# centos 7
sudo yum install libatomic

# ubuntu 20.04
sudo apt install libatomic1 

git clone https://github.com/emqx/emqtt-bench.git
cd emqtt-bench
make

BUILD_WITHOUT_QUIC=1 make

$ ./emqtt_bench conn --help
Usage: emqtt_bench conn [--help <help>] [-d <dist>] [-h [<host>]]
                        [-p [<port>]] [-V [<version>]] [-c [<count>]]
                        [-n [<startnumber>]] [--load-qst <nst_dets_file>]
                        [-Q [<qoe>]] [-i [<interval>]] [-u <username>]
                        [-P <password>] [-k [<keepalive>]] [-C [<clean>]]
                        [-x [<expiry>]] [-S [<ssl>]]
                        [--certfile <certfile>] [--keyfile <keyfile>]
                        [--quic [<quic>]] [--ifaddr <ifaddr>]
                        [--prefix <prefix>] [-s [<shortids>]]
                        [-l <lowmem>]
                        [--num-retry-connect [<num_retry_connect>]]
                        [-R [<conn_rate>]]
                        [--force-major-gc-interval [<force_major_gc_interval>]]
                        [--log_to [<log_to>]]
                        [--prometheus]
                        [--restapi <ip>:<port> | <port>]

  --help                     help information
  -d, --dist                 enable distribution port
  -h, --host                 mqtt server hostname or comma-separated 
                             hostnames [default: localhost]
  -p, --port                 mqtt server port number [default: 1883]
  -V, --version              mqtt protocol version: 3 | 4 | 5 [default: 5]
  -c, --count                max count of clients [default: 200]
  -n, --startnumber          start number [default: 0]
  -Q, --qoe                  Enable QoE tracking [default: false]
  -i, --interval             interval of connecting to the broker 
                             [default: 10]
  -u, --username             username for connecting to server
  -P, --password             password for connecting to server
  -k, --keepalive            keep alive in seconds [default: 300]
  -C, --clean                clean session [default: true]
  -x, --session-expiry       Set 'Session-Expiry' for persistent sessions 
                             (seconds) [default: 0]
  -S, --ssl                  ssl socoket for connecting to server 
                             [default: false]
  --certfile                 client certificate for authentication, if 
                             required by server
  --keyfile                  client private key for authentication, if 
                             required by server
  --quic                     QUIC transport [default: false]
  --load-qst                 load quic session tickets from dets file
  --ifaddr                   local ipaddress or interface address
  --prefix                   client id prefix
  -s, --shortids             use short ids for client ids [default: false]
  -l, --lowmem               enable low mem mode, but use more CPU
  --num-retry-connect        number of times to retry estabilishing a 
                             connection before giving up [default: 0]
  -R, --connrate             connection rate(/s), default: 0, fallback to 
                             use --interval [default: 0]
  --force-major-gc-interval  interval in milliseconds in which a major GC 
                             will be forced on the bench processes.  a 
                             value of 0 means disabled (default).  this 
                             only takes effect when used together with 
                             --lowmem. [default: 0]
  --log_to                   Control where the log output goes. console: 
                             directly to the console      null: quietly, 
                             don't output any logs. [default: console]
  --prometheus               Enable metrics collection via Prometheus.
                             Usually used with --restapi to enable
                             scraping endpoint.
  --restapi                  Enable REST API for monitoring and control. 
                             For now only serves /metrics. 
                             Can be set to IP:Port to listen on a specific IP and Port,
                             or just Port to listen on all interfaces on
                             that port. [default: disabled]

./emqtt_bench conn -c 50000 -i 10

$ ./emqtt_bench sub --help
Usage: emqtt_bench sub [--help <help>] [-d <dist>] [-h [<host>]] [-p [<port>]] [-V [<version>]] [-c [<count>]]
                       [-n [<startnumber>]] [-i [<interval>]] [-t <topic>] [--payload-hdrs [<payload_hdrs>]] [-q [<qos>]]
                       [-Q [<qoe>]] [-u <username>] [-P <password>] [-k [<keepalive>]] [-C [<clean>]] [-x [<expiry>]]
                       [-S [<ssl>]] [--certfile <certfile>] [--keyfile <keyfile>] [--ws [<ws>]] [--quic [<quic>]]
                       [--load-qst <nst_dets_file>] [--ifaddr <ifaddr>] [--prefix <prefix>] [-s [<shortids>]] [-l <lowmem>]
                       [--num-retry-connect [<num_retry_connect>]] [-R [<conn_rate>]]
                       [--force-major-gc-interval [<force_major_gc_interval>]] [--log_to [<log_to>]]
                       [--prometheus]
                       [--restapi <ip>:<port> | <port>]

