3.1.1.2. Compression

The user-data compression feature allows a DataWriter to compress the samples that it sends to matching DataReaders. Only the user payload is compressed, not the RTPS protocol headers. This compression feature can be configured using the compression_settings in the DATA_REPRESENTATION QoS Policy. For more information, see the “Data Compression” section in DATA_REPRESENTATION QosPolicy, in the RTI Connext Core Libraries User’s Manual.

The following tests have been performed by executing an RTI Perftest C++98 Publisher and Subscriber between two nodes, connected to a switch via Ethernet. Compression has been enabled with different combinations of settings, the communication has been restricted to a single interface, and the transport has been set to UDPv4.

For latency and throughput tests, the compression threshold is set to the default value (8192 bytes), so compression is disabled for sizes lower than this value. We assume that the performance for small sample sizes usually does not improve in terms of latency or throughput, but it still can be beneficial for reducing bandwidth utilization.

The data sent and used on these tests to measure the performance of the compression feature is text data corresponding to the logs generated by Connext in a real customer scenario. We parse the data and crop it into samples of different sizes. The gathered results show a lower performance than is possible, but a more realistic one. Keep in mind that the type of data sent has a huge impact on the compression algorithm behavior.

The network used for this test is the 1Gbps network where this feature is able to boost the throughput beyond the hardware limitation of 1Gbps.

Find information about the hardware, network, and command-line parameters after each of the tests.

Compression LZ4, Unkeyed, UDPv4, C++98

Linux x64 (1Gbps Network)

Minimum LatencyMaximum Throughput

The graph below shows the one-way latency without load between a Publisher and a Subscriber running in two Linux nodes connected locally in a 1Gbps network.

The compression settings used for these tests are as follows:

• compression_ids: LZ4

• writer_level: 5

• writer_threshold: 8192 (default)

Detailed Statistics

The following table contains the raw numbers presented by RTI Perftest. These numbers are the exact output with no further processing.

Reliable

Sample Size (Bytes)	Ave (μs)	Std (μs)	Min (μs)	Max (μs)	50% (μs)	90% (μs)	99% (μs)	99.99% (μs)	99.9999% (μs)
512	71	1.3	64	131	71	72	74	99	131
1024	83	2.2	67	140	84	85	87	112	140
2048	104	6.4	70	165	105	111	113	135	165
4096	130	15.0	71	258	132	148	157	173	258
8192	164	28.6	72	248	169	198	216	238	248
16384	215	48.3	79	314	227	269	299	310	314
32768	278	60.7	93	384	315	325	334	375	384
63000	340	61.0	119	475	363	391	414	426	475

Best Effort

Sample Size (Bytes)	Ave (μs)	Std (μs)	Min (μs)	Max (μs)	50% (μs)	90% (μs)	99% (μs)	99.99% (μs)	99.9999% (μs)
512	69	1.4	62	173	68	70	72	98	173
1024	82	2.1	67	138	82	83	84	111	138
2048	102	6.3	67	160	103	109	111	134	160
4096	128	14.9	70	212	130	146	155	171	212
8192	162	28.6	70	239	168	196	214	236	239
16384	213	48.3	79	310	225	267	297	307	310
32768	276	60.7	90	384	313	323	332	371	384
63000	338	61.0	116	483	361	389	412	425	483

Perftest Scripts

To produce these tests, we executed RTI Perftest for C++98. The exact script used can be found here:

#!/bin/bash
filename=$0
script_location=$(cd "$(dirname "$filename")" || exit 255; pwd)

export datasizes="32 64 128 256 512 1024 2048 4096 8192 16384 32768 63000"
export datasizes_extended="${datasizes} 100000 500000 1048576 1548576 4194304 10485760"

export domain="2"
export exec_time=20
export num_reps=1
export instance_number=100000
export core=0

# We will use some colors to improve visibility of errors and info messages.
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[0;33m'
BLUE='\033[0;34m'
LIGHTBLUE='\033[0;36m'
NC='\033[0m'
INFO_TAG="${GREEN}[INFO]:${NC}"
WARNING_TAG="${YELLOW}[WARNING]:${NC}"
ERROR_TAG="${RED}[ERROR]:${NC}"

export ip_machine_1="10.2.78.20"
export ip_machine_2="10.2.78.21"
export if10Gbps="enp1s0f0"
export if1Gbps="eno1"

################################################################################

function disable_colors() {
    export RED=""
    export GREEN=""
    export YELLOW=""
    export NC=""
    export BLUE=""
    export LIGHTBLUE=""
    export INFO_TAG="${GREEN}[INFO]:${NC}"
    export WARNING_TAG="${YELLOW}[WARNING]:${NC}"
    export ERROR_TAG="${RED}[ERROR]:${NC}"
}

function change_domain() {
    if [[ "$domain" == "1" ]]; then
        export domain="2"
    else
        export domain="1"
    fi
}

# Usage: execute_test <keyed/unkeyed> <rel/be> <datasizes> <batchSize>
function execute_test() {

    local keyed_unkeyed=$1
    local rel_be=$2
    local datasizes_test=$3
    local other_args=$4
    local name_suffix=$5

    local commands_string_test=$commands_string
    local tag=""

    if [[ "${keyed_unkeyed}" == "keyed" ]]; then
        commands_string_test="${commands_string_test} -keyed -instances $instance_number"
        tag="[${YELLOW}${transport}${NC}|${BLUE}K${NC}|"
    else
        tag="[${YELLOW}${transport}${NC}|${LIGHTBLUE}UK${NC}|"
    fi

    if [[ "${rel_be}" == "be" ]]; then
        commands_string_test="${commands_string_test} -bestEffort"
        tag="${tag}${YELLOW}BE${NC}]"
    else
        tag="${tag}${RED}REL${NC}]"
    fi

    tag="${tag}[${LIGHTBLUE}${lat_thr}${NC}]"

    local output_file=$output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}.csv

    if [[ "$role" == "pub" ]]; then
        echo -e "${YELLOW}[TEST]: $keyed_unkeyed, $rel_be. ${NC}"
    fi

    if [[ "$LANGUAGE" != "java" && "$LANGUAGE" != "cs" ]]; then
        export pre_command_string="taskset -c $core"
    fi

    if [[ "$LANGUAGE" == "python" ]]; then
        export pre_command_string="python3 "
    fi

