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Updated: July 2017

rds-stress (1)


rds-stress - send messages between processes over RDS sockets


rds-stress [-p port_number] -r [receive_address] [-s send_address]
[-Q tos] [-a ack_bytes] [-q request_bytes] [-D rdma_bytes]
[-d queue_depth] [-t nr_tasks] [-T time] [-c] [-R] [-V] [-v]


RDS-STRESS(1)               General Commands Manual              RDS-STRESS(1)

       rds-stress - send messages between processes over RDS sockets


              rds-stress [-p port_number] -r [receive_address] [-s send_address]
                    [-Q tos] [-a ack_bytes] [-q request_bytes] [-D rdma_bytes]
                    [-d queue_depth] [-t nr_tasks] [-T time] [-c] [-R] [-V] [-v]

       rds-stress  sends  messages  between  groups  tasks, usually running on
       seperate machines.

       First a passive receiving instance is started.

                        $ rds-stress

       Then an active sending instance is started, giving it the  address  and
       port  at which it will find a listening passive receiver.  In addition,
       it is given configuration options which both instances will use.

                        $ rds-stress -s recvhost -p 4000 -t 1 -d 1

       The active sender will  parse  the  options,  connect  to  the  passive
       receiver,  and  send the options over this connection.  From this point
       on both instances exhibit the exact same behaviour.

       They will create a number of child tasks as specified by the -t option.
       Once the children are created the parent sleeps for a second at a time,
       printing a summary of statistics at each interval.

       Each child will open an RDS socket, each binding to a  port  number  in
       order after the port number given on the command line.  The first child
       would bind to port 4001 in our example.  Each child sets the  send  and
       receive  buffers  to  exactly  fit the number of messages, requests and
       acks, that will be in flight as determind by  the  command  line  argu-

       The  children  then  enter their loop.  They will keep a number of sent
       messages outstanding as specified by the -d option.   When  they  reach
       this limit they will wait to receive acks which will allow them to send
       again.  As they receive messages from their peers they immediately send

       Every second, the parent process will display statistics of the ongoing
       stress test. The output is described in section OUTPUT below.

       If the -T option is given, the test will terminate after the  specified
       time, and a summary is printed.

       Each  child maintains outstanding messages to all other children of the
       other instance.  They do not send to their siblings.

       The following options are available for use on the command line:

       -p  port_number
              Each parent binds a TCP socket to this  port  number  and  their
              respective address.  They will trade the negotiated options over
              this socket.  Each child will bind an RDS socket to the range of
              ports  immediately following this port number, for as many chil-
              dren as there are.

       -s send_address
              A connection attempt is made to this address.  Once its complete
              and  the  options are sent over it then children will be created
              and work will proceed.

       -r receive_address
              This specifies the address that messages will be sent from.   If
              -s  is  not  specified then rds-stress waits for a connection on
              this address before proceeding.

              If this option is not given, rds-stress will choose an appropri-
              ate address.  The passive process will accept connections on all
              local interfaces, and obtain the address once the  control  con-
              nection  is established.  The active process will choose a local
              address based on the interface through which it connects to  the
              destination address.

       -Q tos Uses  the RDS connection between IP addresses with the specified
              tos value. By default, the base (tos  =  0)  RDS  connection  is
              used.  Valid values are 0-255.

       -a ack_bytes
              This  specifies the size of the ack messages, in bytes. There is
              a minimum size which depends on the format of the ack  messages,
              which may change over time.  See section "Message Sizes" below.

       -q request_bytes
              This  specifies  the size of the request messages, in bytes.  It
              also has a minimum size which may change over time.  See section
              "Message Sizes" below.

       -D rdma_bytes
              RDSv3  is  capable  of  transmitting  part of a message via RDMA
              directly from application buffer  to  application  buffer.  This
              option  enables  RDMA  support  in  rds-stress:  request packets
              include parameters for an RDMA READ or  WRITE  operation,  which
              the  receiving  process  executes  at the time the ACK packet is
              sent.  See section "Message Sizes" below.

       -d queue_depth
              Each child will try to maintain this  many  sent  messages  out-
              standing to each of its peers on the remote address.

       -t nr_tasks
              Each parent will create this many children tasks.