  --help                     help information
  -d, --dist                 enable distribution port
  -h, --host                 mqtt server hostname or comma-separated hostnames [default: localhost]
  -p, --port                 mqtt server port number [default: 1883]
  -V, --version              mqtt protocol version: 3 | 4 | 5 [default: 5]
  -c, --count                max count of clients [default: 200]
  -n, --startnumber          The start point when assigning sequence numbers to clients. This is useful when running 
                             multiple emqtt-bench instances to test the same broker (cluster), so the start number can be 
                             planned to avoid client ID collision [default: 0]
  -i, --interval             interval of connecting to the broker [default: 10]
  -t, --topic                topic subscribe, support %u, %c, %i variables
  --payload-hdrs             Handle the payload header from received message. Publish side must have the same option enabled 
                             in the same order. cnt64: Check the counter is strictly increasing. ts: publish latency counting. 
                             [default: ]
  -q, --qos                  subscribe qos [default: 0]
  -Q, --qoe                  Enable QoE tracking [default: false]
  -u, --username             username for connecting to server
  -P, --password             password for connecting to server
  -k, --keepalive            keep alive in seconds [default: 300]
  -C, --clean                clean start [default: true]
  -x, --session-expiry       Set 'Session-Expiry' for persistent sessions (seconds) [default: 0]
  -S, --ssl                  ssl socoket for connecting to server [default: false]
  --certfile                 client certificate for authentication, if required by server
  --keyfile                  client private key for authentication, if required by server
  --ws                       websocket transport [default: false]
  --quic                     QUIC transport [default: false]
  --load-qst                 load quic session tickets from dets file
  --ifaddr                   local ipaddress or interface address
  --prefix                   Client ID prefix. If not provided '$HOST_bench_(pub|sub)_$RANDOM_$N' is used, where $HOST is 
                             either the host name or the IP address provided in the --ifaddr option, $RANDOM is a random 
                             number and $N is the sequence number assigned for each client. If provided, the $RANDOM suffix 
                             will not be added.
  -s, --shortids             Use short client ID. If --prefix is provided, the prefix is added otherwise client ID is the 
                             assigned sequence number. [default: false]
  -l, --lowmem               enable low mem mode, but use more CPU
  --num-retry-connect        number of times to retry estabilishing a connection before giving up [default: 0]
  -R, --connrate             connection rate(/s), default: 0, fallback to use --interval [default: 0]
  --force-major-gc-interval  interval in milliseconds in which a major GC will be forced on the bench processes.  a value of 
                             0 means disabled (default).  this only takes effect when used together with --lowmem. [default: 
                             0]
  --log_to                   Control where the log output goes. console: directly to the console      null: quietly, don't 
                             output any logs. [default: console]
  --prometheus               Enable metrics collection via Prometheus.
                             Usually used with --restapi to enable
                             scraping endpoint.
  --restapi                  Enable REST API for monitoring and control. 
                             For now only serves /metrics. 
                             Can be set to IP:Port to listen on a specific IP and Port,
                             or just Port to listen on all interfaces on
                             that port. [default: disabled]

./emqtt_bench sub -c 50000 -i 10 -t bench/%i -q 2

Usage: emqtt_bench pub [--help <help>] [-d <dist>] [-h [<host>]] [-p [<port>]] [-V [<version>]] [-c [<count>]]
                       [-n [<startnumber>]] [-i [<interval>]] [-I [<interval_of_msg>]] [-u <username>] [-P <password>]
                       [-t <topic>] [--payload-hdrs [<payload_hdrs>]] [-s [<size>]] [-m <message>] [-q [<qos>]]
                       [-Q [<qoe>]] [-r [<retain>]] [-k [<keepalive>]] [-C [<clean>]] [-x [<expiry>]] [-L [<limit>]]
                       [-S [<ssl>]] [--certfile <certfile>] [--keyfile <keyfile>] [--ws [<ws>]] [--quic [<quic>]]
                       [--load-qst <nst_dets_file>] [--ifaddr <ifaddr>] [--prefix <prefix>] [-s [<shortids>]] [-l <lowmem>]
                       [-F [<inflight>]] [-w [<wait_before_publishing>]] [--max-random-wait [<max_random_wait>]]
                       [--min-random-wait [<min_random_wait>]] [--num-retry-connect [<num_retry_connect>]]
                       [-R [<conn_rate>]] [--force-major-gc-interval [<force_major_gc_interval>]] [--log_to [<log_to>]]
                       [--prometheus]
                       [--restapi <ip>:<port> | <port>]