    # Get the aprox time this will take:
    total_tests=$((`wc -w <<< "$datasizes_test"` * num_reps))
    total_time=$((total_tests * exec_time))

    touch $output_file
    local no_headers=""
    local current_test=0
    for index in $(seq 1 ${num_reps}); do
        for DATALEN in ${datasizes_test}; do
            current_test=$((current_test + 1))
            export command="$pre_command_string $executable -domain $domain -dataLen $DATALEN $commands_string_test $other_args $no_headers"
            if [[ "$role" == "pub" ]]; then
                echo -e "Test ${tag} (${current_test}/${total_tests}) -- Total time = ${total_time}s"
                echo -e ${BLUE}$command${NC}
            else
                echo -e ${LIGHTBLUE}$command${NC}
            fi
            if [[ "$LANGUAGE" == "cs" && "$role" == "pub" ]]; then
                sleep 3
            fi
            if [[ "$raw" == "1" && "$role" == "sub" ]]; then
                sleep 5
            fi
            if [[ "${get_netstat_info}" == "1" ]]; then
                echo -e "${INFO_TAG} Getting netstat info before"
                netstat -s -u | grep -e "error" -e "packet" > $output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}_netstat_before.txt
            fi
            eval $command >> $output_file;
            if [[ "${get_netstat_info}" == "1" ]]; then
                echo -e "${INFO_TAG} Getting netstat info after"
                netstat -s -u | grep -e "error" -e "packet" > $output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}_netstat_after.txt
                touch "$output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}_netstat.csv"
                python3 $script_location/../../../tools/diff_netstat_output.py \
                    -n $output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}_netstat_after.txt \
                    -o $output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}_netstat_before.txt \
                    -d $DATALEN $no_header_netstat \
                    -csv >> "$output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}_netstat.csv"
                rm -rf $output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}_netstat_*.txt
                no_header_netstat=" -nh"
            fi
            no_headers=" -noOutputHeaders"

            change_domain
        done
    done
}

################################################################################
# PARSE COMMAND LINE OPTIONS:

while [ "$1" != "" ]; do
    case $1 in
        --executable)
            executable=$2
            shift
            ;;
        --output-folder)
            output_folder=$2
            shift
            ;;
        --sub-folder)
            sub_folder=$2
            shift
            ;;
        --role)
            export role=$2
            shift
            ;;
        --core)
            export core=$2
            shift
            ;;
        --test-kind)
            export lat_thr=$2
            shift
            ;;
        --interface1)
            export interface=$2
            shift
            ;;
        --interface2)
            export interface2=$2
            shift
            ;;
        --ip1)
            export ip1=$2
            shift
            ;;
        --ip2)
            export ip2=$2
            shift
            ;;
        --repetitions)
            export num_reps=$2
            shift
            ;;
        --domain)
            export domain=$2
            shift
            ;;
        --execution-time)
            export exec_time=$2
            shift
            ;;
        --transport)
            export transport=$2
            shift
            ;;
        --datalen)
            export datalen_input=$2
            shift
            ;;
        --file-suffix)
            export file_suffix=$2
            shift
            ;;
        --executable-suffix)
            export executable_suffix=$2
            shift
            ;;
        --extra-arguments)
            export extra_arguments=$2
            shift
            ;;
        --extra-arguments-pub)
            export extra_arguments_pub=$2
            shift
            ;;
        --extra-arguments-sub)
            export extra_arguments_sub=$2
            shift
            ;;
        --skip-no-batching)
            export skip_no_batching="1"
            ;;
        --skip-be)
            export skip_be_tests="1"
            ;;
        --skip-rel)
            export skip_rel_tests="1"
            ;;
        --skip-keyed)
            export skip_keyed_data="1"
            ;;
        --skip-large-data)
            export skip_large_data="1"
            ;;
        --large-data)
            export large_data="1"
            ;;
        --keyed)
            export skip_unkeyed="1"
            ;;
        --unkeyed)
            export skip_keyed_data="1"
            ;;
        --no-batching)
            export no_batching_only="1"
            ;;
        --reliable)
            export skip_be_tests="1"
            ;;
        --best-effort)
            export skip_rel_tests="1"
            ;;
        --security)
            export security_only="$2"
            shift
            ;;
        --micro)
            export micro="1"
            ;;
        --raw | --raw-transport)
            export raw="1"
            ;;
        --tss)
            export tss="1"
            ;;
        --no-colors)
            export NO_COLORS="1"
            ;;
        --language)
            export LANGUAGE=$2
            shift
            ;;
        --loss-rate)
            export loss_rate=$2
            shift
            ;;
        --get-netstat-info)
            export get_netstat_info="1"
            ;;
        *)
            echo -e "unknown parameter \"$1\""
            exit 255
            ;;
    esac
    shift
done

if [[ "$NO_COLORS" == "1" ]]; then
    disable_colors
fi

export folder_base="$(dirname "${executable}")"/../../..

