obsolete
            ;;

            *)
                libs="$libs $lib"
            ;;

        esac
    done
    eval ${ngx_module}_LIBS=\'$libs\'

elif [ "$ngx_module_link" = YES ]; then

    eval ${ngx_module_type}_MODULES=\"\$${ngx_module_type}_MODULES \
                                      $ngx_module_name\"

    eval ${ngx_var}_SRCS=\"\$${ngx_var}_SRCS $ngx_module_srcs\"

    if test -n "$ngx_module_incs"; then
        eval ${ngx_var}_INCS=\"\$${ngx_var}_INCS $ngx_module_incs\"
    fi

    if test -n "$ngx_module_deps"; then
        eval ${ngx_var}_DEPS=\"\$${ngx_var}_DEPS $ngx_module_deps\"
    fi

    for lib in $ngx_module_libs
    do
        case $lib in

            PCRE | OPENSSL | ZLIB | LIBXSLT | LIBGD | PERL | GEOIP)
                eval USE_${lib}=YES
            ;;

            MD5 | SHA1)
                # obsolete
            ;;

            *)
                CORE_LIBS="$CORE_LIBS $lib"
            ;;

        esac
    done

elif [ "$ngx_module_link" = ADDON ]; then

    eval ${ngx_module_type}_MODULES=\"\$${ngx_module_type}_MODULES \
                                      $ngx_module_name\"

    NGX_ADDON_SRCS="$NGX_ADDON_SRCS $ngx_module_srcs"

    if test -n "$ngx_module_incs"; then
        eval ${ngx_var}_INCS=\"\$${ngx_var}_INCS $ngx_module_incs\"
    fi

    if test -n "$ngx_module_deps"; then
        NGX_ADDON_DEPS="$NGX_ADDON_DEPS $ngx_module_deps"
    fi

    for lib in $ngx_module_libs
    do
        case $lib in

            PCRE | OPENSSL | ZLIB | LIBXSLT | LIBGD | PERL | GEOIP)
                eval USE_${lib}=YES
            ;;

            MD5 | SHA1)
                # obsolete
            ;;

            *)
                CORE_LIBS="$CORE_LIBS $lib"
            ;;

        esac
    done
fi