       -T seconds
              Specify the duration of the test run. After the specified number
              of seconds, all processes on both ends of  the  connection  will
              terminate,  and  the  active  instance  will print a summary. By
              default, rds-stress will keep on sending and receiving messages.

       -z     This flag can be used in conjunction with -T. It suppresses  the
              ongoing display of statistics, and prints a summary only.

       -c     This  causes rds-stress to create child tasks which just consume
              CPU cycles.  One task is created for each  CPU  in  the  system.
              First  each child observes the maximum rate at which it can con-
              sume cycles.  This means that this option should only  be  given
              on an idle system.  rds-stress can then calculate the CPU use of
              the system by observing the lesser rate at  which  the  children
              consume  cycles.  This option is *not* shared between the active
              and passive instances.  It must be specified on each  rds-stress
              command line.

       -R     This  tells  the  rds-stress parent process to run with SCHED_RR
              priority, giving it precedence over the child processes. This is
              useful when running with lots of tasks, where there is a risk of
              the  child  processes  starving  the  parent,  and  skewing  the

       -v     With this option enabled, packets are filled with a pattern that
              is verified by the receiver. This check  can  help  detect  data
              corruption occuring under high load.

          Message Sizes
              Options  which  set a message size (such as -a) specify a number
              of bytes by default. By appending K, M, or G,  you  can  specify
              the size in kilobytes, megabytes or gigabytes, respectively. For
              instance, the following will run rds-stress with a  message  and
              ACK  size  of  1024  bytes,  and an RDMA message size of 1048576

                   rds-stress ... -q 1K -a 1K -D 1M

       Each parent outputs columns of statistics at a regular interval:

       tsks    The number of child tasks which are running.

       tx/s    The number of sendmsg() calls that all children are  executing,
               per second.

       rx/s    The  number of recvmsg() calls that all children are executing,
               per second.

       tx+rx K/s
               The total number of bytes that are  flowing  through  sendmsg()
               and recvmsg() for all children.  This includes both request and
               ack messages.

       mbi K/s The total number of bytes that  are  being  received  via  RDMA
               READs and WRITEs for all children.

       mbo K/s The  total  number  of bytes that are being transmited via RDMA
               READs and WRITEs for all children.

       tx us/c The average number of microseconds spent in sendmsg() calls.

       rtt us  The average round trip time for a request and ack message pair.
               This  measures  the  total  time  between  when  a task sends a
               request and when it finally receives the ack for that  message.
               Because  it includes the time it takes for the receiver to wake
               up, receive the message, and send an ack, it  can  grow  to  be
               quite large under load.

       cpu %   This  is  the  percentage  of  available  CPU resources on this
               machine that are being consumed since rds-stress  started  run-
               ning.  It will show -1.00 if -c is not given.  It is calculated
               based on the amount of CPU resources that CPU soaking tasks are
               able  to  consume.  This lets it measure CPU use by the system,
               say in interrupt handlers, that task-based CPU accounting  does
               not  include.  For this to work rds-stress must be started with
               -c on an idle system.

       See attributes(5) for descriptions of the following attributes:

       |Availability   | network/open-fabrics  |
       |Stability      | Pass-through volatile |
       This    software    was    built    from    source     available     at
       https://java.net/projects/solaris-userland.    The  original  community
       source   was   downloaded    from     ['http://download.oracle.com/otn-
       pub/oss/networking/libsif-1.0.tar.gz',            'https://www.openfab-
       verbs-1.1.8.tar.gz',                 'https://www.openfabrics.org/down-
       loads/libmlx4/libmlx4-1.0.6.tar.gz', 'https://www.openfabrics.org/down-
       loads/libsdp/libsdp-1.1.108-0.15.gd7fdb72.tar.gz',   'https://www.open-
       mad-1.3.12.tar.gz',      'https://www.openfabrics.org/downloads/manage-
       ment/libibumad-',     'https://www.openfabrics.org/down-
       loads/management/opensm-3.3.19.tar.gz',           'https://www.openfab-

       Further information about this software can be found on the open source
       community website at http://www.openfabrics.org/.

                                  May 15, 2007                   RDS-STRESS(1)