if [[ $LANGUAGE == "java"  || "$LANGUAGE" == "cs" ]]; then
    export folder_base="$(dirname "${executable}")"/../..
fi
if [[ $tss == "1" ]]; then
    export folder_base="$(dirname "${executable}")"/../../../../..
fi

if [[ "${executable_suffix}" != "" ]]; then
    export executable="${executable}${executable_suffix}"
fi

if [[ "${sub_folder}" != "" ]]; then
    export output_folder="${output_folder}/${sub_folder}"
fi

echo -e "${INFO_TAG} Perftest executable is: $executable"
echo -e "${INFO_TAG} Output folder is: $output_folder"

################################################################################

if [[ "$LANGUAGE" == "python" ]]; then
    export skip_keyed_data="1"
    export skip_large_data="1"
    export skip_be_tests="1"
    export skip_no_batching="1"
fi

if [[ "${skip_large_data}" == "1" ]]; then
    export datasizes_extended=${datasizes}
elif [[ "${large_data}" == "1" ]]; then
    export datasizes=${datasizes_extended}
fi

if [[ "${datalen_input}" != "" ]]; then
    echo -e "${YELLOW}[TEST] Testing only for ${datalen_input}${NC}"
    export datasizes=${datalen_input}
    export datasizes_extended=${datalen_input}
    if [[ "${no_batching_only}" != "1" ]]; then
        export skip_large_data="1"
    fi
fi

if [[ "$role" != "pub" && "$role" != "sub" ]]; then
    echo -e "${ERROR_TAG} It must be either publisher or subscriber"
    exit 255
fi

if [[ "$lat_thr" != "thr" && "$lat_thr" != "lat" ]]; then
    echo -e "${ERROR_TAG} It must be either lat or thr"
    exit 255
fi

if [[ "${interface}" == "" ]]; then
    echo "Using default nics"
    export nic_publisher=${ip_machine_1}
    export nic_subscriber=${ip_machine_2}
else
    export nic_publisher=$interface
    echo -e "${INFO_TAG} Using nic_publisher: ${nic_publisher}"

    if [[ "${interface2}" == "" ]]; then
        export nic_subscriber=$interface
    else
        export nic_subscriber=$interface2
    fi
    echo -e "${INFO_TAG} Using nic_subscriber: ${nic_subscriber}"

    if [[ "${ip1}" != "" ]]; then
        export ip_publisher=$ip1
        echo "Using ip_publisher: ${ip_publisher}"
    fi

    if [[ "${ip2}" != "" ]]; then
        export ip_subscriber=$ip2
        echo "Using ip_subscriber: ${ip_subscriber}"
    fi

fi

export transport_string="-transport $transport"

if [[ "$transport" == "UDPv4" ]]; then

    export transport_string_pub="$transport_string -nic $nic_publisher"
    export transport_string_sub="$transport_string -nic $nic_subscriber"

    if [[ "$micro" == "1" || "$raw" == "1" ]]; then
        export transport_string_pub="$transport_string_pub -peer ${ip_subscriber}"
        export transport_string_sub="$transport_string_sub -peer ${ip_publisher}"
    fi

elif [[ "$transport" == "TCP" ]]; then
    export transport_string_pub="$transport_string \
        -nic $nic_publisher \
        -peer 0@tcpv4_lan://${ip_subscriber}:7400"
    export transport_string_sub="$transport_string \
        -nic $nic_subscriber \
        -peer 0@tcpv4_lan://${ip_publisher}:7400"
elif [[ "$transport" == "TLS" ]]; then
    export transport_string_pub="$transport_string \
        -nic $nic_publisher \
        -peer tlsv4_lan://${ip_subscriber}:7400"
    export transport_string_sub="$transport_string \
        -nic $nic_subscriber \
        -peer tlsv4_lan://${ip_publisher}:7400"
elif [[ "$transport" == "UDPv4_WAN" ]]; then
    export transport_string_pub="$transport_string \
        -nic $nic_publisher \
        -transportPublicAddress $ip_publisher:7400"
    export transport_string_sub="$transport_string \
        -nic $nic_subscriber \
        -peer 0@udpv4_wan://${ip_publisher}:7400"
else
    export transport_string_pub="$transport_string"
    export transport_string_sub="$transport_string"
fi

################################################################################

export pub_string="-pub \
        ${transport_string_pub} \
        -noPrintIntervals \
        -executionTime $exec_time"

if [[ ${lat_thr} == "lat" ]]; then
    export pub_string="$pub_string \
        -latencyTest"
fi

export sub_string="-sub \
        ${transport_string_sub} \
        -noPrintIntervals"

if [[ "$role" == "pub" ]]; then
    echo -e "$INFO_TAG Publisher side running"
    export commands_string=${pub_string}
    export extra_arguments="${extra_arguments} ${extra_arguments_pub}"
else
    echo -e "$INFO_TAG Subscriber side running"
    export commands_string=${sub_string}
    export extra_arguments="${extra_arguments} ${extra_arguments_sub}"
fi

###############################################################################

echo -e "${INFO_TAG} Executing: /set_${lat_thr}_mode.sh"
sudo /set_${lat_thr}_mode.sh
sleep 5

echo -e "${INFO_TAG} Disabling any loss rate"
sudo tc qdisc add dev $nic_publisher root netem loss 0%
sudo tc qdisc del dev $nic_publisher root netem loss 0%

if [[ "$role" == "pub" && "${loss_rate}" != "" ]]; then
    echo -e "${INFO_TAG} Setting loss rate to ${loss_rate}%"
    sudo tc qdisc add dev $nic_publisher root netem loss $loss_rate%
fi

cd $folder_base
echo -e "${INFO_TAG} Folder Base is: $PWD"
mkdir -p $output_folder