  --help                        help information
  -d, --dist                    enable distribution port
  -h, --host                    mqtt server hostname or comma-separated hostnames [default: localhost]
  -p, --port                    mqtt server port number [default: 1883]
  -V, --version                 mqtt protocol version: 3 | 4 | 5 [default: 5]
  -c, --count                   max count of clients [default: 200]
  -n, --startnumber             The start point when assigning sequence numbers to clients. This is useful when running 
                                multiple emqtt-bench instances to test the same broker (cluster), so the start number can be 
                                planned to avoid client ID collision [default: 0]
  -i, --interval                interval of connecting to the broker [default: 10]
  -I, --interval_of_msg         interval of publishing message(ms) [default: 1000]
  -u, --username                username for connecting to server
  -P, --password                password for connecting to server
  -t, --topic                   topic subscribe, support %u, %c, %i, %s variables
  --payload-hdrs                 If set, add optional payload headers. cnt64: strictly increasing counter(64bit) per publisher 
                                ts: Timestamp when emit example: --payload-hdrs cnt64,ts [default: ]
  -s, --size                    payload size [default: 256]
  -m, --message                 set the message content for publish
  -q, --qos                     subscribe qos [default: 0]
  -Q, --qoe                     Enable QoE tracking [default: false]
  -r, --retain                  retain message [default: false]
  -k, --keepalive               keep alive in seconds [default: 300]
  -C, --clean                   clean start [default: true]
  -x, --session-expiry          Set 'Session-Expiry' for persistent sessions (seconds) [default: 0]
  -L, --limit                   The max message count to publish, 0 means unlimited [default: 0]
  -S, --ssl                     ssl socoket for connecting to server [default: false]
  --certfile                    client certificate for authentication, if required by server
  --keyfile                     client private key for authentication, if required by server
  --ws                          websocket transport [default: false]
  --quic                        QUIC transport [default: false]
  --load-qst                    load quic session tickets from dets file
  --ifaddr                      One or multiple (comma-separated) source IP addresses
  --prefix                      Client ID prefix. If not provided '$HOST_bench_(pub|sub)_$RANDOM_$N' is used, where $HOST is 
                                either the host name or the IP address provided in the --ifaddr option, $RANDOM is a random 
                                number and $N is the sequence number assigned for each client. If provided, the $RANDOM 
                                suffix will not be added.
  -s, --shortids                Use short client ID. If --prefix is provided, the prefix is added otherwise client ID is the 
                                assigned sequence number. [default: false]
  -l, --lowmem                  enable low mem mode, but use more CPU
  -F, --inflight                maximum inflight messages for QoS 1 an 2, value 0 for 'infinity' [default: 1]
  -w, --wait-before-publishing  wait for all publishers to have (at least tried to) connected before starting publishing 
                                [default: false]
  --max-random-wait             maximum randomized period in ms that each publisher will wait before starting to publish 
                                (uniform distribution) [default: 0]
  --min-random-wait             minimum randomized period in ms that each publisher will wait before starting to publish 
                                (uniform distribution) [default: 0]
  --num-retry-connect           number of times to retry estabilishing a connection before giving up [default: 0]
  -R, --connrate                connection rate(/s), default: 0, fallback to use --interval [default: 0]
  --force-major-gc-interval     interval in milliseconds in which a major GC will be forced on the bench processes.  a value 
                                of 0 means disabled (default).  this only takes effect when used together with --lowmem. 
                                [default: 0]
  --log_to                      Control where the log output goes. console: directly to the console      null: quietly, 
                                don't output any logs. [default: console]
  --prometheus                  Enable metrics collection via Prometheus.
                                Usually used with --restapi to enable
                                scraping endpoint.
  --restapi                     Enable REST API for monitoring and control. 
                                For now only serves /metrics. 
                                Can be set to IP:Port to listen on a specific IP and Port,
                                or just Port to listen on all interfaces on
                                that port. [default: disabled]

./emqtt_bench pub -c 100 -I 10 -t bench/%i -s 256

./emqtt_bench pub --ifaddr 192.168.1.10
./emqtt_bench sub --ifaddr 192.168.2.10

./emqtt_bench sub -c 100 -i 10 -t bench/%i -p 8883 --ssl
./emqtt_bench pub -c 100 -I 10 -t bench/%i -p 8883 -s 256 --ssl

./emqtt_bench sub -c 100 -i 10 -t bench/%i -p 8883 --ssl --certfile path/to/client-cert.pem --keyfile path/to/client-key.pem
./emqtt_bench pub -c 100 -i 10 -t bench/%i -s 256 -p 8883 --ssl --certfile path/to/client-cert.pem --keyfile path/to/client-key.pem

ulimit -n 200000
sudo sysctl -w net.ipv4.ip_local_port_range="1025 65534"