# Tests that may use batching (when doing throughput tests)
if [[ ${no_batching_only} != "1" ]]; then

    # UNKEYED
    if [[ "${skip_unkeyed}" == "" ]]; then

        # RELIABLE
        if [[ "${skip_rel_tests}" == "" ]]; then
            execute_test "unkeyed" "rel" "${datasizes_extended}" "${extra_arguments}" "$file_suffix"
        fi

        # BEST EFFORT
        if [[ "${skip_be_tests}" == "" ]]; then
            execute_test "unkeyed" "be" "${datasizes}" "${extra_arguments}" "$file_suffix"
        fi
    fi

    # KEYED
    if [[ "${skip_keyed_data}" == "" ]]; then

        # RELIABLE
        if [[ "${skip_rel_tests}" == "" ]]; then
            execute_test "keyed" "rel" "${datasizes}" "${extra_arguments}" "$file_suffix"
        fi

        # BEST EFFORT
        if [[ "${skip_be_tests}" == "" ]]; then
            execute_test "keyed" "be" "${datasizes}" "${extra_arguments}" "$file_suffix"
        fi
    fi

fi

if [[ "${skip_no_batching}" == "" || "${no_batching_only}" == "1" ]]; then
    no_batching_tests="1"
fi

# Tests that will not use batching
if [[ "${lat_thr}" == "thr" && "${no_batching_tests}" == "1" ]]; then

    if [[ "$role" == "pub" ]]; then
        export commands_string="${commands_string} -batchSize 0"
    fi

    # UNKEYED
    if [[ "${skip_unkeyed}" == "" ]]; then

        # RELIABLE
        if [[ "${skip_rel_tests}" == "" ]]; then
            execute_test "unkeyed" "rel" "${datasizes}" "${extra_arguments}" "_noBatch${file_suffix}"
        fi

        # BEST EFFORT
        if [[ "${skip_be_tests}" == "" ]]; then
            execute_test "unkeyed" "be" "${datasizes}" "${extra_arguments}" "_noBatch${file_suffix}"
        fi
    fi
fi

if [[ "$role" == "pub" && "${loss_rate}" != "" ]]; then
    echo -e "${INFO_TAG} Disabling loss rate"
    sudo tc qdisc del dev $nic_publisher root netem loss $loss_rate%
fi

#!/bin/bash
filename=$0
script_location=$(cd "$(dirname "$filename")" || exit 255; pwd)

export input_params=$@

export datalen_input=""
while [ "$1" != "" ]; do
    case $1 in
        --executable)
            executable=$2
            shift
            ;;
        --test-kind)
            export lat_thr=$2
            shift
            ;;
        --datalen)
            export datalen_input=$2
            shift
            ;;
        *)
            ;;
    esac
    shift
done


if [[ ${datalen_input} == "" ]]; then
    export datalen_input="512 1024 2048 4096 8192 16384 32768 63000"
fi

# If the test is thr, then force no-batching. We need to handle this use-case.


${script_location}/../base_script/script.sh $input_params --transport UDPv4 \
    --skip-keyed --skip-no-batching \
    --file-suffix "_zlib${suffix}" \
    --datalen "${datalen_input}" \
    --extra-arguments-pub "-loadDataFromFile /home/perfuser/rtiperftest/payload_test/messages $thr_command" \
    --extra-arguments "-compressionId ZLIB \
                       -compressionThreshold 0 \
                       -compressionLevel 10"



if [[ "$lat_thr" == "thr" ]]; then
    export thr_command="-batchSize 0"
    export suffix="_noBatch"
fi

${script_location}/../base_script/script.sh $input_params --transport UDPv4 \
    --skip-no-batching --skip-keyed --skip-no-batching \
    --file-suffix "_lz4"\
    --datalen "${datalen_input}" \
    --extra-arguments-pub "-loadDataFromFile /home/perfuser/rtiperftest/payload_test/messages $thr_command" \
    --extra-arguments "-compressionId LZ4 \
                       -compressionThreshold 0 \
                       -compressionLevel 5"

# export folder_base="$(dirname "${executable}")"/../../..
# export PATH_TO_GOVERNANCE_FILES_FOLDER=$folder_base/resource/secure

# ${script_location}/../base_script/script.sh $input_params --transport UDPv4 \
#     --skip-no-batching --skip-keyed --skip-be \
#     --datalen "${datalen_input}" \
#     --file-suffix "_no_compression_security_data_encrypt"\
#     --extra-arguments-pub "-loadDataFromFile /home/perfuser/rtiperftest/payload_test/messages" \
#     --extra-arguments "-secureGovernanceFile $PATH_TO_GOVERNANCE_FILES_FOLDER/signed_PerftestGovernance_EncryptData.xml"

# ${script_location}/../base_script/script.sh $input_params --transport UDPv4 \
#     --skip-no-batching --skip-keyed --skip-be \
#     --datalen "${datalen_input}" \
#     --file-suffix "_zlib_security_data_encrypt"\
#     --extra-arguments-pub "-loadDataFromFile /home/perfuser/rtiperftest/payload_test/messages" \
#     --extra-arguments "-secureGovernanceFile $PATH_TO_GOVERNANCE_FILES_FOLDER/signed_PerftestGovernance_EncryptData.xml \
#                        -compressionId ZLIB \
#                        -compressionThreshold 0 \
#                        -compressionLevel 5"

Test Hardware

The following hardware was used to perform these tests:

Linux Nodes

Dell R340 Servers (13 Units)
Processor: Intel Xeon E-2278G (3.4-5GHz, 8c/16t, 16MB cache, 2 memory channels @2666MHz)
RAM: 4x 16GB 2666MHz DIMM (64GB RAM)
HD: 480GB SATA SSD
NIC 1: Intel 710 dual port 10Gbps SFP
OS: Ubuntu 20.04 -- gcc 9.3.0

Switch

Dell 2048 -- 10Gbps switch (10Gbps and 1Gbps interfaces)

Compression ZLIB, Unkeyed, UDPv4, C++98

Linux x64 (1Gbps Network)

Minimum LatencyMaximum Throughput

The graph below shows the one-way latency without load between a Publisher and a Subscriber running in two Linux nodes connected locally in a 1Gbps network.

The compression settings used for these tests are as follows:

• compression_ids: ZLIB

• writer_level: 5

• writer_threshold: 8192 (default)

Detailed Statistics

The following table contains the raw numbers presented by RTI Perftest. These numbers are the exact output with no further processing.

Reliable

Sample Size (Bytes)	Ave (μs)	Std (μs)	Min (μs)	Max (μs)	50% (μs)	90% (μs)	99% (μs)	99.99% (μs)	99.9999% (μs)
512	122	3.1	98	185	122	125	130	154	185
1024	131	6.0	100	267	130	138	143	168	267
2048	145	9.2	107	205	144	156	166	186	205
4096	170	15.6	120	291	171	189	206	235	291
8192	211	26.6	140	307	215	243	266	299	307
16384	288	43.6	189	460	300	337	372	443	460
32768	432	70.9	262	692	453	506	546	660	692
63000	685	112.3	395	977	727	794	848	953	977

Best Effort

Sample Size (Bytes)	Ave (μs)	Std (μs)	Min (μs)	Max (μs)	50% (μs)	90% (μs)	99% (μs)	99.99% (μs)	99.9999% (μs)
512	119	2.9	95	183	120	122	126	152	183
1024	129	5.9	98	198	128	136	141	165	198
2048	143	9.2	105	239	142	154	163	186	239
4096	168	15.3	118	268	168	187	201	222	268
8192	209	26.3	138	296	213	240	260	294	296
16384	286	43.5	186	442	298	334	369	439	442
32768	431	71.7	261	668	453	506	543	667	668
63000	682	112.1	394	950	724	790	843	948	950

Perftest Scripts

To produce these tests, we executed RTI Perftest for C++98. The exact script used can be found here:

#!/bin/bash
filename=$0
script_location=$(cd "$(dirname "$filename")" || exit 255; pwd)

export datasizes="32 64 128 256 512 1024 2048 4096 8192 16384 32768 63000"
export datasizes_extended="${datasizes} 100000 500000 1048576 1548576 4194304 10485760"

export domain="2"
export exec_time=20
export num_reps=1
export instance_number=100000
export core=0

# We will use some colors to improve visibility of errors and info messages.
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[0;33m'
BLUE='\033[0;34m'
LIGHTBLUE='\033[0;36m'
NC='\033[0m'
INFO_TAG="${GREEN}[INFO]:${NC}"
WARNING_TAG="${YELLOW}[WARNING]:${NC}"
ERROR_TAG="${RED}[ERROR]:${NC}"

export ip_machine_1="10.2.78.20"
export ip_machine_2="10.2.78.21"
export if10Gbps="enp1s0f0"
export if1Gbps="eno1"

################################################################################

function disable_colors() {
    export RED=""
    export GREEN=""
    export YELLOW=""
    export NC=""
    export BLUE=""
    export LIGHTBLUE=""
    export INFO_TAG="${GREEN}[INFO]:${NC}"
    export WARNING_TAG="${YELLOW}[WARNING]:${NC}"
    export ERROR_TAG="${RED}[ERROR]:${NC}"
}

function change_domain() {
    if [[ "$domain" == "1" ]]; then
        export domain="2"
    else
        export domain="1"
    fi
}

# Usage: execute_test <keyed/unkeyed> <rel/be> <datasizes> <batchSize>
function execute_test() {

    local keyed_unkeyed=$1
    local rel_be=$2
    local datasizes_test=$3
    local other_args=$4
    local name_suffix=$5

    local commands_string_test=$commands_string
    local tag=""

    if [[ "${keyed_unkeyed}" == "keyed" ]]; then
        commands_string_test="${commands_string_test} -keyed -instances $instance_number"
        tag="[${YELLOW}${transport}${NC}|${BLUE}K${NC}|"
    else
        tag="[${YELLOW}${transport}${NC}|${LIGHTBLUE}UK${NC}|"
    fi

    if [[ "${rel_be}" == "be" ]]; then
        commands_string_test="${commands_string_test} -bestEffort"
        tag="${tag}${YELLOW}BE${NC}]"
    else
        tag="${tag}${RED}REL${NC}]"
    fi

    tag="${tag}[${LIGHTBLUE}${lat_thr}${NC}]"

    local output_file=$output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}.csv

    if [[ "$role" == "pub" ]]; then
        echo -e "${YELLOW}[TEST]: $keyed_unkeyed, $rel_be. ${NC}"
    fi

    if [[ "$LANGUAGE" != "java" && "$LANGUAGE" != "cs" ]]; then
        export pre_command_string="taskset -c $core"
    fi

    if [[ "$LANGUAGE" == "python" ]]; then
        export pre_command_string="python3 "
    fi

    # Get the aprox time this will take:
    total_tests=$((`wc -w <<< "$datasizes_test"` * num_reps))
    total_time=$((total_tests * exec_time))

    touch $output_file
    local no_headers=""
    local current_test=0
    for index in $(seq 1 ${num_reps}); do
        for DATALEN in ${datasizes_test}; do
            current_test=$((current_test + 1))
            export command="$pre_command_string $executable -domain $domain -dataLen $DATALEN $commands_string_test $other_args $no_headers"
            if [[ "$role" == "pub" ]]; then
                echo -e "Test ${tag} (${current_test}/${total_tests}) -- Total time = ${total_time}s"
                echo -e ${BLUE}$command${NC}
            else
                echo -e ${LIGHTBLUE}$command${NC}
            fi
            if [[ "$LANGUAGE" == "cs" && "$role" == "pub" ]]; then
                sleep 3
            fi
            if [[ "$raw" == "1" && "$role" == "sub" ]]; then
                sleep 5
            fi
            if [[ "${get_netstat_info}" == "1" ]]; then
                echo -e "${INFO_TAG} Getting netstat info before"
                netstat -s -u | grep -e "error" -e "packet" > $output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}_netstat_before.txt
            fi
            eval $command >> $output_file;
            if [[ "${get_netstat_info}" == "1" ]]; then
                echo -e "${INFO_TAG} Getting netstat info after"
                netstat -s -u | grep -e "error" -e "packet" > $output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}_netstat_after.txt
                touch "$output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}_netstat.csv"
                python3 $script_location/../../../tools/diff_netstat_output.py \
                    -n $output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}_netstat_after.txt \
                    -o $output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}_netstat_before.txt \
                    -d $DATALEN $no_header_netstat \
                    -csv >> "$output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}_netstat.csv"
                rm -rf $output_folder/${lat_thr}_${role}_${keyed_unkeyed}_${rel_be}${name_suffix}_netstat_*.txt
                no_header_netstat=" -nh"
            fi
            no_headers=" -noOutputHeaders"

            change_domain
        done
    done
}

################################################################################
# PARSE COMMAND LINE OPTIONS:

while [ "$1" != "" ]; do
    case $1 in
        --executable)
            executable=$2
            shift
            ;;
        --output-folder)
            output_folder=$2
            shift
            ;;
        --sub-folder)
            sub_folder=$2
            shift
            ;;
        --role)
            export role=$2
            shift
            ;;
        --core)
            export core=$2
            shift
            ;;
        --test-kind)
            export lat_thr=$2
            shift
            ;;
        --interface1)
            export interface=$2
            shift
            ;;
        --interface2)
            export interface2=$2
            shift
            ;;
        --ip1)
            export ip1=$2
            shift
            ;;
        --ip2)
            export ip2=$2
            shift
            ;;
        --repetitions)
            export num_reps=$2
            shift
            ;;
        --domain)
            export domain=$2
            shift
            ;;
        --execution-time)
            export exec_time=$2
            shift
            ;;
        --transport)
            export transport=$2
            shift
            ;;
        --datalen)
            export datalen_input=$2
            shift
            ;;
        --file-suffix)
            export file_suffix=$2
            shift
            ;;
        --executable-suffix)
            export executable_suffix=$2
            shift
            ;;
        --extra-arguments)
            export extra_arguments=$2
            shift
            ;;
        --extra-arguments-pub)
            export extra_arguments_pub=$2
            shift
            ;;
        --extra-arguments-sub)
            export extra_arguments_sub=$2
            shift
            ;;
        --skip-no-batching)
            export skip_no_batching="1"
            ;;
        --skip-be)
            export skip_be_tests="1"
            ;;
        --skip-rel)
            export skip_rel_tests="1"
            ;;
        --skip-keyed)
            export skip_keyed_data="1"
            ;;
        --skip-large-data)
            export skip_large_data="1"
            ;;
        --large-data)
            export large_data="1"
            ;;
        --keyed)
            export skip_unkeyed="1"
            ;;
        --unkeyed)
            export skip_keyed_data="1"
            ;;
        --no-batching)
            export no_batching_only="1"
            ;;
        --reliable)
            export skip_be_tests="1"
            ;;
        --best-effort)
            export skip_rel_tests="1"
            ;;
        --security)
            export security_only="$2"
            shift
            ;;
        --micro)
            export micro="1"
            ;;
        --raw | --raw-transport)
            export raw="1"
            ;;
        --tss)
            export tss="1"
            ;;
        --no-colors)
            export NO_COLORS="1"
            ;;
        --language)
            export LANGUAGE=$2
            shift
            ;;
        --loss-rate)
            export loss_rate=$2
            shift
            ;;
        --get-netstat-info)
            export get_netstat_info="1"
            ;;
        *)
            echo -e "unknown parameter \"$1\""
            exit 255
            ;;
    esac
    shift
done

if [[ "$NO_COLORS" == "1" ]]; then
    disable_colors
fi

export folder_base="$(dirname "${executable}")"/../../..

if [[ $LANGUAGE == "java"  || "$LANGUAGE" == "cs" ]]; then
    export folder_base="$(dirname "${executable}")"/../..
fi
if [[ $tss == "1" ]]; then
    export folder_base="$(dirname "${executable}")"/../../../../..
fi

if [[ "${executable_suffix}" != "" ]]; then
    export executable="${executable}${executable_suffix}"
fi

if [[ "${sub_folder}" != "" ]]; then
    export output_folder="${output_folder}/${sub_folder}"
fi

echo -e "${INFO_TAG} Perftest executable is: $executable"
echo -e "${INFO_TAG} Output folder is: $output_folder"

################################################################################

if [[ "$LANGUAGE" == "python" ]]; then
    export skip_keyed_data="1"
    export skip_large_data="1"
    export skip_be_tests="1"
    export skip_no_batching="1"
fi

if [[ "${skip_large_data}" == "1" ]]; then
    export datasizes_extended=${datasizes}
elif [[ "${large_data}" == "1" ]]; then
    export datasizes=${datasizes_extended}
fi

if [[ "${datalen_input}" != "" ]]; then
    echo -e "${YELLOW}[TEST] Testing only for ${datalen_input}${NC}"
    export datasizes=${datalen_input}
    export datasizes_extended=${datalen_input}
    if [[ "${no_batching_only}" != "1" ]]; then
        export skip_large_data="1"
    fi
fi

if [[ "$role" != "pub" && "$role" != "sub" ]]; then
    echo -e "${ERROR_TAG} It must be either publisher or subscriber"
    exit 255
fi

if [[ "$lat_thr" != "thr" && "$lat_thr" != "lat" ]]; then
    echo -e "${ERROR_TAG} It must be either lat or thr"
    exit 255
fi

if [[ "${interface}" == "" ]]; then
    echo "Using default nics"
    export nic_publisher=${ip_machine_1}
    export nic_subscriber=${ip_machine_2}
else
    export nic_publisher=$interface
    echo -e "${INFO_TAG} Using nic_publisher: ${nic_publisher}"

    if [[ "${interface2}" == "" ]]; then
        export nic_subscriber=$interface
    else
        export nic_subscriber=$interface2
    fi
    echo -e "${INFO_TAG} Using nic_subscriber: ${nic_subscriber}"

    if [[ "${ip1}" != "" ]]; then
        export ip_publisher=$ip1
        echo "Using ip_publisher: ${ip_publisher}"
    fi

    if [[ "${ip2}" != "" ]]; then
        export ip_subscriber=$ip2
        echo "Using ip_subscriber: ${ip_subscriber}"
    fi

fi

export transport_string="-transport $transport"

if [[ "$transport" == "UDPv4" ]]; then

    export transport_string_pub="$transport_string -nic $nic_publisher"
    export transport_string_sub="$transport_string -nic $nic_subscriber"

    if [[ "$micro" == "1" || "$raw" == "1" ]]; then
        export transport_string_pub="$transport_string_pub -peer ${ip_subscriber}"
        export transport_string_sub="$transport_string_sub -peer ${ip_publisher}"
    fi

elif [[ "$transport" == "TCP" ]]; then
    export transport_string_pub="$transport_string \
        -nic $nic_publisher \
        -peer 0@tcpv4_lan://${ip_subscriber}:7400"
    export transport_string_sub="$transport_string \
        -nic $nic_subscriber \
        -peer 0@tcpv4_lan://${ip_publisher}:7400"
elif [[ "$transport" == "TLS" ]]; then
    export transport_string_pub="$transport_string \
        -nic $nic_publisher \
        -peer tlsv4_lan://${ip_subscriber}:7400"
    export transport_string_sub="$transport_string \
        -nic $nic_subscriber \
        -peer tlsv4_lan://${ip_publisher}:7400"
elif [[ "$transport" == "UDPv4_WAN" ]]; then
    export transport_string_pub="$transport_string \
        -nic $nic_publisher \
        -transportPublicAddress $ip_publisher:7400"
    export transport_string_sub="$transport_string \
        -nic $nic_subscriber \
        -peer 0@udpv4_wan://${ip_publisher}:7400"
else
    export transport_string_pub="$transport_string"
    export transport_string_sub="$transport_string"
fi

################################################################################

export pub_string="-pub \
        ${transport_string_pub} \
        -noPrintIntervals \
        -executionTime $exec_time"

if [[ ${lat_thr} == "lat" ]]; then
    export pub_string="$pub_string \
        -latencyTest"
fi

export sub_string="-sub \
        ${transport_string_sub} \
        -noPrintIntervals"

if [[ "$role" == "pub" ]]; then
    echo -e "$INFO_TAG Publisher side running"
    export commands_string=${pub_string}
    export extra_arguments="${extra_arguments} ${extra_arguments_pub}"
else
    echo -e "$INFO_TAG Subscriber side running"
    export commands_string=${sub_string}
    export extra_arguments="${extra_arguments} ${extra_arguments_sub}"
fi

###############################################################################

echo -e "${INFO_TAG} Executing: /set_${lat_thr}_mode.sh"
sudo /set_${lat_thr}_mode.sh
sleep 5

echo -e "${INFO_TAG} Disabling any loss rate"
sudo tc qdisc add dev $nic_publisher root netem loss 0%
sudo tc qdisc del dev $nic_publisher root netem loss 0%

if [[ "$role" == "pub" && "${loss_rate}" != "" ]]; then
    echo -e "${INFO_TAG} Setting loss rate to ${loss_rate}%"
    sudo tc qdisc add dev $nic_publisher root netem loss $loss_rate%
fi

cd $folder_base
echo -e "${INFO_TAG} Folder Base is: $PWD"
mkdir -p $output_folder

# Tests that may use batching (when doing throughput tests)
if [[ ${no_batching_only} != "1" ]]; then

    # UNKEYED
    if [[ "${skip_unkeyed}" == "" ]]; then

        # RELIABLE
        if [[ "${skip_rel_tests}" == "" ]]; then
            execute_test "unkeyed" "rel" "${datasizes_extended}" "${extra_arguments}" "$file_suffix"
        fi

        # BEST EFFORT
        if [[ "${skip_be_tests}" == "" ]]; then
            execute_test "unkeyed" "be" "${datasizes}" "${extra_arguments}" "$file_suffix"
        fi
    fi

    # KEYED
    if [[ "${skip_keyed_data}" == "" ]]; then

        # RELIABLE
        if [[ "${skip_rel_tests}" == "" ]]; then
            execute_test "keyed" "rel" "${datasizes}" "${extra_arguments}" "$file_suffix"
        fi

        # BEST EFFORT
        if [[ "${skip_be_tests}" == "" ]]; then
            execute_test "keyed" "be" "${datasizes}" "${extra_arguments}" "$file_suffix"
        fi
    fi

fi

if [[ "${skip_no_batching}" == "" || "${no_batching_only}" == "1" ]]; then
    no_batching_tests="1"
fi

# Tests that will not use batching
if [[ "${lat_thr}" == "thr" && "${no_batching_tests}" == "1" ]]; then

    if [[ "$role" == "pub" ]]; then
        export commands_string="${commands_string} -batchSize 0"
    fi

    # UNKEYED
    if [[ "${skip_unkeyed}" == "" ]]; then

        # RELIABLE
        if [[ "${skip_rel_tests}" == "" ]]; then
            execute_test "unkeyed" "rel" "${datasizes}" "${extra_arguments}" "_noBatch${file_suffix}"
        fi

        # BEST EFFORT
        if [[ "${skip_be_tests}" == "" ]]; then
            execute_test "unkeyed" "be" "${datasizes}" "${extra_arguments}" "_noBatch${file_suffix}"
        fi
    fi
fi

if [[ "$role" == "pub" && "${loss_rate}" != "" ]]; then
    echo -e "${INFO_TAG} Disabling loss rate"
    sudo tc qdisc del dev $nic_publisher root netem loss $loss_rate%
fi

#!/bin/bash
filename=$0
script_location=$(cd "$(dirname "$filename")" || exit 255; pwd)

export input_params=$@

export datalen_input=""
while [ "$1" != "" ]; do
    case $1 in
        --executable)
            executable=$2
            shift
            ;;
        --test-kind)
            export lat_thr=$2
            shift
            ;;
        --datalen)
            export datalen_input=$2
            shift
            ;;
        *)
            ;;
    esac
    shift
done


if [[ ${datalen_input} == "" ]]; then
    export datalen_input="512 1024 2048 4096 8192 16384 32768 63000"
fi

# If the test is thr, then force no-batching. We need to handle this use-case.


${script_location}/../base_script/script.sh $input_params --transport UDPv4 \
    --skip-keyed --skip-no-batching \
    --file-suffix "_zlib${suffix}" \
    --datalen "${datalen_input}" \
    --extra-arguments-pub "-loadDataFromFile /home/perfuser/rtiperftest/payload_test/messages $thr_command" \
    --extra-arguments "-compressionId ZLIB \
                       -compressionThreshold 0 \
                       -compressionLevel 10"



if [[ "$lat_thr" == "thr" ]]; then
    export thr_command="-batchSize 0"
    export suffix="_noBatch"
fi

${script_location}/../base_script/script.sh $input_params --transport UDPv4 \
    --skip-no-batching --skip-keyed --skip-no-batching \
    --file-suffix "_lz4"\
    --datalen "${datalen_input}" \
    --extra-arguments-pub "-loadDataFromFile /home/perfuser/rtiperftest/payload_test/messages $thr_command" \
    --extra-arguments "-compressionId LZ4 \
                       -compressionThreshold 0 \
                       -compressionLevel 5"

# export folder_base="$(dirname "${executable}")"/../../..
# export PATH_TO_GOVERNANCE_FILES_FOLDER=$folder_base/resource/secure

# ${script_location}/../base_script/script.sh $input_params --transport UDPv4 \
#     --skip-no-batching --skip-keyed --skip-be \
#     --datalen "${datalen_input}" \
#     --file-suffix "_no_compression_security_data_encrypt"\
#     --extra-arguments-pub "-loadDataFromFile /home/perfuser/rtiperftest/payload_test/messages" \
#     --extra-arguments "-secureGovernanceFile $PATH_TO_GOVERNANCE_FILES_FOLDER/signed_PerftestGovernance_EncryptData.xml"

# ${script_location}/../base_script/script.sh $input_params --transport UDPv4 \
#     --skip-no-batching --skip-keyed --skip-be \
#     --datalen "${datalen_input}" \
#     --file-suffix "_zlib_security_data_encrypt"\
#     --extra-arguments-pub "-loadDataFromFile /home/perfuser/rtiperftest/payload_test/messages" \
#     --extra-arguments "-secureGovernanceFile $PATH_TO_GOVERNANCE_FILES_FOLDER/signed_PerftestGovernance_EncryptData.xml \
#                        -compressionId ZLIB \
#                        -compressionThreshold 0 \
#                        -compressionLevel 5"

Test Hardware

The following hardware was used to perform these tests:

Linux Nodes

Dell R340 Servers (13 Units)
Processor: Intel Xeon E-2278G (3.4-5GHz, 8c/16t, 16MB cache, 2 memory channels @2666MHz)
RAM: 4x 16GB 2666MHz DIMM (64GB RAM)
HD: 480GB SATA SSD
NIC 1: Intel 710 dual port 10Gbps SFP
OS: Ubuntu 20.04 -- gcc 9.3.0

Switch

Dell 2048 -- 10Gbps switch (10Gbps and 1Gbps interfaces)

Compression Bandwidth Savings

The following table contains the bandwidth savings gain by enabling compression with ZLIB, which is one of algorithms with a higher compression ratio and the only one that can be used in combination with batching.

The compression settings used for these tests are as follows:

• compression_ids: ZLIB

• writer_compression_level: 10 (best compression possible, default setting)

• writer_compression_threshold: 0 (try to compress all samples)

The data used for this test is the same as used in the previous latency and throughput tests. In this test, each sample has its own size.

This test uses the compression example available in the github example repository: https://github.com/rticommunity/rticonnextdds-examples/tree/develop/examples/connext_dds/compression.

Batching	NONE Compression (Mb)	ZLIB Compression(Mb)	Diff Saved Mb	Diff Saved %
Disabled	70.59	53.74	16.85	23.87
2 samples	69.40	37.08	32.32	46.57
5 samples	69.26	22.08	47.18	68.12
10 samples	69.25	17.02	52.23	75.42

These results show up to a 75% reduction in network bandwidth utilization by using ZLIB in combination with batching, in a real use-case scenario.